National Library of Energy BETA

Sample records for bed consequence modeling

  1. Mathematical modeling of fluidized bed reactors 

    E-Print Network [OSTI]

    Nasif, Nilufer Havva

    1985-01-01

    -C. Computational Procedure. II-C-1. Bed Expansion II-C-2. Total Number of Mass Transfer Units II-C-3. Effective Bubble Size (s) II-C-4. Conversion. III COMPARISON OF MATHEMATICAL MODELS FOR A FIRST ORDER REACTION. III-A. The Davidson and Harrison Model (DHM...) Page 14 18 18 19 21 22 22 III-A-1. III-A-2. DHPM Model with Constant Bubble Size. DHPM Model with Variable Bubble Size, 22 23 III-A-3. III-A-4. DHPF Model with Size. DHPF Model with Size. Constant Bubble Variable Bubble 24 25...

  2. Predictive models of circulating fluidized bed combustors

    SciTech Connect (OSTI)

    Gidaspow, D.

    1992-07-01

    Steady flows influenced by walls cannot be described by inviscid models. Flows in circulating fluidized beds have significant wall effects. Particles in the form of clusters or layers can be seen to run down the walls. Hence modeling of circulating fluidized beds (CFB) without a viscosity is not possible. However, in interpreting Equations (8-1) and (8-2) it must be kept in mind that CFB or most other two phase flows are never in a true steady state. Then the viscosity in Equations (8-1) and (8-2) may not be the true fluid viscosity to be discussed next, but an Eddy type viscosity caused by two phase flow oscillations usually referred to as turbulence. In view of the transient nature of two-phase flow, the drag and the boundary layer thickness may not be proportional to the square root of the intrinsic viscosity but depend upon it to a much smaller extent. As another example, liquid-solid flow and settling of colloidal particles in a lamella electrosettler the settling process is only moderately affected by viscosity. Inviscid flow with settling is a good first approximation to this electric field driven process. The physical meaning of the particulate phase viscosity is described in detail in the chapter on kinetic theory. Here the conventional derivation resented in single phase fluid mechanics is generalized to multiphase flow.

  3. Regression models Consequences of auto-generation

    E-Print Network [OSTI]

    McCullagh, Peter

    Regression models Consequences of auto-generation All creatures great and small Inference University of Chicago Statslab Cambridge Nov 14 2008 Peter McCullagh Auto-generated units #12;Regression Regression models Gaussian models Binary regression model Attenuation of treatment effect Problems

  4. Models to interpret bed-form geometries from cross-bed data

    SciTech Connect (OSTI)

    Luthi, S.M. (Schlumberger-Doll Research, Ridgefield, CT (USA)); Banavar, J.R. (Pennsylvania State Univ., University Park (USA)); Bayer, U. (Institute Erdoel und Organische Chemie, Kernforschungsanlage Juelich (West Germany))

    1990-05-01

    To improve the understanding of the relation of cross-bed azimuth distributions to bed-forms, geometric models were developed for migrating bed forms using a minimum number of parameters. Semielliptical and sinusoidal bed-form crestlines were modeled with curvature and sinuosity as parameters. Both bedform crestlines are propagated at various angles of migration over a finite area of deposition. Two computational approaches are used, a statistical random sampling (Monte Carlo) technique over the area of the deposit, and an analytical method based on topology and differential geometry. The resulting foreset azimuth distributions provide a catalog for a variety of simulations. The resulting thickness distributions have a simple shape and can be combined with the azimuth distributions to further constrain the cross-strata geometry. Paleocurrent directions obtained by these models can differ substantially from other methods, especially for obliquely migrating low-curvature bed forms. Interpretation of foreset azimuth data from outcrops and wells can be done either by visual comparison with the cataloged distributions, or by iterative computational fits. Studied examples include eolian cross-strata from the Permian Rotliegendes in the North Sea, fluvial dunes from the Devonian in the Catskills (New York state), the Triassic Schilfsandstein (Federal Republic of Germany), and the Paleozoic-Jurassic of the Western Desert (Egypt), as well as recent tidal dunes from the German coast of the North Sea and tidal cross-strata from the Devonian Koblentzquartzit (Federal Republic of Germany). In all cases the semi-elliptical bed-form model gave a good fit to the data, suggesting that it may be applicable over a wide range of bed forms. The data from the Western Desert could be explained only by data scatter due to channel sinuosity combined with the scatter attributed to the ellipticity of the bed-form crestlines.

  5. COMPUTATIONAL MODELING OF CIRCULATING FLUIDIZED BED REACTORS

    SciTech Connect (OSTI)

    Ibrahim, Essam A

    2013-01-09

    Details of numerical simulations of two-phase gas-solid turbulent flow in the riser section of Circulating Fluidized Bed Reactor (CFBR) using Computational Fluid Dynamics (CFD) technique are reported. Two CFBR riser configurations are considered and modeled. Each of these two riser models consist of inlet, exit, connecting elbows and a main pipe. Both riser configurations are cylindrical and have the same diameter but differ in their inlet lengths and main pipe height to enable investigation of riser geometrical scaling effects. In addition, two types of solid particles are exploited in the solid phase of the two-phase gas-solid riser flow simulations to study the influence of solid loading ratio on flow patterns. The gaseous phase in the two-phase flow is represented by standard atmospheric air. The CFD-based FLUENT software is employed to obtain steady state and transient solutions for flow modulations in the riser. The physical dimensions, types and numbers of computation meshes, and solution methodology utilized in the present work are stated. Flow parameters, such as static and dynamic pressure, species velocity, and volume fractions are monitored and analyzed. The differences in the computational results between the two models, under steady and transient conditions, are compared, contrasted, and discussed.

  6. MCNP4B Modeling of Pebble-Bed Reactors

    E-Print Network [OSTI]

    Lebenhaft, Julian Robert

    2001-10-15

    The applicability of the Monte Carlo code MCNP4B to the neutronic modeling of pebble-bed reactors was investigated. A modeling methodology was developed based on an analysis of critical experiments carried out at the ...

  7. The backflow cell model for fluidized bed catalytic reactors 

    E-Print Network [OSTI]

    Ganapathy, E. V

    1967-01-01

    that the backmixing of gas in a small fluidized bed with high length to diameter rati. o is relatively small. Hence, it was recommended. that reaction rate studies in fluidized bed reactors be correlated on the basis oi' piston flow~ neglecting mixing. Nay (19... Major Subject Chemical En ineerin THE BACKFLOW CELL MODEL FOR FLUIDIZED BED CATALYTIC REACTORS A Thesis E. V. Ganapathy Approved as to style and content by: chairman of Committee ~H+d d D p t t Member Member) May 1967 SO THE BACKFLOW CELL...

  8. Computational fluid dynamic modeling of fluidized-bed polymerization reactors

    SciTech Connect (OSTI)

    Rokkam, Ram

    2012-11-02

    Polyethylene is one of the most widely used plastics, and over 60 million tons are produced worldwide every year. Polyethylene is obtained by the catalytic polymerization of ethylene in gas and liquid phase reactors. The gas phase processes are more advantageous, and use fluidized-bed reactors for production of polyethylene. Since they operate so close to the melting point of the polymer, agglomeration is an operational concern in all slurry and gas polymerization processes. Electrostatics and hot spot formation are the main factors that contribute to agglomeration in gas-phase processes. Electrostatic charges in gas phase polymerization fluidized bed reactors are known to influence the bed hydrodynamics, particle elutriation, bubble size, bubble shape etc. Accumulation of electrostatic charges in the fluidized-bed can lead to operational issues. In this work a first-principles electrostatic model is developed and coupled with a multi-fluid computational fluid dynamic (CFD) model to understand the effect of electrostatics on the dynamics of a fluidized-bed. The multi-fluid CFD model for gas-particle flow is based on the kinetic theory of granular flows closures. The electrostatic model is developed based on a fixed, size-dependent charge for each type of particle (catalyst, polymer, polymer fines) phase. The combined CFD model is first verified using simple test cases, validated with experiments and applied to a pilot-scale polymerization fluidized-bed reactor. The CFD model reproduced qualitative trends in particle segregation and entrainment due to electrostatic charges observed in experiments. For the scale up of fluidized bed reactor, filtered models are developed and implemented on pilot scale reactor.

  9. Statistical surrogate models for prediction of high-consequence...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Statistical surrogate models for prediction of high-consequence climate change. Citation Details In-Document Search Title: Statistical surrogate models for...

  10. Emergent Behavior in a Low-Order Fluidized-Bed Bubble Model

    E-Print Network [OSTI]

    Tennessee, University of

    Emergent Behavior in a Low-Order Fluidized-Bed Bubble Model John S. Halow National Energy of this type of model to describe the dynamics of voids in bubbling fluidized beds. The model considers vertical interactions between neighboring bubbles in fluidized beds. Emergent collective behavior is shown

  11. Kinematic wave model for transient bed profiles in alluvial channels under nonequilibrium conditions 

    E-Print Network [OSTI]

    Tayfur, Gokmen; Singh, Vijay P.

    2007-12-27

    for transient bed profiles in alluvial channels under nonequilibrium conditions Gokmen Tayfur 1 and Vijay P. Singh 2 Received 31 October 2006; revised 22 May 2007; accepted 19 July 2007; published 27 December 2007. [1] Transient bed profiles in alluvial channels.... The model satisfactorily simulated transient bed forms observed in laboratory experiments. Citation: Tayfur, G., and V. P. Singh (2007), Kinematic wave model for transient bed profiles in alluvial channels under nonequilibrium conditions, Water Resour. Res...

  12. Modeling decadal bed material sediment flux based on stochastic Michael Bliss Singer and Thomas Dunne

    E-Print Network [OSTI]

    Singer, Michael

    Modeling decadal bed material sediment flux based on stochastic hydrology Michael Bliss Singer; published 18 March 2004. [1] Estimates of decadal bed material sediment flux and net storage are derived by driving sediment transport calculations with a stochastic hydrology model. The resulting estimates

  13. Modeling neuroscience patient flow and inpatient bed management

    E-Print Network [OSTI]

    Hiltrop, Jonas

    2014-01-01

    Massachusetts General Hospital (MGH) experiences consistently high demand for its more than 900 inpatient beds. On an average weekday, the hospital admits about 220 patients, with the emergency department (ED) and the ...

  14. 1 Copyright 2014 by ASME FLAMMABLE LIQUID FIRE CONSEQUENCE MODELING

    E-Print Network [OSTI]

    Barkan, Christopher P.L.

    The recent expansion in the production of shale petroleum crude oil, combined with the lack of new pipeline volumes of this commodity. Petroleum crude oil poses fire risk in the event of train accidents consequences, focusing on petroleum crude oil. A flow model using the spatial geographic information system

  15. LIQUID-FLUIDIZED-BED HEAT' EXCHANGER FLOW DISTRIBUTION MODELS

    Office of Scientific and Technical Information (OSTI)

    - OPERATIONS O F F I C E ABSTRACT Allied Chemical Corporation a t the Idaho National Engineering Labora- t o r y i s devel o p i n g 1 i q u i d-f 1 u i d i zed- bed she 1 1...

  16. Model-free adaptive control of supercritical circulating fluidized-bed boilers

    DOE Patents [OSTI]

    Cheng, George Shu-Xing; Mulkey, Steven L

    2014-12-16

    A novel 3-Input-3-Output (3.times.3) Fuel-Air Ratio Model-Free Adaptive (MFA) controller is introduced, which can effectively control key process variables including Bed Temperature, Excess O2, and Furnace Negative Pressure of combustion processes of advanced boilers. A novel 7-input-7-output (7.times.7) MFA control system is also described for controlling a combined 3-Input-3-Output (3.times.3) process of Boiler-Turbine-Generator (BTG) units and a 5.times.5 CFB combustion process of advanced boilers. Those boilers include Circulating Fluidized-Bed (CFB) Boilers and Once-Through Supercritical Circulating Fluidized-Bed (OTSC CFB) Boilers.

  17. Mechanical models of fracture reactivation and slip on bedding surfaces during folding of the asymmetric anticline at Sheep Mountain, Wyoming

    E-Print Network [OSTI]

    Borja, Ronaldo I.

    Mechanical models of fracture reactivation and slip on bedding surfaces during folding June 2008 Accepted 5 June 2008 Available online 13 June 2008 Keywords: Fold Fracture reactivation Bed methods to investigate the reactivation of fractures (opening and shearing) and the development of bedding

  18. Design report on SCDAP/RELAP5 model improvements - debris bed and molten pool behavior

    SciTech Connect (OSTI)

    Allison, C.M.; Rempe, J.L.; Chavez, S.A.

    1994-11-01

    the SCDAP/RELAP5/MOD3 computer code is designed to describe the overall reactor coolant system thermal-hydraulic response, core damage progression, and in combination with VICTORIA, fission product release and transport during severe accidents. Improvements for existing debris bed and molten pool models in the SCDAP/RELAP5/MOD3.1 code are described in this report. Model improvements to address (a) debris bed formation, heating, and melting; (b) molten pool formation and growth; and (c) molten pool crust failure are discussed. Relevant data, existing models, proposed modeling changes, and the anticipated impact of the changes are discussed. Recommendations for the assessment of improved models are provided.

  19. Assessment of effectiveness of geologic isolation systems. Test case release consequence analysis for a spent fuel repository in bedded salt

    SciTech Connect (OSTI)

    Raymond, J.R.; Bond, F.W.; Cole, C.R.; Nelson, R.W.; Reisenauer, A.E.; Washburn, J.F.; Norman, N.A.; Mote, P.A.; Segol, G.

    1980-01-01

    Geologic and geohydrologic data for the Paradox Basin have been used to simulate movement of ground water and radioacrtive contaminants from a hypothetical nuclear reactor spent fuel repository after an assumed accidental release. The pathlines, travel times and velocity of the ground water from the repository to the discharge locale (river) were determined after the disruptive event by use of a two-dimensional finite difference hydrologic model. The concentration of radioactive contaminants in the ground water was calculated along a series of flow tubes by use of a one-dimensional mass transport model which takes into account convection, dispersion, contaminant/media interactions and radioactive decay. For the hypothetical site location and specific parameters used in this demonstration, it is found that Iodine-129 (I-129) is tthe only isotope reaching the Colorado River in significant concentration. This concentration occurs about 8.0 x 10/sup 5/ years after the repository has been breached. This I-129 ground-water concentration is about 0.3 of the drinking water standard for uncontrolled use. The groundwater concentration would then be diluted by the Colorado River. None of the actinide elements reach more than half the distance from the repository to the Colorado River in the two-million year model run time. This exercise demonstrates that the WISAP model system is applicable for analysis of contaminant transport. The results presented in this report, however, are valid only for one particular set of parameters. A complete sensitivity analysis must be performed to evaluate the range of effects from the release of contaminants from a breached repository.

  20. A simplified model for the combustion of coal in a continuous flow fluidized bed 

    E-Print Network [OSTI]

    Richardson, Thomas Wade

    1982-01-01

    Calibration Numbers. 120 LIST OF FIGURES ~Fi ure ~Pa e 1 Modes of Fluidization. 2 Liquidlike Behavior of Fluidized Beds. 3 Continuous Reaction Model. 12 4 Shrinking Core Model 5 Two-Film Model. 6 Differential Control Volume. 13 14 34 7 Proximate... for approximating polynomial outside surface area (m ), (chapter 3 only) cross-sectional Area of the bed (cml), (chapter 4 only) surface area normal to the direction of heat flow (mt) boundary within which the element is defined frequency factor constant molar...

  1. A model for turbulent hydraulic fracture and application to crack propagation at glacier beds

    E-Print Network [OSTI]

    Tsai, Victor C.

    Click Here for Full Article A model for turbulent hydraulic fracture and application to crack suggest that fluidinduced hydraulic fracture of an ice sheet from its bed sometimes occurs quickly. Citation: Tsai, V. C., and J. R. Rice (2010), A model for turbulent hydraulic fracture and application

  2. ONE-DIMENSIONAL PSEUDO-HOMOGENEOUS PACKED BED REACTOR MODELING INCLUDING NO-CO KINETICS

    E-Print Network [OSTI]

    Srinivasan, Anand

    2011-08-31

    -homogeneous packed bed reactor model for this type of reactor setup built in collaboration with the Chemical and Petroleum Engineering Department at the University of Kansas. A brief summary of the pseudo-homogeneous model is presented in order to properly develop...

  3. Modeling Bed-Load Transport of Coarse Sediments in the Great Bay Estuary, New Hampshire.

    E-Print Network [OSTI]

    Modeling Bed-Load Transport of Coarse Sediments in the Great Bay Estuary, New Hampshire. A. Bilgili Hanover, NH 03755, U.S.A. 2 University of New Hampshire Ocean and Mechanical Engineering Departments River section of the Great Bay Estuary, New Hampshire, USA.- a well-mixed and geometrically complex

  4. Modeling for Anaerobic Fixed-Bed Biofilm Reactors

    SciTech Connect (OSTI)

    Liu, B. Y. M.; Pfeffer, J. T.

    1989-06-01

    The specific objectives of this research were: 1. to develop an equilibrium model for chemical aspects of anaerobic reactors; 2. to modify the equilibrium model for non-equilibrium conditions; 3. to incorporate the existing biofilm models into the models above to study the biological and chemical behavior of the fixed-film anaerobic reactors; 4. to experimentally verify the validity of these models; 5. to investigate the biomass-holding ability of difference packing materials for establishing reactor design criteria.

  5. MCNP4B modeling of pebble-bed reactors

    E-Print Network [OSTI]

    Lebenhaft, Julian R. (Julian Robert), 1954-

    2002-01-01

    The applicability of the Monte Carlo code MCNP4B to the neutronic modeling of pebblebed reactors was investigated. A modeling methodology was developed based on an analysis of critical experiments carried out at the ...

  6. Computational fluid dynamics modeling of coal gasification in a pressurized spout-fluid bed

    SciTech Connect (OSTI)

    Zhongyi Deng; Rui Xiao; Baosheng Jin; He Huang; Laihong Shen; Qilei Song; Qianjun Li [Southeast University, Nanjing (China). Key Laboratory of Clean Coal Power Generation and Combustion Technology of Ministry of Education

    2008-05-15

    Computational fluid dynamics (CFD) modeling, which has recently proven to be an effective means of analysis and optimization of energy-conversion processes, has been extended to coal gasification in this paper. A 3D mathematical model has been developed to simulate the coal gasification process in a pressurized spout-fluid bed. This CFD model is composed of gas-solid hydrodynamics, coal pyrolysis, char gasification, and gas phase reaction submodels. The rates of heterogeneous reactions are determined by combining Arrhenius rate and diffusion rate. The homogeneous reactions of gas phase can be treated as secondary reactions. A comparison of the calculated and experimental data shows that most gasification performance parameters can be predicted accurately. This good agreement indicates that CFD modeling can be used for complex fluidized beds coal gasification processes. 37 refs., 7 figs., 5 tabs.

  7. Wave-induced velocities inside a model seagrass bed

    E-Print Network [OSTI]

    Luhar, Mitul

    Laboratory measurements reveal the flow structure within and above a model seagrass meadow (dynamically similar to Zostera marina) forced by progressive waves. Despite being driven by purely oscillatory flow, a mean current ...

  8. Models to interpret bedform geometries from cross-bed data

    SciTech Connect (OSTI)

    Luthi, S.M. (Schlumberger-Doll Research, Ridgefield, CT (USA)); Banavar, J.R. (Pennsylvania State Univ., University Park (USA)); Bayer, U. (Kernforschungsanlage Juelich (West Germany))

    1990-03-01

    Semi-elliptical and sinusoidal bedform crestlines were modeled with curvature and sinuosity as parameters. Both bedform crestlines are propagated at various angles of migration over a finite area of deposition. Two computational approaches are used, a statistical random sampling (Monte Carlo) technique over the area of the deposit, and an analytical method based on topology and differential geometry. The resulting foreset azimuth distributions provide a catalogue for a variety of situations. The resulting thickness distributions have a simple shape and can be combined with the azimuth distributions to constrain further the cross-strata geometry. Paleocurrent directions obtained by these models can differ substantially from other methods, especially for obliquely migrating low-curvature bedforms. Interpretation of foreset azimuth data from outcrops and wells can be done either by visual comparison with the catalogued distributions, or by iterative computational fits. Studied examples include eolian cross-strata from the Permian Rotliegendes in the North Sea, fluvial dunes from the Devonian in the Catskills (New York State), the Triassic Schilfsandstein (West Germany) and the Paleozoic-Jurassic of the Western Desert (Egypt), as well as recent tidal dunes from the German coast of the North Sea and tidal cross-strata from the Devonian Koblentquartzit (West Germany). In all cases the semi-elliptical bedform model gave a good fit to the data, suggesting that it may be applicable over a wide range of bedforms. The data from the Western Desert could only be explained by data scatter due to channel sinuosity combining with the scatter attributed to the ellipticity of the bedform crestlines. These models, therefore, may also allow simulations of some hierarchically structured bedforms.

  9. Size exclusion deep bed filtration: Experimental and modelling uncertainties

    SciTech Connect (OSTI)

    Badalyan, Alexander You, Zhenjiang; Aji, Kaiser; Bedrikovetsky, Pavel; Carageorgos, Themis; Zeinijahromi, Abbas

    2014-01-15

    A detailed uncertainty analysis associated with carboxyl-modified latex particle capture in glass bead-formed porous media enabled verification of the two theoretical stochastic models for prediction of particle retention due to size exclusion. At the beginning of this analysis it is established that size exclusion is a dominant particle capture mechanism in the present study: calculated significant repulsive Derjaguin-Landau-Verwey-Overbeek potential between latex particles and glass beads is an indication of their mutual repulsion, thus, fulfilling the necessary condition for size exclusion. Applying linear uncertainty propagation method in the form of truncated Taylor's series expansion, combined standard uncertainties (CSUs) in normalised suspended particle concentrations are calculated using CSUs in experimentally determined parameters such as: an inlet volumetric flowrate of suspension, particle number in suspensions, particle concentrations in inlet and outlet streams, particle and pore throat size distributions. Weathering of glass beads in high alkaline solutions does not appreciably change particle size distribution, and, therefore, is not considered as an additional contributor to the weighted mean particle radius and corresponded weighted mean standard deviation. Weighted mean particle radius and LogNormal mean pore throat radius are characterised by the highest CSUs among all experimental parameters translating to high CSU in the jamming ratio factor (dimensionless particle size). Normalised suspended particle concentrations calculated via two theoretical models are characterised by higher CSUs than those for experimental data. The model accounting the fraction of inaccessible flow as a function of latex particle radius excellently predicts normalised suspended particle concentrations for the whole range of jamming ratios. The presented uncertainty analysis can be also used for comparison of intra- and inter-laboratory particle size exclusion data.

  10. A One-Dimensional (1-D) Three-Region Model for a Bubbling Fluidized-Bed Adsorber

    SciTech Connect (OSTI)

    Lee, Andrew; Miller, David C.

    2012-01-01

    A general one-dimensional (1-D), three-region model for a bubbling fluidized-bed adsorber with internal heat exchangers has been developed. The model can predict the hydrodynamics of the bed and provides axial profiles for all temperatures, concentrations, and velocities. The model is computationally fast and flexible and allows for any system of adsorption and desorption reactions to be modeled, making the model applicable to any adsorption process. The model has been implemented in both gPROMS and Aspen Custom Modeler, and the behavior of the model has been verified.

  11. Assessment of Drag Models for Geldart A Particles in Bubbling Fluidized Beds

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Estejab, Bahareh; Battaglia, Francine

    2015-10-08

    In order to accurately predict the hydrodynamic behavior of gas and solid phases using an Eulerian–Eulerian approach, it is crucial to use appropriate drag models to capture the correct physics. In this study, the performance of seven drag models for fluidization of Geldart A particles of coal, poplar wood, and their mixtures was assessed. In spite of the previous findings that bode badly for using predominately Geldart B drag models for fine particles, the results of our study revealed that if static regions of mass in the fluidized beds are considered, these drag models work well with Geldart A particles.more »It was found that drag models derived from empirical relationships adopt better with Geldart A particles compared to drag models that were numerically developed. Overall, the Huilin–Gidaspow drag model showed the best performance for both single solid phases and binary mixtures, however, for binary mixtures, Wen–Yu model predictions were also accurate.« less

  12. Modeling and Experimental Studies of Mercury Oxidation and Adsorption in a Fixed-Bed Reactor

    SciTech Connect (OSTI)

    Paula A. Buitrago, Mike Morrill, JoAnn S. Lighty, Geoffrey D.; Silcox,

    2009-06-15

    This report presents experimental and modeling mercury oxidation and adsorption data. Fixed-bed and single-particle models of mercury adsorption were developed. The experimental data were obtained with two reactors: a 300- W, methane-fired, tubular, quartz-lined reactor for studying homogeneous oxidation reactions and a fixed-bed reactor, also of quartz, for studying heterogeneous reactions. The latter was attached to the exit of the former to provide realistic combustion gases. The fixed-bed reactor contained one gram of coconut-shell carbon and remained at a temperature of 150oC. All methane, air, SO2, and halogen species were introduced through the burner to produce a radical pool representative of real combustion systems. A Tekran 2537A Analyzer coupled with a wet conditioning system provided speciated mercury concentrations. At 150°C and in the absence of HCl or HBr, the mercury uptake was about 20%. The addition of 50 ppm HCl caused complete capture of all elemental and oxidized mercury species. In the absence of halogens, SO2 increased the mercury adsorption efficiency to up to 30 percent. The extent of adsorption decreased with increasing SO2 concentration when halogens were present. Increasing the HCl concentration to 100 ppm lessened the effect of SO2. The fixed-bed model incorporates Langmuir adsorption kinetics and was developed to predict adsorption of elemental mercury and the effect of multiple flue gas components. This model neglects intraparticle diffusional resistances and is only applicable to pulverized carbon sorbents. It roughly describes experimental data from the literature. The current version includes the ability to account for competitive adsorption between mercury, SO2, and NO2. The single particle model simulates in-flight sorbent capture of elemental mercury. This model was developed to include Langmuir and Freundlich isotherms, rate equations, sorbent feed rate, and intraparticle diffusion. The Freundlich isotherm more accurately described in-flight mercury capture. Using these parameters, very little intraparticle diffusion was evident. Consistent with other data, smaller particles resulted in higher mercury uptake due to available surface area. Therefore, it is important to capture the particle size distribution in the model. At typical full-scale sorbent feed rates, the calculations underpredicted adsorption, suggesting that wall effects can account for as much as 50 percent of the removal, making it an important factor in entrained-mercury adsorption models.

  13. Predictive models of circulating fluidized bed combustors. 12th technical progress report

    SciTech Connect (OSTI)

    Gidaspow, D.

    1992-07-01

    Steady flows influenced by walls cannot be described by inviscid models. Flows in circulating fluidized beds have significant wall effects. Particles in the form of clusters or layers can be seen to run down the walls. Hence modeling of circulating fluidized beds (CFB) without a viscosity is not possible. However, in interpreting Equations (8-1) and (8-2) it must be kept in mind that CFB or most other two phase flows are never in a true steady state. Then the viscosity in Equations (8-1) and (8-2) may not be the true fluid viscosity to be discussed next, but an Eddy type viscosity caused by two phase flow oscillations usually referred to as turbulence. In view of the transient nature of two-phase flow, the drag and the boundary layer thickness may not be proportional to the square root of the intrinsic viscosity but depend upon it to a much smaller extent. As another example, liquid-solid flow and settling of colloidal particles in a lamella electrosettler the settling process is only moderately affected by viscosity. Inviscid flow with settling is a good first approximation to this electric field driven process. The physical meaning of the particulate phase viscosity is described in detail in the chapter on kinetic theory. Here the conventional derivation resented in single phase fluid mechanics is generalized to multiphase flow.

  14. Model-Theoretic Investigations into Consequence Operation (Cn) in Quantum Logics. An Algebraic Approach

    E-Print Network [OSTI]

    Piotr Wilczek

    2009-02-21

    In this paper we present the fundamentals of the so-called algebraic approach to propositional quantum logics. We define the set of formulas describing quantum reality as a free algebra freely generated by the set of quantum propositional variables. We define the general notion of logic as a structural consequence operation. Next we introduce the concept of logical matrices understood as a models of quantum logics. We give the definitions of two quantum consequence operations defined in these models.

  15. Limitations on fluid grid sizing for using volume-averaged fluid equations in discrete element models of fluidized beds

    E-Print Network [OSTI]

    Boyce, Christopher M.; Holland, Daniel; Dennis, John S.; Scott, Stuart A.

    2015-10-13

    Bubbling and slugging fluidization were simulated in 3D cylindrical fluidized beds using a discrete element model with computational fluid dynamics (DEM-CFD). A CFD grid was used in which the volume of all fluid cells was equal. Ninety simulations...

  16. Modeling the influence of river rehabilitation scenarios on bed material sediment flux in a large river over decadal timescales

    E-Print Network [OSTI]

    Singer, Michael

    Modeling the influence of river rehabilitation scenarios on bed material sediment flux in a large and calibrated sediment transport formulae were used to assess the decadal impact of major river rehabilitation the implementation of three major river rehabilitation strategies being considered in the Sacramento River Valley

  17. Modelling of Particle Pyrolysis in a Packed Bed Combustor A.R.C. Tuck and W.L.H. Hallett ,1 2*

    E-Print Network [OSTI]

    Hallett, William L.H.

    Modelling of Particle Pyrolysis in a Packed Bed Combustor A.R.C. Tuck and W.L.H. Hallett ,1 2 are accounted for [2]. However, initial efforts to include pyrolysis were quite crude: a simple one-step global presented here is therefore to upgrade the current treatment of pyrolysis in the bed by developing a more

  18. Empirical models of emissions and energy efficiencies of coal-fired fluidized bed power plants

    E-Print Network [OSTI]

    Gruhl, Jim

    Mass and energy balances of fluidized bed energy technologies are to a significant degree dependent upon the specific design being investigated. It is difficult to make any generally accurate comments. about these balances. ...

  19. Modeling of char oxidation in fluidized bed biomass gasifiers : effects of transport and chemical kinetics

    E-Print Network [OSTI]

    Brooks, Amelia (Amelia Samek)

    2015-01-01

    Technologies for the conversion of biomass to liquid fuels are important to develop because the demand for liquid fuels remains unchanged even with the necessity of limiting dependence on fossil fuels. Fluidized Bed Biomass ...

  20. Laboratory Experiments and Hydrodynamic Modeling of a Bed Leveler Used to Level the Bottom of Ship Channels after Dredging 

    E-Print Network [OSTI]

    Paul, Ephraim Udo

    2011-02-22

    This study was conducted to ascertain the impacts of bed leveling, following ship channel dredging operations, and to also investigate the hydrodynamic flow field around box bed levelers. Laboratory experiments were conducted with bed levelers...

  1. Thermo-mechanical Modelling of Pebble Beds in Fusion Blankets and its Implementation by a Return-Mapping Algorithm

    SciTech Connect (OSTI)

    Gan, Yixiang; Kamlah, Marc

    2008-07-01

    In this investigation, a thermo-mechanical model of pebble beds is adopted and developed based on experiments by Dr. Reimann at Forschungszentrum Karlsruhe (FZK). The framework of the present material model is composed of a non-linear elastic law, the Drucker-Prager-Cap theory, and a modified creep law. Furthermore, the volumetric inelastic strain dependent thermal conductivity of beryllium pebble beds is taken into account and full thermo-mechanical coupling is considered. Investigation showed that the Drucker-Prager-Cap model implemented in ABAQUS can not fulfill the requirements of both the prediction of large creep strains and the hardening behaviour caused by creep, which are of importance with respect to the application of pebble beds in fusion blankets. Therefore, UMAT (user defined material's mechanical behaviour) and UMATHT (user defined material's thermal behaviour) routines are used to re-implement the present thermo-mechanical model in ABAQUS. An elastic predictor radial return mapping algorithm is used to solve the non-associated plasticity iteratively, and a proper tangent stiffness matrix is obtained for cost-efficiency in the calculation. An explicit creep mechanism is adopted for the prediction of time-dependent behaviour in order to represent large creep strains in high temperature. Finally, the thermo-mechanical interactions are implemented in a UMATHT routine for the coupled analysis. The oedometric compression tests and creep tests of pebble beds at different temperatures are simulated with the help of the present UMAT and UMATHT routines, and the comparison between the simulation and the experiments is made. (authors)

  2. Evaluation of models for the prediction of fluidized-bed reactor performance 

    E-Print Network [OSTI]

    Frederick, John Michael

    1980-01-01

    of typical gas bubble L4] Fig. 8 Sketch of two bubbles coalescing in a fluidized bed L4] presence of splitting, the coalescence quality tends to produce a wide d1stribution of bubble sizes throughout the reactor. A parameter has been dev1sed that 1s... reactor Modes of fluidizaiton Geldhart's classification of fluidized bed particles . Distributors commonly used in industry Stages of bubble formation Idealised jet-to-bubble emergance pattern Sketch of a typical gas bubble ~Pa e 13 18 Sketch...

  3. A coupled transport and solid mechanics formulation with improved reaction kinetics parameters for modeling oxidation and decomposition in a uranium hydride bed.

    SciTech Connect (OSTI)

    Salloum, Maher N.; Shugard, Andrew D.; Kanouff, Michael P.; Gharagozloo, Patricia E.

    2013-03-01

    Modeling of reacting flows in porous media has become particularly important with the increased interest in hydrogen solid-storage beds. An advanced type of storage bed has been proposed that utilizes oxidation of uranium hydride to heat and decompose the hydride, releasing the hydrogen. To reduce the cost and time required to develop these systems experimentally, a valid computational model is required that simulates the reaction of uranium hydride and oxygen gas in a hydrogen storage bed using multiphysics finite element modeling. This SAND report discusses the advancements made in FY12 (since our last SAND report SAND2011-6939) to the model developed as a part of an ASC-P&EM project to address the shortcomings of the previous model. The model considers chemical reactions, heat transport, and mass transport within a hydride bed. Previously, the time-varying permeability and porosity were considered uniform. This led to discrepancies between the simulated results and experimental measurements. In this work, the effects of non-uniform changes in permeability and porosity due to phase and thermal expansion are accounted for. These expansions result in mechanical stresses that lead to bed deformation. To describe this, a simplified solid mechanics model for the local variation of permeability and porosity as a function of the local bed deformation is developed. By using this solid mechanics model, the agreement between our reacting bed model and the experimental data is improved. Additionally, more accurate uranium hydride oxidation kinetics parameters are obtained by fitting the experimental results from a pure uranium hydride oxidation measurement to the ones obtained from the coupled transport-solid mechanics model. Finally, the coupled transport-solid mechanics model governing equations and boundary conditions are summarized and recommendations are made for further development of ARIA and other Sandia codes in order for them to sufficiently implement the model.

  4. Modeling and Experimental Studies of Mercury Oxidation and Adsorption in a Fixed-Bed and Entrained-Flow Reactor

    SciTech Connect (OSTI)

    Buitrago, Paula A; Morrill, Mike; Lighty, JoAnn S; Silcox, Geoffrey D

    2014-08-20

    This report presents experimental and modeling mercury oxidation and adsorption data. Fixed-bed and single-particle models of mercury adsorption were developed. The experimental data were obtained with two reactors: a 300-W, methane-fired, tubular, quartz-lined reactor for studying homogeneous oxidation reactions and a fixed-bed reactor, also of quartz, for studying heterogeneous reactions. The latter was attached to the exit of the former to provide realistic combustion gases. The fixed-bed reactor contained one gram of coconut-shell carbon and remained at a temperature of 150oC. All methane, air, SO2, and halogen species were introduced through the burner to produce a radical pool representative of real combustion systems. A Tekran 2537A Analyzer coupled with a wet conditioning system provided speciated mercury concentrations. At 150?C and in the absence of HCl or HBr, the mercury uptake was about 20%. The addition of 50 ppm HCl caused complete capture of all elemental and oxidized mercury species. In the absence of halogens, SO2 increased the mercury adsorption efficiency to up to 30 percent. The extent of adsorption decreased with increasing SO2 concentration when halogens were present. Increasing the HCl concentration to 100 ppm lessened the effect of SO2. The fixed-bed model incorporates Langmuir adsorption kinetics and was developed to predict adsorption of elemental mercury and the effect of multiple flue gas components. This model neglects intraparticle diffusional resistances and is only applicable to pulverized carbon sorbents. It roughly describes experimental data from the literature. The current version includes the ability to account for competitive adsorption between mercury, SO2, and NO2. The single particle model simulates in-flight sorbent capture of elemental mercury. This model was developed to include Langmuir and Freundlich isotherms, rate equations, sorbent feed rate, and intraparticle diffusion. The Freundlich isotherm more accurately described in-flight mercury capture. Using these parameters, very little intraparticle diffusion was evident. Consistent with other data, smaller particles resulted in higher mercury uptake due to available surface area. Therefore, it is important to capture the particle size distribution in the model. At typical full-scale sorbent feed rates, the calculations underpredicted adsorption, suggesting that wall effects can account for as much as 50 percent of the removal, making it an important factor in entrained-mercury adsorption models.

  5. A mathematical model for countercurrent moving-bed activated carbon adsorption 

    E-Print Network [OSTI]

    Anderson, Douglas Harold

    1976-01-01

    effluent from a wastewater treatment plant. CHAPTER II LITERATURE REVIEW Activated carbon removes substances from water by adsorption, which is the physical attachment of a mole- cule to a surface. The attractive forces are van der Waal's forces... treatment. Among these are: 1. Capable of removing organic contamination to minimal concentration; 2. No additional disposal or pollutional problems are created; 3. Excess capacity in the carbon beds can effec- tively process unexpected impurity...

  6. Modeling the resolution of inexpensive, novel non-seismic geophysical monitoring tools to monitor CO2 injection into coal beds

    E-Print Network [OSTI]

    Gasperikova, E.

    2010-01-01

    Plasynski, S. , 2008, Advancing Coal-Based Power Generationto monitor CO 2 injection into Coal Beds as a part of theanalysis for CO 2 movement in coal beds was based on the

  7. Bed topography and the development of forced bed surface patches

    E-Print Network [OSTI]

    Venditti, Jeremy G.

    stress field, calculated from velocity measurements and with a quasithreedimensional hydraulic model (Fa which we made measurements of local nearbed velocity and sediment transport. The bed developedSTMECH), displayed substantial variability across the bar unit. Bed surface grain size did not correlate with local

  8. Bed Bugs 

    E-Print Network [OSTI]

    Gold, Roger E.; Howell Jr., Harry N.

    2001-11-15

    stream_source_info pdf_1512.pdf.txt stream_content_type text/plain stream_size 5811 Content-Encoding ISO-8859-1 stream_name pdf_1512.pdf.txt Content-Type text/plain; charset=ISO-8859-1 Bed Bugs L-1742 9-01 Roger Gold...

  9. Uncertainty and sensitivity analysis of early exposure results with the MACCS Reactor Accident Consequence Model

    SciTech Connect (OSTI)

    Helton, J.C.; Johnson, J.D.; McKay, M.D.; Shiver, A.W.; Sprung, J.L.

    1995-01-01

    Uncertainty and sensitivity analysis techniques based on Latin hypercube sampling, partial correlation analysis and stepwise regression analysis are used in an investigation with the MACCS model of the early health effects associated with a severe accident at a nuclear power station. The primary purpose of this study is to provide guidance on the variables to be considered in future review work to reduce the uncertainty in the important variables used in the calculation of reactor accident consequences. The effects of 34 imprecisely known input variables on the following reactor accident consequences are studied: number of early fatalities, number of cases of prodromal vomiting, population dose within 10 mi of the reactor, population dose within 1000 mi of the reactor, individual early fatality probability within 1 mi of the reactor, and maximum early fatality distance. When the predicted variables are considered collectively, the following input variables were found to be the dominant contributors to uncertainty: scaling factor for horizontal dispersion, dry deposition velocity, inhalation protection factor for nonevacuees, groundshine shielding factor for nonevacuees, early fatality hazard function alpha value for bone marrow exposure, and scaling factor for vertical dispersion.

  10. Surety of human elements of high consequence systems: An organic model

    SciTech Connect (OSTI)

    FORSYTHE,JAMES C.; WENNER,CAREN A.

    2000-04-25

    Despite extensive safety analysis and application of safety measures, there is a frequent lament, ``Why do we continue to have accidents?'' Two breakdowns are prevalent in risk management and prevention. First, accidents result from human actions that engineers, analysts and management never envisioned and second, controls, intended to preclude/mitigate accident sequences, prove inadequate. This paper addresses the first breakdown, the inability to anticipate scenarios involving human action/inaction. The failure of controls has been addressed in a previous publication (Forsythe and Grose, 1998). Specifically, this paper presents an approach referred to as surety. The objective of this approach is to provide high levels of assurance in situations where potential system failure paths cannot be fully characterized. With regard to human elements of complex systems, traditional approaches to human reliability are not sufficient to attain surety. Consequently, an Organic Model has been developed to account for the organic properties exhibited by engineered systems that result from human involvement in those systems.

  11. SOFTWARE QUALITY ASSURANCE FOR EMERGENCY RESPONSE CONSEQUENCE ASSESSMENT MODELS AT DOE'S SAVANNAH RIVER SITE

    SciTech Connect (OSTI)

    Hunter, C

    2007-12-17

    The Savannah River National Laboratory's (SRNL) Atmospheric Technologies Group develops, maintains, and operates computer-based software applications for use in emergency response consequence assessment at DOE's Savannah River Site. These applications range from straightforward, stand-alone Gaussian dispersion models run with simple meteorological input to complex computational software systems with supporting scripts that simulate highly dynamic atmospheric processes. A software quality assurance program has been developed to ensure appropriate lifecycle management of these software applications. This program was designed to meet fully the overall structure and intent of SRNL's institutional software QA programs, yet remain sufficiently practical to achieve the necessary level of control in a cost-effective manner. A general overview of this program is described.

  12. Intrashelf basins: A geologic model for source-bed and reservoir facies deposition within carbonate shelves

    SciTech Connect (OSTI)

    Grover, G. Jr. (Sauid Aramco, Dhahran (Saudi Arabia))

    1993-09-01

    Intrashelf basins (moats, inshore basins, shelf basins, differentiated shelf, and deep-water lagoons of others) are depressions of varying sizes and shapes that occur within tectonically passive and regionally extensive carbonate shelves. Intrashelf basins grade laterally and downdip (seaward) into shallow-water carbonates of the regional shelf, are separated from the open marine basin by the shelf margin, and are largely filled by fine-grained subtidal sediments having attributes of shallow- and deeper water sedimentation. These basins are commonly fringed or overlain by carbonate sands, reefs, or buildups. These facies may mimic those that occur along the regional shelf margin, and they can have trends that are at a high angle to that of the regional shelf. Intrashelf basins are not intracratonic basins. The history of most intrashelf basins is a few million to a few tens of million of years. Examples of intrashelf basins are known throughout the Phanerozoic; the southern portion of the Holocene Belize shelf is a modern example of an intrashelf basin. Two types of intrashelf basins are recognized. Coastal basins pass updip into coastal clastics of the craton with the basin primarily filled by fine clastics. Shelf basins occur on the outer part of the shelf, are surrounded by shallow-water carbonate facies, and are filled by peloidal lime mud, pelagics, and argillaceous carbonates. Intrashelf basins are commonly the site of organic-rich, source-bed deposition, resulting in the close proximity of source beds and reservoir facies that may fringe or overlie the basin. Examples of hydrocarbon-charged reservoirs that were sourced by an intrashelf basin include the Miocene Bombay High field, offshore India; the giant Jurassic (Arab-D) and Cretaceous (Shuaiba) reservoirs of the Arabian Shelf; the Lower Cretaceous Sunniland trend, South Florida basin; and the Permian-Pennsylvanian reservoirs surrounding the Tatum basin in southeastern New Mexico.

  13. Biomass Torrefaction Process Review and Moving Bed Torrefaction System Model Development

    SciTech Connect (OSTI)

    Jaya Shakar Tumuluru; Shahab Sokhansanj; Christopher T. Wright; Richard D. Boardman

    2010-08-01

    Torrefaction is currently developing as an important preprocessing step to improve the quality of biomass in terms of physical properties, and proximate and ultimate composition. Torrefaction is a slow heating of biomass in an inert or reduced environment to a maximum temperature of 300 C. Torrefaction can also be defined as a group of products resulting from the partially controlled and isothermal pyrolysis of biomass occurring in a temperature range of 200-230 C and 270-280 C. Thus, the process can also be called a mild pyrolysis as it occurs at the lower temperature range of the pyrolysis process. At the end of the torrefaction process, a solid uniform product with lower moisture content and higher energy content than raw biomass is produced. Most of the smoke-producing compounds and other volatiles are removed during torrefaction, producing a final product that will have a lower mass but a higher heating value. An important aspect of research is to establish a degree of torrefaction where gains in heating value offset the loss of mass. There is a lack of literature on torrefaction reactor designs and a design sheet for estimating the dimensions of the torrefier based on capacity. This study includes (a) conducting a detailed review on the torrefaction of biomass in terms of understanding the process, product properties, off-gas compositions, and methods used, and (b) to design a moving bed torrefier, taking into account the basic fundamental heat and mass transfer calculations. Specific objectives include calculating the dimensions like diameter and height of the moving packed bed for different capacities, designing the heat loads and gas flow rates, and developing an interactive excel sheet where the user can define design specifications. In this report, 25-1000 kg/hr are used in equations for the design of the torrefier, examples of calculations, and specifications for the torrefier.

  14. Biomass Torrefaction Process Review and Moving Bed Torrefaction System Model Development

    SciTech Connect (OSTI)

    Jaya Shakar Tumuluru; Shahab Sokhansanj; Christopher T. Wright

    2010-08-01

    Torrefaction is currently developing as an important preprocessing step to improve the quality of biomass in terms of physical properties, and proximate and ultimate composition. Torrefaction is a slow heating of biomass in an inert or reduced environment to a maximum temperature of 300°C. Torrefaction can also be defined as a group of products resulting from the partially controlled and isothermal pyrolysis of biomass occurring in a temperature range of 200–230şC and 270–280şC. Thus, the process can also be called a mild pyrolysis as it occurs at the lower temperature range of the pyrolysis process. At the end of the torrefaction process, a solid uniform product with lower moisture content and higher energy content than raw biomass is produced. Most of the smoke-producing compounds and other volatiles are removed during torrefaction, producing a final product that will have a lower mass but a higher heating value. An important aspect of research is to establish a degree of torrefaction where gains in heating value offset the loss of mass. There is a lack of literature on torrefaction reactor designs and a design sheet for estimating the dimensions of the torrefier based on capacity. This study includes a) conducting a detailed review on the torrefaction of biomass in terms of understanding the process, product properties, off-gas compositions, and methods used, and b) to design a moving bed torrefier, taking into account the basic fundamental heat and mass transfer calculations. Specific objectives include calculating the dimensions like diameter and height of the moving packed bed for different capacities, designing the heat loads and gas flow rates, and developing an interactive excel sheet where the user can define design specifications. In this report, 25–1000 kg/hr are used in equations for the design of the torrefier, examples of calculations, and specifications for the torrefier.

  15. Uncertainty and sensitivity analysis of food pathway results with the MACCS Reactor Accident Consequence Model

    SciTech Connect (OSTI)

    Helton, J.C.; Johnson, J.D.; Rollstin, J.A.; Shiver, A.W.; Sprung, J.L.

    1995-01-01

    Uncertainty and sensitivity analysis techniques based on Latin hypercube sampling, partial correlation analysis and stepwise regression analysis are used in an investigation with the MACCS model of the food pathways associated with a severe accident at a nuclear power station. The primary purpose of this study is to provide guidance on the variables to be considered in future review work to reduce the uncertainty in the important variables used in the calculation of reactor accident consequences. The effects of 87 imprecisely-known input variables on the following reactor accident consequences are studied: crop growing season dose, crop long-term dose, milk growing season dose, total food pathways dose, total ingestion pathways dose, total long-term pathways dose, area dependent cost, crop disposal cost, milk disposal cost, condemnation area, crop disposal area and milk disposal area. When the predicted variables are considered collectively, the following input variables were found to be the dominant contributors to uncertainty: fraction of cesium deposition on grain fields that is retained on plant surfaces and transferred directly to grain, maximum allowable ground concentrations of Cs-137 and Sr-90 for production of crops, ground concentrations of Cs-134, Cs-137 and I-131 at which the disposal of milk will be initiated due to accidents that occur during the growing season, ground concentrations of Cs-134, I-131 and Sr-90 at which the disposal of crops will be initiated due to accidents that occur during the growing season, rate of depletion of Cs-137 and Sr-90 from the root zone, transfer of Sr-90 from soil to legumes, transfer of Cs-137 from soil to pasture, transfer of cesium from animal feed to meat, and the transfer of cesium, iodine and strontium from animal feed to milk.

  16. Uncertainty and sensitivity analysis of chronic exposure results with the MACCS reactor accident consequence model

    SciTech Connect (OSTI)

    Helton, J.C.; Johnson, J.D.; Rollstin, J.A.; Shiver, A.W.; Sprung, J.L.

    1995-01-01

    Uncertainty and sensitivity analysis techniques based on Latin hypercube sampling, partial correlation analysis and stepwise regression analysis are used in an investigation with the MACCS model of the chronic exposure pathways associated with a severe accident at a nuclear power station. The primary purpose of this study is to provide guidance on the variables to be considered in future review work to reduce the uncertainty in the important variables used in the calculation of reactor accident consequences. The effects of 75 imprecisely known input variables on the following reactor accident consequences are studied: crop growing season dose, crop long-term dose, water ingestion dose, milk growing season dose, long-term groundshine dose, long-term inhalation dose, total food pathways dose, total ingestion pathways dose, total long-term pathways dose, total latent cancer fatalities, area-dependent cost, crop disposal cost, milk disposal cost, population-dependent cost, total economic cost, condemnation area, condemnation population, crop disposal area and milk disposal area. When the predicted variables are considered collectively, the following input variables were found to be the dominant contributors to uncertainty: dry deposition velocity, transfer of cesium from animal feed to milk, transfer of cesium from animal feed to meat, ground concentration of Cs-134 at which the disposal of milk products will be initiated, transfer of Sr-90 from soil to legumes, maximum allowable ground concentration of Sr-90 for production of crops, fraction of cesium entering surface water that is consumed in drinking water, groundshine shielding factor, scale factor defining resuspension, dose reduction associated with decontamination, and ground concentration of 1-131 at which disposal of crops will be initiated due to accidents that occur during the growing season.

  17. Formal deduction of the Saint-Venant-Exner model including arbitrarily sloping sediment beds and associated energy

    E-Print Network [OSTI]

    Fernández-Nieto, E D; Narbona-Reina, G; Zabsonré, J D

    2015-01-01

    In this work we present a deduction of the Saint-Venant-Exner model through an asymptotic analysis of the Navier-Stokes equations. A multi-scale analysis is performed in order to take into account that the velocity of the sediment layer is smaller than the one of the fluid layer. This leads us to consider a shallow water type system for the fluid layer and a lubrication Reynolds equation for the sediment one. This deduction provides some improvements with respect to the classical Saint-Venant-Exner model: (i) the deduced model has an associated energy. Moreover, it allows us to explain why classical models do not have an associated energy and how to modify them in order to recover a model with this property. (ii) The model incorporates naturally a necessary modification that must be taken into account in order to be applied to arbitrarily sloping beds. Furthermore, we show that this modification is different of the ones considered classically, and that it coincides with a classical one only if the solution ha...

  18. Circulating Fluid Bed Combustor 

    E-Print Network [OSTI]

    Fraley, L. D.; Do, L. N.; Hsiao, K. H.

    1982-01-01

    The circulating bed combustor represents an alternative concept of burning coal in fluid bed technology, which offers distinct advantages over both the current conventional fluidized bed combustion system and the pulverized coal boilers equipped...

  19. Steady state and dynamic modeling of a packed bed reactor for the partial oxidation of methanol to formaldehyde: experimental results compared with model predictions

    SciTech Connect (OSTI)

    Schwedock, M.J.; Windes, L.C.; Ray, W.H.

    1985-01-01

    Heterogeneous and pseudohomogeneous models are compared to experimental data from a packed bed reactor for the partical oxidation of methanol to formaldehyde over an iron oxide-molybdenum oxide catalyst. Heat transfer parameters which were successful in matching data from experiments without reaction were not successful in matching temperature data from experiments with reaction. This made it necessary to decrease the fluid radial heat transfer to obtain good fit. A good fit was obtained for steady state composition profiles by optimizing selected frequency factors and the activation energy for methanol. A redox rate expression for the oxidation of formaldehyde to carbon monoxide was proposed since a simple first-order rate expression did not fit the data. The pseudohomogeneous model gave results similar to the heterogeneous model for both steady state and dynamic experiments and has been recommended for future experimental state estimation and control studies. 21 refs., 31 figs., 6 tabs.

  20. A non-equilibrium model for fixed-bed multi-component adiabatic adsorption 

    E-Print Network [OSTI]

    Harwell, Jeffrey Harry

    1979-01-01

    , 1970, 1972b). The objectives ares 1, To develop a non-equilibrium model for multicomponent adiabatic adsorption and show the dynamic behavior of the dependent' variables Cia qi ~ Tg and Ts, 2. Examine the validity of the assumption of local... mass of. solid, respec- tively, Qi is the saturation value of qi for component i, It depends on the surface ares occupied by one molecule of i and:W -hence independent of temperature. Ki is the zeciprocai of Ci when half the suz'face is oc- cupied...

  1. Hybrid fluidized bed combuster

    DOE Patents [OSTI]

    Kantesaria, Prabhudas P. (Windsor, CT); Matthews, Francis T. (Poquonock, CT)

    1982-01-01

    A first atmospheric bubbling fluidized bed furnace is combined with a second turbulent, circulating fluidized bed furnace to produce heat efficiently from crushed solid fuel. The bed of the second furnace receives the smaller sizes of crushed solid fuel, unreacted limestone from the first bed, and elutriated solids extracted from the flu gases of the first bed. The two-stage combustion of crushed solid fuel provides a system with an efficiency greater than available with use of a single furnace of a fluidized bed.

  2. Dynamic Modeling and Control Studies of a Two-Stage Bubbling Fluidized Bed Adsorber-Reactor for Solid-Sorbent CO{sub 2} Capture

    SciTech Connect (OSTI)

    Modekurti, Srinivasarao; Bhattacharyya, Debangsu; Zitney, Stephen E.

    2013-07-31

    A one-dimensional, non-isothermal, pressure-driven dynamic model has been developed for a two-stage bubbling fluidized bed (BFB) adsorber-reactor for solid-sorbent carbon dioxide (CO{sub 2}) capture using Aspen Custom Modeler® (ACM). The BFB model for the flow of gas through a continuous phase of downward moving solids considers three regions: emulsion, bubble, and cloud-wake. Both the upper and lower reactor stages are of overflow-type configuration, i.e., the solids leave from the top of each stage. In addition, dynamic models have been developed for the downcomer that transfers solids between the stages and the exit hopper that removes solids from the bottom of the bed. The models of all auxiliary equipment such as valves and gas distributor have been integrated with the main model of the two-stage adsorber reactor. Using the developed dynamic model, the transient responses of various process variables such as CO{sub 2} capture rate and flue gas outlet temperatures have been studied by simulating typical disturbances such as change in the temperature, flowrate, and composition of the incoming flue gas from pulverized coal-fired power plants. In control studies, the performance of a proportional-integral-derivative (PID) controller, feedback-augmented feedforward controller, and linear model predictive controller (LMPC) are evaluated for maintaining the overall CO{sub 2} capture rate at a desired level in the face of typical disturbances.

  3. Nuclear winter revisited with a modern climate model and current nuclear arsenals: Still catastrophic consequences

    E-Print Network [OSTI]

    Robock, Alan

    Nuclear winter revisited with a modern climate model and current nuclear arsenals: Still of climate model simulations of the response to smoke and dust from a massive nuclear exchange between the superpowers could be summarized as ``nuclear winter,'' with rapid temperature, precipitation, and insolation

  4. Vacuum fluctuation inside a star and their consequences for neutron stars, a simple model

    E-Print Network [OSTI]

    Gunther Caspar; Isaac Rodriguez; Peter O. Hess; Walter Greiner

    2015-06-03

    Applying semi-classical Quantum Mechanics, the vacuum fluctuations within a star are determined, assuming a constant mass density and applying a monopole approximation. It is found that the density for the vacuum fluctuations does not only depend linearly on the mass density, as assumed in a former publication, where neutron stars up to 6 solar masses were obtained. This is used to propose a simple model on the dependence of the dark energy to the mass density, as a function of the radial distance r. It is shown that stars with up to 200 solar masses can, in principle, be obtained. Though, we use a simple model, it shows that in the presence of vacuum fluctuations stars with large masses can be stabilized and probably stars up to any mass can exist, which usually are identified as black holes.

  5. Particle pressures in fluidized beds. Final report

    SciTech Connect (OSTI)

    Campbell, C.S.; Rahman, K.; Jin, C.

    1996-09-01

    This project studies the particle pressure, which may be thought of as the force exerted by the particulate phase of a multiphase mixture, independently of that exerted by other phases. The project is divided into two parts, one concerning gas and the other liquid fluidized beds. Previous work on gas fluidized beds had suggested that the particle pressures are generated by bubbling action. Thus, for these gas fluidized bed studies, the particle pressure is measured around single bubbles generated in 2-D fluidized beds, using special probes developed especially for this purpose. Liquid beds are immune from bubbling and the particle pressures proved too small to measure directly. However, the major interest in particle pressures in liquid beds lies in their stabilizing effect that arises from the effective elasticity (the derivative of the particle pressure with respect to the void fraction), they impart to the bed. So rather than directly measure the particle pressure, the authors inferred the values of the elasticity from measurements of instability growth in liquid beds; the inference was made by first developing a generic stability model (one with all the normally modeled coefficients left undetermined) and then working backwards to determine the unknown coefficients, including the elasticity.

  6. Particle Pressures in Fluidized Beds. Final report

    SciTech Connect (OSTI)

    Campbell, C.S.; Rahman, K.; Jin, C.

    1996-09-01

    This project studies the particle pressure, which may be thought of as the force exerted by the particulate phase of a multiphase mixture, independently of that exerted by other phases. The project is divided into two parts, one concerning gas and the other liquid fluidized beds. Previous work on gas fluidized beds had suggested that the particle pressures are generated by bubbling action. Thus, for these gas fluidized bed studies, the particle pressure is measured around single bubbles generated in 2-D fluidized beds, using special probes developed especially for this purpose. Liquid beds are immune from bubbling and the particle pressures proved too small to measure directly. However, the major interest in particle pressures in liquid beds lies in their stabilizing effect that arises from the effective elasticity (the derivative of the particle pressure with respect to the void fraction): they impart to the bed. So rather than directly measure the particle pressure, we inferred the values of the elasticity from measurements of instability growth in liquid beds the inference was made by first developing a generic stability model (one with all the normally modeled coefficients left undetermined)and then working backwards to determine the unknown coefficients, including the elasticity.

  7. Health effects model for nuclear power plant accident consequence analysis. Part I. Introduction, integration, and summary. Part II. Scientific basis for health effects models

    SciTech Connect (OSTI)

    Evans, J.S.; Moeller, D.W.; Cooper, D.W.

    1985-07-01

    Analysis of the radiological health effects of nuclear power plant accidents requires models for predicting early health effects, cancers and benign thyroid nodules, and genetic effects. Since the publication of the Reactor Safety Study, additional information on radiological health effects has become available. This report summarizes the efforts of a program designed to provide revised health effects models for nuclear power plant accident consequence modeling. The new models for early effects address four causes of mortality and nine categories of morbidity. The models for early effects are based upon two parameter Weibull functions. They permit evaluation of the influence of dose protraction and address the issue of variation in radiosensitivity among the population. The piecewise-linear dose-response models used in the Reactor Safety Study to predict cancers and thyroid nodules have been replaced by linear and linear-quadratic models. The new models reflect the most recently reported results of the follow-up of the survivors of the bombings of Hiroshima and Nagasaki and permit analysis of both morbidity and mortality. The new models for genetic effects allow prediction of genetic risks in each of the first five generations after an accident and include information on the relative severity of various classes of genetic effects. The uncertainty in modeloling radiological health risks is addressed by providing central, upper, and lower estimates of risks. An approach is outlined for summarizing the health consequences of nuclear power plant accidents. 298 refs., 9 figs., 49 tabs.

  8. A PROTOTYPE FOUR INCH SHORT HYDRIDE (FISH) BED AS A REPLACEMENT TRITIUM STORAGE BED

    SciTech Connect (OSTI)

    Klein, J.; Estochen, E.; Shanahan, K.; Heung, L.

    2011-02-23

    The Savannah River Site (SRS) tritium facilities have used 1st generation (Gen1) metal hydride storage bed assemblies with process vessels (PVs) fabricated from 3 inch nominal pipe size (NPS) pipe to hold up to 12.6 kg of LaNi{sub 4.25}Al{sub 0.75} metal hydride for tritium gas absorption, storage, and desorption for over 15 years. The 2nd generation (Gen2) of the bed design used the same NPS for the PV, but the added internal components produced a bed nominally 1.2 m long, and presented a significant challenge for heater cartridge replacement in a footprint limited glove-box. A prototype 3rd generation (Gen3) metal hydride storage bed has been designed and fabricated as a replacement candidate for the Gen2 storage bed. The prototype Gen3 bed uses a PV pipe diameter of 4 inch NPS so the bed length can be reduced below 0.7 m to facilitate heater cartridge replacement. For the Gen3 prototype bed, modeling results show increased absorption rates when using hydrides with lower absorption pressures. To improve absorption performance compared to the Gen2 beds, a LaNi{sub 4.15}Al{sub 0.85} material was procured and processed to obtain the desired pressure-composition-temperature (PCT) properties. Other bed design improvements are also presented.

  9. Review on Biomass Torrefaction Process and Product Properties and Design of Moving Bed Torrefaction System Model Development

    SciTech Connect (OSTI)

    Jaya Shankar Tumuluru; Christopher T. Wright; Shahab Sokhansanj

    2011-08-01

    A Review on Torrefaction Process and Design of Moving Bed Torrefaction System for Biomass Processing Jaya Shankar Tumuluru1, Shahab Sokhansanj2 and Christopher T. Wright1 Idaho National Laboratory Biofuels and Renewable Energy Technologies Department Idaho Falls, Idaho 83415 Oak Ridge National Laboratory Bioenergy Resource and Engineering Systems Group Oak Ridge, TN 37831 Abstract Torrefaction is currently developing as an important preprocessing step to improve the quality of biomass in terms of physical properties, and proximate and ultimate composition. Torrefaction is a slow heating of biomass in an inert or reduced environment to a maximum temperature of 300 C. Torrefaction can also be defined as a group of products resulting from the partially controlled and isothermal pyrolysis of biomass occurring in a temperature range of 200-230 C and 270-280 C. Thus, the process can also be called a mild pyrolysis as it occurs at the lower temperature range of the pyrolysis process. At the end of the torrefaction process, a solid uniform product with lower moisture content and higher energy content than raw biomass is produced. Most of the smoke-producing compounds and other volatiles are removed during torrefaction, which produces a final product that will have a lower mass but a higher heating value. There is a lack of literature on the design aspects of torrefaction reactor and a design sheet for estimating the dimensions of the torrefier based on capacity. This study includes (a) conducting a detailed review on the torrefaction of biomass in terms of understanding the process, product properties, off-gas compositions, and methods used, and (b) to design a moving bed torrefier, taking into account the basic fundamental heat and mass transfer calculations. Specific objectives include calculating the dimensions like diameter and height of the moving packed bed torrefier for different capacities ranging from 25-1000 kg/hr, designing the heat loads and gas flow rates, and developing an interactive excel sheet where the user can define design specifications.

  10. Fluidized bed combustion

    SciTech Connect (OSTI)

    Sowards, N.K.; Murphy, M.L.

    1991-10-29

    This patent describes a vessel. It comprises a fluid bed for continuously incinerating fuel comprising tire segments and the like which comprise metallic wire tramp and for concurrently removing tramp and bed materials at a bottom effluent exit means of the vessel, the vessel further comprising static air distributor means at the periphery of the bed comprising a substantially centrally unobstructed relatively large central region in which the fluid bed and fuel only are disposed and through which bed material and tramp migrate without obstruction to and through the effluent exit means, downwardly and inwardly stepped lower vessel wall means and a plurality of peripherally located centrally directed vertically and horizontally offset spaced air influent means surrounding the central region and associated with the stepped lower vessel wall means by which the bed is supported and fluidized.

  11. Review of models used for determining consequences of UF{sub 6} release: Development of model evaluation criteria. Volume 1

    SciTech Connect (OSTI)

    Nair, S.K.; Chambers, D.B.; Park, S.H.; Hoffman, F.O. [Senes Oak Ridge, Inc., TN (United States). Center for Risk Analysis

    1997-11-01

    The objective of this study is to examine the usefulness and effectiveness of currently existing models that simulate the release of uranium hexafluoride from UF{sub 6}-handling facilities, subsequent reactions of UF{sub 6} with atmospheric moisture, and the dispersion of UF{sub 6} and reaction products in the atmosphere. The study evaluates screening-level and detailed public-domain models that were specifically developed for UF{sub 6} and models that were originally developed for the treatment of dense gases but are applicable to UF{sub 6} release, reaction, and dispersion. The model evaluation process is divided into three specific tasks: model-component evaluation; applicability evaluation; and user interface and quality assurance and quality control (QA/QC) evaluation. Within the model-component evaluation process, a model`s treatment of source term, thermodynamics, and atmospheric dispersion are considered and model predictions are compared with actual observations. Within the applicability evaluation process, a model`s applicability to Integrated Safety Analysis, Emergency Response Planning, and Post-Accident Analysis, and to site-specific considerations are assessed. Finally, within the user interface and QA/QC evaluation process, a model`s user-friendliness, presence and clarity of documentation, ease of use, etc. are assessed, along with its handling of QA/QC. This document presents the complete methodology used in the evaluation process.

  12. Review of models used for determining consequences of UF{sub 6} release: Model evaluation report. Volume 2

    SciTech Connect (OSTI)

    Nair, S.K.; Chambers, D.B.; Park, S.H.; Radonjic, Z.R.; Coutts, P.T.; Lewis, C.J.; Hammonds, J.S.; Hoffman, F.O. [Senes Oak Ridge, Inc., TN (United States). Center for Risk Analysis

    1997-11-01

    Three uranium hexafluoride-(UF{sub 6}-) specific models--HGSYSTEM/UF{sub 6}, Science Application International Corporation, and RTM-96; three dense-gas models--DEGADIS, SLAB, and the Chlorine Institute methodology; and one toxic chemical model--AFTOX--are evaluated on their capabilities to simulate the chemical reactions, thermodynamics, and atmospheric dispersion of UF{sub 6} released from accidents at nuclear fuel-cycle facilities, to support Integrated Safety Analysis, Emergency Response Planning, and Post-Accident Analysis. These models are also evaluated for user-friendliness and for quality assurance and quality control features, to ensure the validity and credibility of the results. Model performance evaluations are conducted for the three UF{sub 6}-specific models, using field data on releases of UF{sub 6} and other heavy gases. Predictions from the HGSYSTEM/UF{sub 6} and SAIC models are within an order of magnitude of the field data, but the SAIC model overpredicts beyond an order of magnitude for a few UF{sub 6}-specific data points. The RTM-96 model provides overpredictions within a factor of 3 for all data points beyond 400 m from the source. For one data set, however, the RTM-96 model severely underpredicts the observations within 200 m of the source. Outputs of the models are most sensitive to the meteorological parameters at large distances from the source and to certain source-specific and meteorological parameters at distances close to the source. Specific recommendations are being made to improve the applicability and usefulness of the three models and to choose a specific model to support the intended analyses. Guidance is also provided on the choice of input parameters for initial dilution, building wake effects, and distance to completion of UF{sub 6} reaction with water.

  13. Fluidized bed calciner apparatus

    DOE Patents [OSTI]

    Owen, Thomas J. (West Richland, WA); Klem, Jr., Michael J. (Richland, WA); Cash, Robert J. (Richland, WA)

    1988-01-01

    An apparatus for remotely calcining a slurry or solution feed stream of toxic or hazardous material, such as ammonium diurante slurry or uranyl nitrate solution, is disclosed. The calcining apparatus includes a vertical substantially cylindrical inner shell disposed in a vertical substantially cylindrical outer shell, in which inner shell is disposed a fluidized bed comprising the feed stream material to be calcined and spherical beads to aid in heat transfer. Extending through the outer and inner shells is a feed nozzle for delivering feed material or a cleaning chemical to the beads. Disposed in and extending across the lower portion of the inner shell and upstream of the fluidized bed is a support member for supporting the fluidized bed, the support member having uniform slots for directing uniform gas flow to the fluidized bed from a fluidizing gas orifice disposed upstream of the support member. Disposed in the lower portion of the inner shell are a plurality of internal electric resistance heaters for heating the fluidized bed. Disposed circumferentially about the outside length of the inner shell are a plurality of external heaters for heating the inner shell thereby heating the fluidized bed. Further, connected to the internal and external heaters is a means for maintaining the fluidized bed temperature to within plus or minus approximately 25.degree. C. of a predetermined bed temperature. Disposed about the external heaters is the outer shell for providing radiative heat reflection back to the inner shell.

  14. Fixed bed hydrocracking process

    SciTech Connect (OSTI)

    MacLean, A.J.; Holloway, R.L.; Lawson, V.A.; Cronen, J.W.

    1990-02-20

    This patent describes a process for converting a gas oil range petroleum feedstock into lighter petroleum products. It comprises: charging the gas oil range petroleum feedstock and hydrogen to a first fixed bed hydrocracking zone containing a hydrocracking catalyst at hydrocracking conditions to produce a first hydrocracking zone product stream; separating the first fixed bed hydrocracking zone product stream in a fractionation zone into a petroleum products stream and a bottoms stream; charging the bottoms stream and hydrogen to a second fixed bed hydrocracking zone containing a hydrocracking catalyst at hydrocracking conditions to produce a second fixed bed hydrocracking zone product stream; cooling the second fixed bed hydrocracking zone product stream to a temperature below about 250{degrees}F; recycling a first portion of the cooled second fixed bed hydrocracking zone product stream to the fractionation zone; removing materials having a boiling range from about 500{degrees} to about 650{degrees}F and a heavy bottoms stream having a boiling point above about 1050{degrees}F from a second portion of the cooled second fixed bed hydrocracking zone product stream to product a treated second portion; and recycling the treated second portion to the first fixed bed hydrocracking zone.

  15. Pulse enhanced fluidized bed combustion

    SciTech Connect (OSTI)

    Mueller, B.

    1996-12-31

    Information is outlined on pulse enhanced fluidized bed combustion. The following topics are discussed: what is pulse enhanced fluidized bed combustion?; pulse combustors; pulsed atmospheric fluidized bed combustor (PAFBC); advantages of PAFBC; performance advantages; PAFBC facts; and PAFBC contact points.

  16. Three-dimensional hydraulic fracture model development for application to and understanding of coal-bed methane-stimulation treatments. Final report, July 1, 1984-December 16, 1988

    SciTech Connect (OSTI)

    Mavko, B.B.; Nielsen, P.E.; Hanson, M.E.

    1989-03-01

    A preliminary three-dimensional numerical model was developed to simulate hydraulically driven fracturing for application to coal seam methane drainage. The initial focus was development of a circular fracture model which served, in part, as a test bed for concepts and formulations applicable to the more general three-dimensional model. Findings from circular model studies were used to design a multiseam fracture treatment. The three-dimensional model involved development of exact influence coefficients for the elastic calculations, inclusion of the aperture time derivative, implementation of an equilibrium tip condition, incorporation of modulus and stress layering, dynamic grid rezoning, incorporation of a two-dimensional fluid flow solution, implementation of the applicable fluid flow boundary conditions, development of a physically realistic fracture front propagation scheme, and proper coupling and control of the various fracture, flow, and calculational model components. Model simulations illustrate important physical effects of fracturing in coal. Preliminary simulations are discussed which show the effects of different viscosity fluids, and effects of stress and modulus variations on vertical fracture containment.

  17. *Supported by the Visiting Scholar Foundation of Shanxi Province P. R. China1 A Fuzzy Neural Network Based on the TS Model with Dynamic Consequent Parameters and its

    E-Print Network [OSTI]

    Lin, Tsau Young

    control system of superheated steam temperature in power plants. The approach is simulated in MATLAB neural-network, TS model, Cascade control, Superheated steam temperature 1. Introduction There are two Network Based on the TS Model with Dynamic Consequent Parameters and its Application to Steam Temperature

  18. An animal model of functional electrical stimulation: evidence that the central nervous system modulates the consequences of training

    E-Print Network [OSTI]

    Grau, James

    system modulates the consequences of training MA Hook*,1 and JW Grau1 1 Department of Psychology, Texas A&M University, College Station, TX, USA Study Design: Review of how spinal neurons can modulate the consequences training 24­48 h after surgery. Experimental manipulations of stimulation parameters, combined

  19. Development of standardized air-blown coal gasifier/gas turbine concepts for future electric power systems. Volume 2, Appendix A: Fixed bed gasifier and sulfur sorbent regeneration subsystem computer model development: Final report

    SciTech Connect (OSTI)

    Blough, E.; Russell, W.; Leach, J.W.

    1990-08-01

    Computer models have been developed for evaluating conceptual designs of integrated coal gasification combined cycle power plants. An overall system model was developed for performing thermodynamic cycle analyses, and detailed models were developed for predicting performance characteristics of fixed bed coal gasifiers and hot gas clean up subsystem components. The overall system model performs mass and energy balances and does chemical equilibrium analyses to determine the effects of changes in operating conditions, or to evaluate proposed design changes. An existing plug flow model for fixed bed gasifiers known as the Wen II model was revised and updated. Also, a spread sheet model of zinc ferrite sulfur sorbent regeneration subsystem was developed. Parametric analyses were performed to determine how performance depends on variables in the system design. The work was done to support CRS Sirrine Incorporated in their study of standardized air blown coal gasifier gas turbine concepts.

  20. Control of bed height in a fluidized bed gasification system

    DOE Patents [OSTI]

    Mehta, Gautam I. (Greensburg, PA); Rogers, Lynn M. (Export, PA)

    1983-12-20

    In a fluidized bed apparatus a method for controlling the height of the fdized bed, taking into account variations in the density of the bed. The method comprises taking simultaneous differential pressure measurements at different vertical elevations within the vessel, averaging the differential pressures, determining an average fluidized bed density, then periodically calculating a weighting factor. The weighting factor is used in the determination of the actual bed height which is used in controlling the fluidizing means.

  1. Hybrid Power Test Bed

    SciTech Connect (OSTI)

    NONE

    1996-06-01

    This document describes efforts by the National Renewable Energy Laboratory to simulate hybrid power systems. Hybrid power systems combine multiple power sources such as wind turbines, photovoltaic (PV) arrays, diesel generators, and battery storage systems. They typically are used in remote areas, away from major electric grids. The Hybrid Power Test Bed is designed to assist the U.S. wind industry in developing and testing hybrid power generation systems. Test bed capabilities, features, and equipment are described.

  2. Sea bed mechanics

    SciTech Connect (OSTI)

    Sleath, J.F.A.

    1984-01-01

    This book provides a discussion on sea bed processes with engineering applications. It brings together the material currently available only in technical reports of research papers. It provides formulae and background references necessary for design calculation of problems such as sea bed or coastal erosion, and sub-marine pipeline stability. It also covers dissipation of wave energy, formation of ripples and dunes, and the transportation of sediments.

  3. IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY, VOL. 8, NO. 2, MARCH 2000 247 A Model of a Bubbling Fluidized Bed Combustor

    E-Print Network [OSTI]

    Campi, Marco

    Prandoni Abstract--Fluidized bed techniques are employed in coal com- bustion power plants, because an appearance in the power plant realm. Compared to a conventional power plant equipped with pollutant abatement, because of the wide contact surface between solid and gas. Known since the 1920's, fluidized bed

  4. Apparatus for controlling fluidized beds

    DOE Patents [OSTI]

    Rehmat, A.G.; Patel, J.G.

    1987-05-12

    An apparatus and process are disclosed for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance. 2 figs.

  5. Apparatus for controlling fluidized beds

    DOE Patents [OSTI]

    Rehmat, Amirali G. (Westmont, IL); Patel, Jitendra G. (Bolingbrook, IL)

    1987-05-12

    An apparatus and process for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance.

  6. Staged fluidized bed

    DOE Patents [OSTI]

    Mallon, R.G.

    1983-05-13

    The invention relates to oil shale retorting and more particularly to staged fluidized bed oil shale retorting. Method and apparatus are disclosed for narrowing the distribution of residence times of any size particle and equalizing the residence times of large and small particles in fluidized beds. Particles are moved up one fluidized column and down a second fluidized column with the relative heights selected to equalize residence times of large and small particles. Additional pairs of columns are staged to narrow the distribution of residence times and provide complete processing of the material.

  7. Transportation Safeguards & Security Test Bed (TSSTB) | ORNL

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Transportation Safeguards and Security Test Bed May 30, 2013 The Transportation Safeguards and Security Test Bed consists of a test-bed vehicle and a monitoringlaboratorytraining...

  8. Stability of Gas-Fluidized Beds

    E-Print Network [OSTI]

    Mandich, Kevin Matthew

    Temperature in a Bubbling Fluidized Bed, To Be Submitted tomechanisms of bubbling in fluidized beds. A simpler analysiswith the nature of bubbling in fluidized beds. When bubbles

  9. A Test Bed for Self-regulating Distribution Systems: Modeling Intergrated Renewable Energy and Demand Response in the GridLAB-D/MATLAB Environment

    SciTech Connect (OSTI)

    Wang, Dan; de Wit, Braydon; Parkinson, Simon; Fuller, Jason C.; Chassin, David P.; Crawford, Curran; Djilali, Ned

    2012-01-16

    This paper discusses the development of a simulation test bed permitting the study of integrated renewable energy generators and controlled distributed heat pumps operating within distribution systems. The test bed is demonstrated in this paper by addressing the important issue of the self-regulating effect of consumer-owned air-source heat pumps on the variability induced by wind power integration, particularly when coupled with increased access to demand response realized through a centralized load control strategy.

  10. Packed Bed Combustion: An Overview

    E-Print Network [OSTI]

    Hallett, William L.H.

    Packed Bed Combustion: An Overview William Hallett Dept. of Mechanical Engineering Université d'Ottawa - University of Ottawa #12;Packed Bed Combustion - University of Ottawa - CICS 2005 Introduction air fuel feedproducts xbed grate Packed Bed Combustion: fairly large particles of solid fuel on a grate, air supplied

  11. Modeling of fluidized-bed combustion of coal: Phase II, final reports. Volume VI. FBC-Data Base-Management-System (FBC-DBMS) development

    SciTech Connect (OSTI)

    Louis, J.F.; Tung, S.E.

    1980-10-01

    The primary goal of the Fluidized Bed Combustor Data Base, (FBCDB), situated in MIT's Energy laboratory, is to establish a data repository for the express use of designers and research personnel involved in FBC development. DBMS is a software that provides an efficient way of storing, retrieving, updating and manipulating data using an English-like query language. It is anticipated that the FBCDB would play an active and a direct role in the development of FBC technology as well as in the FBC commercial application. After some in-house experience and after a careful and extensive review of commercially available database systems, it was determined that the Model 204 DBMS by Computer Corporation of America was the most suitable to our needs. The setup of a prototype in-house database also allowed us to investigate and understand fully the particular problems involved in coordinating FBC development with a DBMS. Various difficult aspects were encountered and solutions had been sought. For instance, we found that it was necessary to rename the variables to avoid repetition as well as to increase usefulness of our database and, hence, we had designed a classification system for which variables were classified under category to achieve standardization of variable names. The primary content of FBCDB is a collection of data points defined by the value of a number of specific FBC variables. A user may interactively access the database from a computer terminal at any location, retrieve, examine, and manipulate the data as well as produce tables or graphs of the results.

  12. Fundamentals of fluidized bed chemical processes

    SciTech Connect (OSTI)

    Yates, J.G.

    1983-01-01

    Chemical processes based on the use of fluidized solids, although widely used on an industrial scale for some four decades, are currently increasing in importance as industry looks for improved methods for handling and reacting solid materials. This book provides background necessary for an understanding of the technique of gas-solid fluidization. Contents: Some Fundamental Aspects of Fluidization-General Features of Gas-Solid Fluidization; Minimum Fluidization Velocity; Inter-particle forces; Liquid-Solid Fluidization; Bubbles; Slugging; Entrainment and Elutriation; Particle Movement; Bed Viscosity; Fluidization Under Pressure. Fluidized-Bed Reactor Models-ome Individual Models; Model Comparisons; Multiple Region Models. Catalytic Cracking-Process Developments Riser Cracking; Catalysis; Process Chemistry; Kinetics; Process Models. Combustion and Gasification-Plant Developments; Oil and Gas Combustion; Desulphurization; No/sub x/ Emissions; Coal Gassification. Miscellaneous Processes-Phthalic Anhydride (1,3-isobezofurandione); Acrylonitrile (prop-3-enenitrile); Vinyl Chloride (chloroethene); Titanium Dioxide; Uranium Processing; Sulphide Roasting; Indexes.

  13. Wavy Instability in Liquid-Fluidized Beds Maxime Nicolas, John Hinch, and E lisabeth Guazzelli*,

    E-Print Network [OSTI]

    Hinch, John

    . Gas-fluidized beds are very unstable and rapidly attain a bubbling regime. In this regime, bubblesWavy Instability in Liquid-Fluidized Beds Maxime Nicolas, John Hinch, and EÄ lisabeth Guazzelli. The validity of the two-phase Newtonian model is then questioned. 1. Introduction To fluidize a bed

  14. Effect of air distribution on solid fuel bed combustion

    SciTech Connect (OSTI)

    Kuo, J.T.; Hsu, W.S.; Yo, T.C.

    1996-09-01

    One important aspect of refuse mass-burn combination control is the manipulation of combustion air. Proper air manipulation is key to the achievement of good combustion efficiency and reduction of pollutant emissions. Experiments, using a small fix-grate laboratory furnace with cylindrical combustion chamber, were performed to investigate the influence of undergrate/sidewall air distribution on the combustion of beds of wood cubes. Wood cubes were used as a convenient laboratory surrogate of solid refuse. Specifically, for different bed configurations (e.g. bed height, bed voidage and bed fuel size, etc.), burning rates and combustion temperatures at different bed locations were measured under various air supply and distribution conditions. One of the significant results of the experimental investigation is that combustion, with air injected from side walls and no undergrate air, provide the most efficient combustion. On the other hand, combustion with undergrate air achieves higher combustion rates but with higher CO emissions. A simple one-dimensional model was constructed to derive correlations of combustion rate as functions of flue gas temperature and oxygen concentration. Despite the fact that the model is one dimensional and many detailed chemical and physical processes of combustion are not considered, comparisons of the model predictions and the experimental results indicate that the model is appropriate for quantitative evaluation of bed burning rates.

  15. Coal Bed Methane Primer

    SciTech Connect (OSTI)

    Dan Arthur; Bruce Langhus; Jon Seekins

    2005-05-25

    During the second half of the 1990's Coal Bed Methane (CBM) production increased dramatically nationwide to represent a significant new source of income and natural gas for many independent and established producers. Matching these soaring production rates during this period was a heightened public awareness of environmental concerns. These concerns left unexplained and under-addressed have created a significant growth in public involvement generating literally thousands of unfocused project comments for various regional NEPA efforts resulting in the delayed development of public and fee lands. The accelerating interest in CBM development coupled to the growth in public involvement has prompted the conceptualization of this project for the development of a CBM Primer. The Primer is designed to serve as a summary document, which introduces and encapsulates information pertinent to the development of Coal Bed Methane (CBM), including focused discussions of coal deposits, methane as a natural formed gas, split mineral estates, development techniques, operational issues, producing methods, applicable regulatory frameworks, land and resource management, mitigation measures, preparation of project plans, data availability, Indian Trust issues and relevant environmental technologies. An important aspect of gaining access to federal, state, tribal, or fee lands involves education of a broad array of stakeholders, including land and mineral owners, regulators, conservationists, tribal governments, special interest groups, and numerous others that could be impacted by the development of coal bed methane. Perhaps the most crucial aspect of successfully developing CBM resources is stakeholder education. Currently, an inconsistent picture of CBM exists. There is a significant lack of understanding on the parts of nearly all stakeholders, including industry, government, special interest groups, and land owners. It is envisioned the Primer would being used by a variety of stakeholders to present a consistent and complete synopsis of the key issues involved with CBM. In light of the numerous CBM NEPA documents under development this Primer could be used to support various public scoping meetings and required public hearings throughout the Western States in the coming years.

  16. Biparticle fluidized bed reactor

    DOE Patents [OSTI]

    Scott, Charles D. (Oak Ridge, TN); Marasco, Joseph A. (Kingston, TN)

    1995-01-01

    A fluidized bed reactor system utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves.

  17. Biparticle fluidized bed reactor

    DOE Patents [OSTI]

    Scott, Charles D. (Oak Ridge, TN)

    1993-01-01

    A fluidized bed reactor system which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves.

  18. Biparticle fluidized bed reactor

    DOE Patents [OSTI]

    Scott, Charles D. (Oak Ridge, TN); Marasco, Joseph A. (Kingston, TN)

    1996-01-01

    A fluidized bed reactor system which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary and tertiary particulate phases, continuously introduced and removed simultaneously in the cocurrent and countercurrent mode, act in a role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Means for introducing and removing the sorbent phases include feed screw mechanisms and multivane slurry valves.

  19. Biparticle fluidized bed reactor

    DOE Patents [OSTI]

    Scott, C.D.; Marasco, J.A.

    1995-04-25

    A fluidized bed reactor system utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves. 3 figs.

  20. Biparticle fluidized bed reactor

    DOE Patents [OSTI]

    Scott, C.D.

    1993-12-14

    A fluidized bed reactor system which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase is described. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary particulate phase, continuously introduced and removed in either cocurrent or countercurrent mode, acts in a secondary role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Introduction and removal of the sorbent phase is accomplished through the use of feed screw mechanisms and multivane slurry valves. 3 figures.

  1. Biparticle fluidized bed reactor

    DOE Patents [OSTI]

    Scott, C.D.; Marasco, J.A.

    1996-02-27

    A fluidized bed reactor system is described which utilizes a fluid phase, a retained fluidized primary particulate phase, and a migratory second particulate phase. The primary particulate phase is a particle such as a gel bead containing an immobilized biocatalyst. The secondary and tertiary particulate phases, continuously introduced and removed simultaneously in the cocurrent and countercurrent mode, act in a role such as a sorbent to continuously remove a product or by-product constituent from the fluid phase. Means for introducing and removing the sorbent phases include feed screw mechanisms and multivane slurry valves. 3 figs.

  2. Fluidized bed boiler feed system

    DOE Patents [OSTI]

    Jones, Brian C. (Windsor, CT)

    1981-01-01

    A fluidized bed boiler feed system for the combustion of pulverized coal. Coal is first screened to separate large from small particles. Large particles of coal are fed directly to the top of the fluidized bed while fine particles are first mixed with recycled char, preheated, and then fed into the interior of the fluidized bed to promote char burnout and to avoid elutriation and carryover.

  3. Method for packing chromatographic beds

    DOE Patents [OSTI]

    Freeman, David H. (Potomac, MD); Angeles, Rosalie M. (Germantown, MD); Keller, Suzanne (Rockville, MD)

    1991-01-01

    Column chromatography beds are packed through the application of static force. A slurry of the chromatography bed material and a non-viscous liquid is filled into the column plugged at one end, and allowed to settle. The column is transferred to a centrifuge, and centrifuged for a brief period of time to achieve a predetermined packing level, at a range generally of 100-5,000 gravities. Thereafter, the plug is removed, other fixtures may be secured, and the liquid is allowed to flow out through the bed. This results in an evenly packed bed, with no channeling or preferential flow characteristics.

  4. Pressurized fluidized bed reactor

    DOE Patents [OSTI]

    Isaksson, J.

    1996-03-19

    A pressurized fluid bed reactor power plant includes a fluidized bed reactor contained within a pressure vessel with a pressurized gas volume between the reactor and the vessel. A first conduit supplies primary gas from the gas volume to the reactor, passing outside the pressure vessel and then returning through the pressure vessel to the reactor, and pressurized gas is supplied from a compressor through a second conduit to the gas volume. A third conduit, comprising a hot gas discharge, carries gases from the reactor, through a filter, and ultimately to a turbine. During normal operation of the plant, pressurized gas is withdrawn from the gas volume through the first conduit and introduced into the reactor at a substantially continuously controlled rate as the primary gas to the reactor. In response to an operational disturbance of the plant, the flow of gas in the first, second, and third conduits is terminated, and thereafter the pressure in the gas volume and in the reactor is substantially simultaneously reduced by opening pressure relief valves in the first and third conduits, and optionally by passing air directly from the second conduit to the turbine. 1 fig.

  5. Pressurized fluidized bed reactor

    DOE Patents [OSTI]

    Isaksson, Juhani (Karhula, FI)

    1996-01-01

    A pressurized fluid bed reactor power plant includes a fluidized bed reactor contained within a pressure vessel with a pressurized gas volume between the reactor and the vessel. A first conduit supplies primary gas from the gas volume to the reactor, passing outside the pressure vessel and then returning through the pressure vessel to the reactor, and pressurized gas is supplied from a compressor through a second conduit to the gas volume. A third conduit, comprising a hot gas discharge, carries gases from the reactor, through a filter, and ultimately to a turbine. During normal operation of the plant, pressurized gas is withdrawn from the gas volume through the first conduit and introduced into the reactor at a substantially continuously controlled rate as the primary gas to the reactor. In response to an operational disturbance of the plant, the flow of gas in the first, second, and third conduits is terminated, and thereafter the pressure in the gas volume and in the reactor is substantially simultaneously reduced by opening pressure relief valves in the first and third conduits, and optionally by passing air directly from the second conduit to the turbine.

  6. Flow in internet shopping: a validity study and an examination of a model specifying antecedents and consequences of flow 

    E-Print Network [OSTI]

    Guo, Yi

    2005-02-17

    fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY December 2004 Major Subject: Information and Operations Management FLOW IN INTERNET SHOPPING: A VALIDITY STUDY AND AN EXAMINATION OF A MODEL SPECIFYING...) ____________________________ ____________________________ Manjit Yadav Dean Wichern (Member) (Head of Department) December 2004 Major Subject: Information and Operations Management iii ABSTRACT Flow in Internet Shopping: A Validity Study and an Examination of a...

  7. Stochastic modeling of the variation of velocity and permeability as a function of effective pressure using the Bed-of-Nails asperity-deformation model 

    E-Print Network [OSTI]

    Genova Barazarte, Ezequiel

    2009-05-15

    of confining and pore-fluid pressures in a deep-sea chalk showed that the best-fitting asperity-deformation model is sensitive to the effective-pressure model. Measurements of permeability in a Navajo-sandstone specimen as a function of confining pressure were...

  8. Pulsed atmospheric fluidized bed combustion

    SciTech Connect (OSTI)

    Not Available

    1992-08-01

    The general specifications for a Pulsed Atmospheric Fluidized Bed Combustor Design Report (PAFBC) plant are presented. The design tasks for the PAFBC are described in the following areas: Coal/Limestone preparation and feed system; pulse combustor; fluidized bed; boiler parts; and ash handling system.

  9. Dynamic bed reactor

    DOE Patents [OSTI]

    Stormo, Keith E. (Moscow, ID)

    1996-07-02

    A dynamic bed reactor is disclosed in which a compressible open cell foam matrix is periodically compressed and expanded to move a liquid or fluid through the matrix. In preferred embodiments, the matrix contains an active material such as an enzyme, biological cell, chelating agent, oligonucleotide, adsorbent or other material that acts upon the liquid or fluid passing through the matrix. The active material may be physically immobilized in the matrix, or attached by covalent or ionic bonds. Microbeads, substantially all of which have diameters less than 50 microns, can be used to immobilize the active material in the matrix and further improve reactor efficiency. A particularly preferred matrix is made of open cell polyurethane foam, which adsorbs pollutants such as polychlorophenol or o-nitrophenol. The reactors of the present invention allow unidirectional non-laminar flow through the matrix, and promote intimate exposure of liquid reactants to active agents such as microorganisms immobilized in the matrix.

  10. National SCADA Test Bed | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Cybersecurity Energy Delivery Systems Cybersecurity National SCADA Test Bed National SCADA Test Bed Created in 2003, the National SCADA Test Bed (NSTB) is a one-of-a-kind...

  11. Our Sun. IV. The Standard Model and Helioseismology: Consequences of Uncertainties in Input Physics and in Observed Solar Parameters

    E-Print Network [OSTI]

    Arnold I. Boothroyd; I. -Juliana Sackmann

    2002-10-04

    Helioseismology provides a powerful tool to explore the deep interior of the Sun: for example, the adiabatic sound speed can be inferred with an accuracy of a few parts in 10,000. This has become a serious challenge to theoretical models of the Sun. Therefore, we have undertaken a self-consistent, systematic study of sources of uncertainties in the standard solar model, which must be understood before the helioseismic observations can be used as constraints on theory. We find that the largest uncertainty in the sound speed in the solar interior, namely, 3 parts in 1000, arises from uncertainties in the observed photospheric abundances of the elements; uncertainties of 1 part in 1000 arise from (1) the 4% uncertainty in the OPAL opacities, (2) the 5% uncertainty in the basic pp nuclear reaction rate, (3) the 15% uncertainty in the diffusion constants for the gravitational settling of helium, and (4) the 50% uncertainties in diffusion constants for the heavier elements. (Other investigators have shown that similar uncertainties arise from uncertainties in the interior equation of state and in rotation-induced turbulent mixing.) The predicted pre-main-sequence solar lithium depletion is a factor of order 20 (an order of magnitude larger than that predicted by earlier models that neglected gravitational settling and used older opacities), and is uncertain by a factor of 2. The predicted neutrino capture rate is uncertain by 30% for the Cl-37 experiment and by 3% for the Ga-71 experiments (not including uncertainties in the capture cross sections), while the B-8 neutrino flux is uncertain by 30%.

  12. Behavior of fluidized beds similar to equilibrium states

    E-Print Network [OSTI]

    Kengo Ichiki; Hisao Hayakawa

    1997-04-25

    Systematic simulations are carried out based on the model of fluidized beds proposed by the present authors [K.Ichiki and H.Hayakawa, Phys. Rev. E vol.52, 658 (1995)]. From our simulation, we confirm that fluidization is a continuous transition. We also confirm the existence of two types of fluidized phases, the channeling phase and the bubbling phase. We find the close relations between the averaged behaviors in fluidized beds and quasi equilibrium states in dense liquids. In fluidized beds, (i) the flow rate plays the role of the effective temperature, and (ii) the existence of a kind of the fluctuation-dissipation relation is suggested.

  13. Fluidized bed gasification of agricultural residue 

    E-Print Network [OSTI]

    Groves, John David

    1979-01-01

    at the operat- ing conditions used. The experimental data were also used to develop an empirical model based on temperature, fuel to air ratio, and their interactions. Cotton gin wastes were gasified with air to provide a fuel gas suitable for use... system include material balances for each of the components, process operating conditions, and applicable equilibrium relationships. Gumz (1950) applied these meth- ods to estimate the equilibrium gas composition from a fixed bed coal gasifier...

  14. Pulse enhanced fluidized bed combustion

    SciTech Connect (OSTI)

    Mueller, B.; Golan, L. [South Carolina Energy Research and Development Center, Clemson, SC (United States); Toma, M.; Mansour, M. [Manufacturing and Technology Conversion International, Inc., Columbia, MD (United States)

    1996-12-31

    Various technologies are available for the combustion of high-sulfur, high-ash fuels, particularly coal. From performance, economic and environmental standpoints, fluidized bed combustion (FBC) is the leading candidate for utilization of high sulfur coals. ThermoChem, Inc., and the South Carolina Energy Research and Development Center (SCERDC) are installing a hybrid fluidized bed combustion system at Clemson University. This hybrid system, known as the Pulsed Atmospheric Fluidized Bed Combustor (PAFBC), will augment the University`s steam system by providing 50--60,000 lbs/hr of saturated process steam. The PAFBC, developed by Manufacturing and Technology Conversion International, Inc., (MTCI), integrates a pulse combustor with a bubbling-bed-type atmospheric fluidized bed coal combustor. The pulse combustion system imparts an acoustic effect that enhances combustion efficiency, SO{sub 2} capture, low NO{sub x} emissions, and heat transfer efficiency in the fluidized bed. These benefits of pulse combustion result in modestly sized PAFBC units with high throughput rates and lower costs when compared to conventional fluidized bed units.

  15. Moving granular-bed filter development program. Topical report

    SciTech Connect (OSTI)

    Newby, R.A.; Yang, W.C.; Smeltzer, E.E.; Lippert, T.E.

    1994-04-01

    Advanced, coal-based, power plants, such as IGCC and Advanced-PFBC, are currently nearing commercial demonstration. These power plant technologies require hot gas filtration as part of their gas cleaning trains. Ceramic barrier filters are the major filter candidates being developed for these hot gas cleaning applications. While ceramic barrier filters achieve high levels of particle removal, concerns exist for their reliability and operability in these applications. An alternative hot gas filtration technology is the moving granular bed filter. An advanced, moving granular bed filter has been conceived, and early development activities performed by the Westinghouse Electric Corporation, Science and Technology Center. This document reports on the Base Contract tasks performed to resolve the barrier technical issues for this technology. The concept, the Standleg Moving Granular Bed Filter (SMGBF) has a concurrent downward, gas and bed media flow configuration that results in simplified features and improved scaleup feasibility compared to alternative designs. Two modes of bed media operation were assessed in the program: once-through using pelletized power plant waste as bed media, and recycle of bed media via standleg and pneumatic transport techniques. Cold Model testing; high-temperature, high-pressure testing; and pelletization testing using advanced power plant wastes, have been conducted in the program. A commercial, economic assessment of the SMGBF technology was performed for IGCC and Advanced-PFBC applications. The evaluation shows that the barrier technical issues can be resolved, and that the technology is potentially competitive with ceramic barrier filters.

  16. Gas Bubbles Emerging from a Submerged Granular Bed

    E-Print Network [OSTI]

    Meier, John A; Brennen, Christopher E

    2009-01-01

    This fluid dynamics video was submitted to the Gallery of Fluid Motion for the 2009 APS Division of Fluid Dynamics Meeting in Minneapolis, Minnesota. In this video we show some results from a simple experiment where air was injected by a single nozzle at known constant flow rates in the bottom of a granular bed submerged in water. The injected air propagates through the granular bed in one of two modes. Mode 1 emergence involves small discrete bubbles taking tortuous paths through the interstitial space of the bed. Multiple small bubbles can be emitted from the bed in an array of locations at the same time during Mode 1 emergence. Mode 2 emergence involves large discrete bubbles locally fluidizing the granular bed and exiting the bed approximately above the injection site. Bead diameter, bead density, and air flow rate were varied to investigate the change in bubble release behavior at the top of the granular bed. This system is a useful model for methane seeps in lakes. Methane bubbles are released from the ...

  17. Simulation of a High Efficiency Multi-bed Adsorption Heat Pump

    SciTech Connect (OSTI)

    TeGrotenhuis, Ward E.; Humble, Paul H.; Sweeney, J. B.

    2012-05-01

    Attaining high energy efficiency with adsorption heat pumps is challenging due to thermodynamic losses that occur when the sorbent beds are thermally cycled without effective heat recuperation. The multi-bed concept described here effectively transfers heat from beds being cooled to beds being heated, which enables high efficiency in thermally driven heat pumps. A simplified lumped-parameter model and detailed finite element analysis are used to simulate the performance of an ammonia-carbon sorption compressor, which is used to project the overall heat pump coefficient of performance. The effects of bed geometry and number of beds on system performance are explored, and the majority of the performance benefit is obtained with four beds. Results indicate that a COP of 1.24 based on heat input is feasible at AHRI standard test conditions for residential HVAC equipment. When compared on a basis of primary energy input, performance equivalent to SEER 13 or 14 are theoretically attainable with this system.

  18. Pulsed atmospheric fluidized bed combustion

    SciTech Connect (OSTI)

    Not Available

    1992-10-01

    The design of the Pulsed Atmospheric Fluidized Bed Combustor (PAFBC) as described in the Quarterly Report for the period April--June, 1992 was reviewed and minor modifications were included. The most important change made was in the coal/limestone preparation and feed system. Instead of procuring pre-sized coal for testing of the PAFBC, it was decided that the installation of a milling system would permit greater flexibility in the testing with respect to size distributions and combustion characteristics in the pulse combustor and the fluid bed. Particle size separation for pulse combustor and fluid bed will be performed by an air classifier. The modified process flow diagram for the coal/limestone handling system is presented in Figure 1. The modified process flow diagrams of the fluidized bed/steam cycle and ash handling systems are presented in Figures 2 and 3, respectively.

  19. Continuous Bed Ion Exchange Column

    E-Print Network [OSTI]

    Lebendiker, Mario

    UNOTM Q&S Continuous Bed Ion Exchange Column Instruction Manual Catalog Numbers 720-0001, 720 with 5 column volumes of water. Elevated backpressures may occur when wash- ing with deionized water. Do

  20. Effect of bed pressure drop on performance of a CFB boiler

    SciTech Connect (OSTI)

    Hairui Yang; Hai Zhang; Shi Yang; Guangxi Yue; Jun Su; Zhiping Fu

    2009-05-15

    The effect of bed pressure drop and bed inventory on the performances of a circulating fluidized bed (CFB) boiler was studied. By using the state specification design theory, the fluidization state of the gas-solids flow in the furnace of conventional CFB boilers was reconstructed to operate at a much lower bed pressure drop by reducing bed inventory and control bed quality. Through theoretical analysis, it was suggested that there would exist a theoretical optimal value of bed pressure drop, around which the boiler operation can achieve the maximal combustion efficiency and with significant reduction of the wear of the heating surface and fan energy consumption. The analysis was validated by field tests carried out in a 75 t/h CFB boiler. At full boiler load, when bed pressure drop was reduced from 7.3 to 3.2 kPa, the height of the dense zone in the lower furnace decreased, but the solid suspension density profile in the upper furnace and solid flow rate were barely influenced. Consequently, the average heat transfer coefficient in the furnace was kept nearly the same and the furnace temperature increment was less than 17{sup o}C. It was also found that the carbon content in the fly ash decreased first with decreasing bed pressure drop and then increased with further increasing bed pressure drop. The turning point with minimal carbon content was referred to as the point with optimal bed pressure drop. For this boiler, at the optimum point the bed pressure was around 5.7 kPa with the overall excess air ratio of 1.06. When the boiler was operated around this optimal point, not only the combustion efficiency was improved, but also fan energy consumption and wear of heating surface were reduced. 23 refs., 6 figs., 4 tabs.

  1. Numerical Analysis of using a Fluidized Bed as a Prototypic Mass Production Device for IFE Target Layering

    E-Print Network [OSTI]

    Raffray, A. René

    of the target to reduce the heat transfer onto the target during injection into the reactor chamber1 . After several topics, including the effect of unbalanced spheres on the bed behavior and ultimately for the fluidized bed model, as it affects the unbalance of the individual spheres. Keywords- Fluidized bed, IFE

  2. Bed-inventory Overturn Mechanism for Pant-leg Circulating Fluidized Bed Boilers

    E-Print Network [OSTI]

    Wang, Zhe; Yang, Zhiwei; West, Logan; Li, Zheng

    2011-01-01

    A numerical model was established to investigate the lateral mass transfer as well as the mechanism of bed-inventory overturn inside a pant-leg circulating fluidized bed (CFB), which are of great importance to maintain safe and efficient operation of the CFB. Results show that the special flow structure in which the solid particle volume fraction along the central line of the pant-leg CFB is relative high enlarges the lateral mass transfer rate and make it more possible for bed inventory overturn. Although the lateral pressure difference generated from lateral mass transfer inhibits continuing lateral mass transfer, providing the pant-leg CFB with self-balancing ability to some extent, the primary flow rate change due to the outlet pressure change often disable the self-balancing ability by continually enhancing the flow rate difference. As the flow rate of the primary air fan is more sensitive to its outlet pressure, it is easier to lead to bed inventory overturn. While when the solid particle is easier to c...

  3. Onset and cessation of motion in hydrodynamically sheared granular beds

    E-Print Network [OSTI]

    Abram H. Clark; Mark D. Shattuck; Nicholas T. Ouellette; Corey S. O'Hern

    2015-10-06

    We performed molecular dynamics simulations of granular beds driven by a model hydrodynamic shear flow to elucidate general grain-scale mechanisms that determine the onset and cessation of sediment transport. By varying the Shields number (the nondimensional shear stress at the top of the bed) and particle Reynolds number (the ratio of particle inertia to viscous damping), we explore how variations of the fluid flow rate, particle inertia, and fluid viscosity affect the onset and cessation of bed motion. For low to moderate particle Reynolds numbers, a critical boundary separates mobile and static states. Transition times between these states diverge as this boundary is approached both from above and below. At high particle Reynolds number, inertial effects become dominant, and particle motion can be sustained well below flow rates at which mobilization of a static bed occurs. We also find that the onset of bed motion (for both low and high particle Reynolds numbers) is described by Weibullian weakest-link statistics, and thus is crucially dependent on the packing structure of the granular bed, even deep beneath the surface.

  4. Health effects models for nuclear power plant accident consequence analysis: Low LET radiation: Part 2, Scientific bases for health effects models

    SciTech Connect (OSTI)

    Abrahamson, S.; Bender, M.; Book, S.; Buncher, C.; Denniston, C.; Gilbert, E.; Hahn, F.; Hertzberg, V.; Maxon, H.; Scott, B.

    1989-05-01

    This report provides dose-response models intended to be used in estimating the radiological health effects of nuclear power plant accidents. Models of early and continuing effects, cancers and thyroid nodules, and genetic effects are provided. Two-parameter Weibull hazard functions are recommended for estimating the risks of early and continuing health effects. Three potentially lethal early effects -- the hematopoietic, pulmonary and gastrointestinal syndromes -- are considered. Linear and linear-quadratic models are recommended for estimating cancer risks. Parameters are given for analyzing the risks of seven types of cancer in adults -- leukemia, bone, lung, breast, gastrointestinal, thyroid and ''other''. The category, ''other'' cancers, is intended to reflect the combined risks of multiple myeloma, lymphoma, and cancers of the bladder, kidney, brain, ovary, uterus and cervix. Models of childhood cancers due to in utero exposure are also provided. For most cancers, both incidence and mortality are addressed. Linear and linear-quadratic models are also recommended for assessing genetic risks. Five classes of genetic disease -- dominant, x-linked, aneuploidy, unbalanced translocation and multifactorial diseases --are considered. In addition, the impact of radiation-induced genetic damage on the incidence of peri-implantation embryo losses is discussed. The uncertainty in modeling radiological health risks is addressed by providing central, upper, and lower estimates of all model parameters. Data are provided which should enable analysts to consider the timing and severity of each type of health risk. 22 refs., 14 figs., 51 tabs.

  5. COMPARING SIMULATION METHODS FOR FIRE SPREADING ACROSS A FUEL BED

    E-Print Network [OSTI]

    Wainer, Gabriel

    choice to solve the problem. Diffusion processes (oil spills, fire spread, insect infestation, etcCOMPARING SIMULATION METHODS FOR FIRE SPREADING ACROSS A FUEL BED Alexandre Muzy Computer Modeling computer simulation of a semi-physical fire spread model. Forest fire is a com- plex phenomenon, which

  6. Apparatus and process for controlling fluidized beds

    DOE Patents [OSTI]

    Rehmat, Amirali G. (Westmont, IL); Patel, Jitendra G. (Bolingbrook, IL)

    1985-10-01

    An apparatus and process for control and maintenance of fluidized beds under non-steady state conditions. An ash removal conduit is provided for removing solid particulates from a fluidized bed separate from an ash discharge conduit in the lower portion of the grate supporting such a bed. The apparatus and process of this invention is particularly suitable for use in ash agglomerating fluidized beds and provides control of the fluidized bed before ash agglomeration is initiated and during upset conditions resulting in stable, sinter-free fluidized bed maintenance.

  7. CIRCULATING MOVING BED COMBUSTION PROOF OF CONCEPT

    SciTech Connect (OSTI)

    Jukkola, Glen

    2010-06-30

    Circulating Moving Bed (CMB) combustion technology has its roots in traditional circulating fluidized bed technology and involves a novel method of solid fuel combustion and heat transfer. CMB technology represents a step change in improved performance and cost relative to conventional PC and FBC boilers. The CMB heat exchanger preheats the energy cycle working fluid, steam or air, to the high temperature levels required in systems for advanced power generation. Unique features of the CMB are the reduction of the heat transfer surfaces by about 60% as a result of the enhanced heat transfer rates, flexibility of operation, and about 30% lower cost over existing technology. The CMB Phase I project ran from July 2001 through March 2003. Its objective was to continue development of the CMB technology with a series of proof of concept tests. The tests were conducted at a scale that provided design data for scale up to a demonstration plant. These objectives were met by conducting a series of experiments in ALSTOM Power’s Multi-use Test Facility (MTF). The MTF was modified to operate under CMB conditions of commercial interest. The objective of the tests were to evaluate gas-to-solids heat transfer in the upper furnace, assess agglomeration in the high temperature CMB bubbling bed, and evaluate solids-to-tube heat transfer in the moving bed heat exchanger. The Phase I program results showed that there are still some significant technical uncertainties that needed to be resolved before the technology can be confidently scaled up for a successful demonstration plant design. Work remained in three primary areas: • scale up of gas to solid heat transfer • high temperature finned surface design • the overall requirements of mechanical and process design. The CMB Phase II workscope built upon the results of Phase I and specifically addressed the remaining technical uncertainties. It included a scaled MTF heat transfer test to provide the necessary data to scale up gas-to-solids heat transfer. A stress test rig was built and tested to provide validation data for a stress model needed to support high temperature finned surface design. Additional cold flow model tests and MTF tests were conducted to address mechanical and process design issues. This information was then used to design and cost a commercial CMB design concept. Finally, the MBHE was reconfigured into a slice arrangement and tested for an extended duration at a commercial CFB plant.

  8. Fluidization quality analyzer for fluidized beds

    DOE Patents [OSTI]

    Daw, C. Stuart (Knoxville, TN); Hawk, James A. (Oak Ridge, TN)

    1995-01-01

    A control loop and fluidization quality analyzer for a fluidized bed utilizes time varying pressure drop measurements. A fast-response pressure transducer measures the overall bed pressure drop, or over some segment of the bed, and the pressure drop signal is processed to produce an output voltage which changes with the degree of fluidization turbulence.

  9. Fluidization quality analyzer for fluidized beds

    DOE Patents [OSTI]

    Daw, C.S.; Hawk, J.A.

    1995-07-25

    A control loop and fluidization quality analyzer for a fluidized bed utilizes time varying pressure drop measurements. A fast-response pressure transducer measures the overall bed pressure drop, or over some segment of the bed, and the pressure drop signal is processed to produce an output voltage which changes with the degree of fluidization turbulence. 9 figs.

  10. Initial Design of a Dual Fluidized Bed Reactor

    E-Print Network [OSTI]

    Yun, Minyoung

    2014-01-01

    fast bed and (b) the bubbling fluidized bed on gas mixingflow regimes. (A) A bubbling fluidized bed, (B) turbulent1.5, 1.6. 1. Bubbling fluidized bed gasifiers (BFB) (Figure

  11. Non-convex flux functions and compound shock waves in sediment beds

    E-Print Network [OSTI]

    De Sterck, Hans

    Non-convex flux functions and compound shock waves in sediment beds Gert Bartholomeeusen1 , Hans De of Engineering Science, Parks Road, Oxford OX1 3PJ, UK gilliane.sills@eng.ox.ac.uk Summary. Sediment layers in sediment beds and the numerical modelling of the sedimentation process using an experimentally obtained

  12. Agent-Based Test Beds for the Integrated Study of Transmission-Distribution Operations

    E-Print Network [OSTI]

    LAB-D to realistically model the distribution system 2 #12;Integrated Retail and Wholesale (IRW) Power System Test Bed Xx xx 3 #12;AMES Wholesale Power Market Test Bed 4 AMES Homepage: http://www2.econ Workshop, March 24-25, 2015 NIST, Gaithersburg, Maryland 1 #12;Presentation Outline Integrated Retail

  13. Bed BugsBed Bugs Bed bugs are small, wingless insects that

    E-Print Network [OSTI]

    Ishida, Yuko

    insecticide treatments. If you are a renter, contact your landlord or property owner to help manage't control bed bugs. Remove or heat-treat infested materials, and seal hiding spots to prevent future infestations. Inspect after treatments to be sure bugs are gone. May 2015 Minimize the use of pesticides

  14. Method and apparatus for a combination moving bed thermal treatment reactor and moving bed filter

    DOE Patents [OSTI]

    Badger, Phillip C.; Dunn, Jr., Kenneth J.

    2015-09-01

    A moving bed gasification/thermal treatment reactor includes a geometry in which moving bed reactor particles serve as both a moving bed filter and a heat carrier to provide thermal energy for thermal treatment reactions, such that the moving bed filter and the heat carrier are one and the same to remove solid particulates or droplets generated by thermal treatment processes or injected into the moving bed filter from other sources.

  15. MODULAR PEBBLE BED REACTOR PROJECT UNIVERSITY RESEARCH CONSORTIUM

    E-Print Network [OSTI]

    includes the development of a fission gas release model, particle temperature distributions, internal conceptual design for a gas-cooled, modular, pebble bed reactor. Key technology areas associated particle pressure, migration of fission products, and chemical attack of fuel particle layers. · A balance

  16. Pulsed atmospheric fluidized bed combustion

    SciTech Connect (OSTI)

    Not Available

    1992-05-01

    During this first quarter, a lab-scale water-cooled pulse combustor was designed, fabricated, and integrated with old pilot-scale PAFBC test systems. Characterization tests on this pulse combustor firing different kinds of fuel -- natural gas, pulverized coal and fine coal -- were conducted (without fluidized bed operation) for the purpose of finalizing PAFBC full-scale design. Steady-state tests were performed. Heat transfer performance and combustion efficiency of a coal-fired pulse combustor were evaluated.

  17. Rivesville multicell fluidized bed boiler

    SciTech Connect (OSTI)

    Not Available

    1981-03-01

    One objective of the experimental MFB at Rivesville, WV, was the evaluation of alternate feed systems for injecting coal and limestone into a fluidized bed. A continuous, uniform feed flow to the fluid bed is essential in order to maintain stable operations. The feed system originally installed on the MFB was a gravity feed system with an air assist to help overcome the back pressure created by the fluid bed. The system contained belt, vibrating, and rotary feeders which have been proven adequate in other material handling applications. This system, while usable, had several operational and feeding problems during the MFB testing. A major portion of these problems occurred because the coal and limestone feed control points - a belt feeder and rotary feeder, respectively - were pressurized in the air assist system. These control points were not designed for pressurized service. An alternate feed system which could accept feed from the two control points, split the feed into six equal parts and eliminate the problems of the pressurized system was sought. An alternate feed system designed and built by the Fuller Company was installed and tested at the Rivesville facility. Fuller feed systems were installed on the north and south side of C cell at the Rivesville facility. The systems were designed to handle 10,000 lb/hr of coal and limestone apiece. The systems were installed in late 1979 and evaluated from December 1979 to December 1980. During this time period, nearly 1000 h of operating time was accumulated on each system.

  18. Overall and average local heat transfer from a horizontal cylinder in a gas-fluidized bed with an opposing oscillatory flow

    SciTech Connect (OSTI)

    Pence, D.V. [Univ. of Rhode Island, Kingston, RI (United States). Dept. of Mechanical Engineering and Applied Mechanics; Beasley, D.E. [Clemson Univ., SC (United States). Dept. of Mechanical Engineering

    1996-12-31

    The Pulsed Atmospheric Fluidized Bed Combustor (PAFBC), a hybrid combustor concept that couples a pulsed combustor with an atmospheric bubbling fluidized bed, has technical advantages in energy efficiency and emissions. The present study examines fundamental aspects of heat transfer in this hybrid combustor by measuring the effect of an opposing oscillatory flow on the overall and time-averaged local heat transfer in a laboratory scale bubbling gas-fluidized bed. This opposing secondary flow consisted of a steady mean component and an oscillating component thereby modeling the flow in the tailpipe of a pulsed combustor. Data were acquired for a monodisperse distribution of particles with a mean diameter of 345 {micro}m and total fluidization ratios ranging from 1.1 through 2.7. Overall and time-averaged local heat flux measurements from the surface of a submerged horizontal cylinder show that heat transfer characteristics are significantly altered by an opposing oscillatory flow. Increases in overall heat transfer on the order of 12% were identified for operating conditions with low primary and secondary flow rates and low pulse frequencies. These enhancements were identified to be a consequence of significant localized enhancements. The fundamental trends and magnitude of the particle Nusselt number are effectively characterized by a modified form of the Strouhal number.

  19. Pulsed atmospheric fluidized bed combustion

    SciTech Connect (OSTI)

    Not Available

    1993-01-01

    The Design and Engineering of most components in the Pulsed Atmospheric Fluidized Bed System was completed prior to September 1992. The components remaining to be designed at that time were: Aerovalves for the Pulse Combustor; Gas and coal injectors for the Pulse Combustor; Lines for PC tailpipes; Air plenum and inlet silencer; Refractory lined hot gas duct connecting outlet hot cyclone to boiler; Structure and platforms, and ladders around PAFBC vessel access and major equipment. Design work is currently in progress on all of the above components. Items 1, 2, 3 and 4 are 50% completed, and items 5 6 are 75% complete.

  20. Battery using a metal particle bed electrode

    DOE Patents [OSTI]

    Evans, James V. (Piedmont, CA); Savaskan, Gultekin (Albany, CA)

    1991-01-01

    A zinc-air battery in a case including a zinc particle bed supported adjacent the current feeder and diaphragm on a porous support plate which holds the particles but passes electrolyte solution. Electrolyte is recycled through a conduit between the support plate and top of the bed by convective forces created by a density of differential caused by a higher concentration of high density discharge products in the interstices of the bed than in the electrolyte recycle conduit.

  1. Battery using a metal particle bed electrode

    DOE Patents [OSTI]

    Evans, J.V.; Savaskan, G.

    1991-04-09

    A zinc-air battery in a case is described including a zinc particle bed supported adjacent the current feeder and diaphragm on a porous support plate which holds the particles but passes electrolyte solution. Electrolyte is recycled through a conduit between the support plate and top of the bed by convective forces created by a density of differential caused by a higher concentration of high density discharge products in the interstices of the bed than in the electrolyte recycle conduit. 7 figures.

  2. Advanced Fluidized Bed Waste Heat Recovery Systems 

    E-Print Network [OSTI]

    Peterson, G. R.

    1988-01-01

    BED WASTE HEAT RECOVERY SYSTEMS G. R. PETERSON Project Manager U.S. Department of Energy, Idaho Operations Office Idaho Falls, Idaho ABSTRACT The U.S. Department of Energy, Office of Industri al Programs, has sponsored the development of a... Fluidized Bed Waste Heat Recovery System (FBWHRS) and a higher temperature variant, the Ceramic Tubular Distributor Plate (CTOP) Fluidized Bed Heat Exchanger (FBHX) system. Both systems recover energy from high-temperature flue gases and produce steam...

  3. Gas distributor for fluidized bed coal gasifier

    DOE Patents [OSTI]

    Worley, Arthur C. (Mt. Tabor, NJ); Zboray, James A. (Irvine, CA)

    1980-01-01

    A gas distributor for distributing high temperature reaction gases to a fluidized bed of coal particles in a coal gasification process. The distributor includes a pipe with a refractory reinforced lining and a plurality of openings in the lining through which gas is fed into the bed. These feed openings have an expanding tapered shape in the downstream or exhaust direction which aids in reducing the velocity of the gas jets as they enter the bed.

  4. Simulation of Fischer-Tropsch Fixed-Bed Reactor in Different Reaction Media 

    E-Print Network [OSTI]

    Bani Nasser, Laial Ahmad

    2013-11-04

    reactor), while simultaneously overcoming their limitations. This work focuses on modeling the behavior in the reactor bed (‘macro-scale’ assessment) and then zooming into the catalyst pellet itself (‘micro-scale’ assessment). The aim of this research...

  5. Evolution of a non-cohesive granular bed subject to a succession of erosive turbidity currents

    E-Print Network [OSTI]

    Rangel, Roberto Carlos

    2006-01-01

    An experiment was performed to study the evolution of a non-cohesive granular bed subject to a succession of erosive turbidity currents to evaluate the applicability of a proposed interface model that prescribes a relationship ...

  6. A new bed elevation dataset for Greenland

    E-Print Network [OSTI]

    2013-01-01

    S. : A new ice thick- ness and bed data set for theto measure ice thick- ness in areas of warm and fractured

  7. Combined fluidized bed retort and combustor

    DOE Patents [OSTI]

    Shang, Jer-Yu (Fairfax, VA); Notestein, John E. (Morgantown, WV); Mei, Joseph S. (Morgantown, WV); Zeng, Li-Wen (Morgantown, WV)

    1984-01-01

    The present invention is directed to a combined fluidized bed retorting and combustion system particularly useful for extracting energy values from oil shale. The oil-shale retort and combustor are disposed side-by-side and in registry with one another through passageways in a partition therebetween. The passageways in the partition are submerged below the top of the respective fluid beds to preclude admixing or the product gases from the two chambers. The solid oil shale or bed material is transported through the chambers by inclining or slanting the fluidizing medium distributor so that the solid bed material, when fluidized, moves in the direction of the downward slope of the distributor.

  8. Packed fluidized bed blanket for fusion reactor

    DOE Patents [OSTI]

    Chi, John W. H. (Mt. Lebanon, PA)

    1984-01-01

    A packed fluidized bed blanket for a fusion reactor providing for efficient radiation absorption for energy recovery, efficient neutron absorption for nuclear transformations, ease of blanket removal, processing and replacement, and on-line fueling/refueling. The blanket of the reactor contains a bed of stationary particles during reactor operation, cooled by a radial flow of coolant. During fueling/refueling, an axial flow is introduced into the bed in stages at various axial locations to fluidize the bed. When desired, the fluidization flow can be used to remove particles from the blanket.

  9. The effect of velocity and porosity profiles on the performance of fixed bed reactors 

    E-Print Network [OSTI]

    Amin, Kaushik

    1983-01-01

    (m r) R. H. Loeppert (member) C. D. 1 and (Head of the Dept. ) December 1983 ABSTRACT THE Effect of Velocity and Porosity Profiles on the Performance of Fixed Bed Reactors (December 1983) Kaushik Amin, B. S. , M. S. University of Barcda... and velocity profiles in the modeling of fixed bed reactors. The first attempt accounting for the porosity profile in the reactor mcdel was made by Xondelik et al. (1969). They used a one dimensional parallel channel model to predict overall conversion...

  10. Hydrological consequences of global warming

    SciTech Connect (OSTI)

    Miller, Norman L.

    2009-06-01

    The 2007 Intergovernmental Panel for Climate Change indicates there is strong evidence that the atmospheric concentration of carbon dioxide far exceeds the natural range over the last 650,000 years, and this recent warming of the climate system is unequivocal, resulting in more frequent extreme precipitation events, earlier snowmelt runoff, increased winter flood likelihoods, increased and widespread melting of snow and ice, longer and more widespread droughts, and rising sea level. The effects of recent warming has been well documented and climate model projections indicate a range of hydrological impacts with likely to very likely probabilities (67 to 99 percent) of occurring with significant to severe consequences in response to a warmer lower atmosphere with an accelerating hydrologic cycle.

  11. Precious Corals in Hawaii: Discovery of a New Bed and Revised Management Measures for Existing Beds

    E-Print Network [OSTI]

    Precious Corals in Hawaii: Discovery of a New Bed and Revised Management Measures for Existing Beds Introduction and History of Hawaii's Precious Coral Fishery Precious corals, Corallium spp., wereTheodore Chamberlain,oftheUniversityofHawaii, discovered a small bed of Corallium Richard W. Grigg (rgrigg@soest.hawaii

  12. Pressure Drop in a Pebble Bed Reactor 

    E-Print Network [OSTI]

    Kang, Changwoo

    2011-10-21

    of the wall effects and porosity can be explained by using different bed-to-particle diameter ratios. Four different bed-to-particle ratios were used in these experiments (D/dp = 19, 9.5, 6.33 and 3.65). A comparison is made between the predictions by a number...

  13. Best Management Practices for Bedding and

    E-Print Network [OSTI]

    Ishida, Yuko

    1 Best Management Practices for Bedding and Container Color Plant Production in California #12;2 Table of Contents Acknowledgements 3 Introduction 4 Current Integrated Pest Management Practices in California Bedding and Container Color Plant Production 5 Best Management Practices for Disease Prevention 16

  14. Fluidized-bed copper oxide process

    SciTech Connect (OSTI)

    Shah, P.P.; Takahashi, G.S.; Leshock, D.G.

    1991-10-14

    The fluidized-bed copper oxide process was developed to simultaneously remove sulfur dioxide and nitrogen oxide contaminants from the flue gas of coal-fired utility boilers. This dry and regenerable process uses a copper oxide sorbent in a fluidized-bed reactor. Contaminants are removed without generating waste material. (VC)

  15. Fluidized-bed combustion fuel

    SciTech Connect (OSTI)

    Rich, J.W. Jr.

    1990-10-09

    This patent describes a process for producing from a solid carbonaceous refuse a high ash fuel for use in a circulating fluidized-bed combustion chamber. It comprises separating from the refuse a carbonaceous portion having an ash content in a selected range percent by weight; separating the carbonaceous portion into first and second fractions, the first fraction being at or above a selected size; crushing the first fraction; and combining the crushed first fraction with the second fraction. Also described is a process wherein the selected ash content range is between about 30 percent and about 50 percent, by weight. Also described is a process wherein the selected size is above about 1/4 inch.

  16. Fluidized bed heat treating system

    DOE Patents [OSTI]

    Ripley, Edward B; Pfennigwerth, Glenn L

    2014-05-06

    Systems for heat treating materials are presented. The systems typically involve a fluidized bed that contains granulated heat treating material. In some embodiments a fluid, such as an inert gas, is flowed through the granulated heat treating medium, which homogenizes the temperature of the heat treating medium. In some embodiments the fluid may be heated in a heating vessel and flowed into the process chamber where the fluid is then flowed through the granulated heat treating medium. In some embodiments the heat treating material may be liquid or granulated heat treating material and the heat treating material may be circulated through a heating vessel into a process chamber where the heat treating material contacts the material to be heat treated. Microwave energy may be used to provide the source of heat for heat treating systems.

  17. Z-Bed Recovery Water Disposal | Department of Energy

    Office of Environmental Management (EM)

    Z-Bed Recovery Water Disposal Z-Bed Recovery Water Disposal Presentation from the 33rd Tritium Focus Group Meeting held in Aiken, South Carolina on April 22-24, 2014. Z-Bed...

  18. MEDICAL ENTOMOLOGY Repellency of Selected Chemicals Against the Bed Bug

    E-Print Network [OSTI]

    Wang, Changlu

    MEDICAL ENTOMOLOGY Repellency of Selected Chemicals Against the Bed Bug (Hemiptera: Cimicidae and bed bug bites. KEY WORDS bed bug, repellent, DEET, natural product, essential oil Since the late 1990s

  19. Simulation of deep-bed drying of Virginia peanuts to minimize energy use

    SciTech Connect (OSTI)

    Kulasiri, G.D.

    1990-01-01

    A deep-bed drying model simulating the drying of peanuts in a fixed bed is required for designing energy-efficient and automatically controlled dryers. A deep-red drying model consists of a thin-layer drying model to calculate the moisture release from the material and a set of mass and energy balances. An experimental setup was constructed to determine drying rates of Virginia-type peanuts under 14 different drying air conditions. Selected empirical and semi-theoretical models available for modeling thin-layer drying rates were fitted to the collected data using nonlinear regression techniques. The modified Page's model and the two-term exponential model fitted the data better than other models considered. A deep-bed drying model PEATECH based on four coupled partial differential equations consisting of four variables, air temperature, peanut temperature, air humidity, and peanut moisture content was developed. Validation of the model was accomplished by using the data collected from 36 deep-bed drying experiments conducted using three laboratory dryers during 1987, 1988, and 1989. PEATECH predicted the variables within a peanut bed with an accuracy of less than {plus minus} 6%. The energy saving potential of exhaust-air recirculation was established by conducting simulated experiments using a modified version of PEATECH.

  20. National SCADA Test Bed - Enhancing control systems security...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    National SCADA Test Bed - Enhancing control systems security in the energy sector (September 2009) National SCADA Test Bed - Enhancing control systems security in the energy sector...

  1. Climate Science for a Sustainable Energy Future Test Bed and Data Infrastructure Final Report

    SciTech Connect (OSTI)

    Williams, Dean N.; Foster, I.; Van Dam, Kerstin Kleese; Shipman, G.

    2014-05-04

    The collaborative Climate Science for a Sustainable Energy Future (CSSEF) project started in July 2011 with the goal of accelerating the development of climate model components (i.e., atmosphere, ocean and sea ice, and land surface) and enhancing their predictive capabilities while incorporating uncertainty quantification (UQ). This effort required accessing and converting observational data sets into specialized model testing and verification data sets and building a model development test bed, where model components and sub-models can be rapidly evaluated. CSSEF’s prototype test bed demonstrated, how an integrated testbed could eliminate tedious activities associated with model development and evaluation, by providing the capability to constantly compare model output—where scientists store, acquire, reformat, regrid, and analyze data sets one-by-one—to observational measurements in a controlled test bed.

  2. Assuring quality in high-consequence engineering

    SciTech Connect (OSTI)

    Hoover, Marcey L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Kolb, Rachel R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-03-01

    In high-consequence engineering organizations, such as Sandia, quality assurance may be heavily dependent on staff competency. Competency-dependent quality assurance models are at risk when the environment changes, as it has with increasing attrition rates, budget and schedule cuts, and competing program priorities. Risks in Sandia's competency-dependent culture can be mitigated through changes to hiring, training, and customer engagement approaches to manage people, partners, and products. Sandia's technical quality engineering organization has been able to mitigate corporate-level risks by driving changes that benefit all departments, and in doing so has assured Sandia's commitment to excellence in high-consequence engineering and national service.

  3. Standleg Moving Granular Bed Filter development program

    SciTech Connect (OSTI)

    Newby, R.A.; Yang, W.C.; Smeltzer, E.E.

    1992-11-01

    The design, fabrication, and installation of the cold flow test facility has been completed. The SMGBF test facility shown in Figure 2 consists of a solids feed hopper, a transparent test vessel, a screw conveyor, a 55-gal drum for solids storage, a dust feeder, a baghouse filter, and the associated instrumentation for flow and pressure control and measurement. The standleg is 11-in ID by 3-ft long, and also transparent to facilitate observation. The crushed acrylic particles of characteristics shown in Table 1 are used as the bed media. The bed particles were selected, by maintaining the particle size while reducing the particle density, to simulate the minimum fluidization velocity expected under high-temperature, high-pressure conditions. By maintaining the particle size, the bed effectively simulates the bed packing and voidage in the moving bed which is directly related to the efficiency of particulate removal and pressure drop characteristics. The test facility performed as designed and no particular difficulties were encountered. The baseline data on pressure profiles across the stationary and the moving granular beds were obtained for gas face velocities up to 6 ft/s, higher than the minimum fluidization velocity of the bed material (5 ft/s), and no visible fluidization was observed at the base of the standleg. This confirms the operational feasibility of the compact SMGBF design.

  4. Standleg Moving Granular Bed Filter development program

    SciTech Connect (OSTI)

    Newby, R.A.; Yang, W.C.; Smeltzer, E.E.

    1992-01-01

    The design, fabrication, and installation of the cold flow test facility has been completed. The SMGBF test facility shown in Figure 2 consists of a solids feed hopper, a transparent test vessel, a screw conveyor, a 55-gal drum for solids storage, a dust feeder, a baghouse filter, and the associated instrumentation for flow and pressure control and measurement. The standleg is 11-in ID by 3-ft long, and also transparent to facilitate observation. The crushed acrylic particles of characteristics shown in Table 1 are used as the bed media. The bed particles were selected, by maintaining the particle size while reducing the particle density, to simulate the minimum fluidization velocity expected under high-temperature, high-pressure conditions. By maintaining the particle size, the bed effectively simulates the bed packing and voidage in the moving bed which is directly related to the efficiency of particulate removal and pressure drop characteristics. The test facility performed as designed and no particular difficulties were encountered. The baseline data on pressure profiles across the stationary and the moving granular beds were obtained for gas face velocities up to 6 ft/s, higher than the minimum fluidization velocity of the bed material (5 ft/s), and no visible fluidization was observed at the base of the standleg. This confirms the operational feasibility of the compact SMGBF design.

  5. Fluidized bed catalytic coal gasification process

    DOE Patents [OSTI]

    Euker, Jr., Charles A. (15163 Dianna La., Houston, TX 77062); Wesselhoft, Robert D. (120 Caldwell, Baytown, TX 77520); Dunkleman, John J. (3704 Autumn La., Baytown, TX 77520); Aquino, Dolores C. (15142 McConn, Webster, TX 77598); Gouker, Toby R. (5413 Rocksprings Dr., LaPorte, TX 77571)

    1984-01-01

    Coal or similar carbonaceous solids impregnated with gasification catalyst constituents (16) are oxidized by contact with a gas containing between 2 volume percent and 21 volume percent oxygen at a temperature between 50.degree. C. and 250.degree. C. in an oxidation zone (24) and the resultant oxidized, catalyst impregnated solids are then gasified in a fluidized bed gasification zone (44) at an elevated pressure. The oxidation of the catalyst impregnated solids under these conditions insures that the bed density in the fluidized bed gasification zone will be relatively high even though the solids are gasified at elevated pressure and temperature.

  6. Mapping the Consequences of Electoral Reform

    E-Print Network [OSTI]

    Latner, Michael S; Roach, Kyle

    2011-01-01

    Consequences of Electoral Reform Table A2. Unrotated Matrixthe Consequences of Electoral Reform California Journal ofConsequences of Electoral Reform Michael S. Latner and Kyle

  7. CERTS Microgrid Laboratory Test Bed

    SciTech Connect (OSTI)

    Lasseter, R. H.; Eto, J. H.; Schenkman, B.; Stevens, J.; Volkmmer, H.; Klapp, D.; Linton, E.; Hurtado, H.; Roy, J.

    2010-06-08

    CERTS Microgrid concept captures the emerging potential of distributed generation using a system approach. CERTS views generation and associated loads as a subsystem or a 'microgrid'. The sources can operate in parallel to the grid or can operate in island, providing UPS services. The system can disconnect from the utility during large events (i.e. faults, voltage collapses), but may also intentionally disconnect when the quality of power from the grid falls below certain standards. CERTS Microgrid concepts were demonstrated at a full-scale test bed built near Columbus, Ohio and operated by American Electric Power. The testing fully confirmed earlier research that had been conducted initially through analytical simulations, then through laboratory emulations, and finally through factory acceptance testing of individual microgrid components. The islanding and resynchronization method met all Institute of Electrical and Electronics Engineers Standard 1547 and power quality requirements. The electrical protection system was able to distinguish between normal and faulted operation. The controls were found to be robust under all conditions, including difficult motor starts and high impedance faults.

  8. Z-Bed Recovery Water Disposal

    Office of Environmental Management (EM)

    Z-Bed Recovery Water Disposal Tritium Programs Engineering Louis Boone Josh Segura Savannah River Nuclear Solutions, LLC M-TRT-H-00087 Rev 0 Date: 4102014 Tritium Facilities...

  9. Methanol synthesis in a trickle bed reactor 

    E-Print Network [OSTI]

    Tjandra, Sinoto

    1992-01-01

    the heat of reaction for synthesis of liquid fuels from CO and H2. At present, they are used primarily in the petroleum industries for hydrodenitrogenation, hydrodesulfurization and hydrocracking. Other commercial applications of trickle bed reactors...

  10. Fluid Bed Combustion Applied to Industrial Waste 

    E-Print Network [OSTI]

    Mullen, J. F.; Sneyd, R. J.

    1985-01-01

    Because of its unique ability to handle a wide variety of liquids and solids in an energy efficient and environmentally acceptable manner, fluid bed combustion is being increasingly applied to the utilization of waste materials and low grade fuels...

  11. Fluidized Bed Technology - Overview | Department of Energy

    Energy Savers [EERE]

    fluidized bed boilers as a standard package. This success is largely due to the Clean Coal Technology Program and the Energy Department's Fossil Energy and industry partners R&D....

  12. Fluidized bed injection assembly for coal gasification

    DOE Patents [OSTI]

    Cherish, Peter (Bethel Park, PA); Salvador, Louis A. (Hempfield Township, Westmoreland County, PA)

    1981-01-01

    A coaxial feed system for fluidized bed coal gasification processes including an inner tube for injecting particulate combustibles into a transport gas, an inner annulus about the inner tube for injecting an oxidizing gas, and an outer annulus about the inner annulus for transporting a fluidizing and cooling gas. The combustibles and oxidizing gas are discharged vertically upward directly into the combustion jet, and the fluidizing and cooling gas is discharged in a downward radial direction into the bed below the combustion jet.

  13. Coal-Fired Fluidized Bed Combustion Cogeneration 

    E-Print Network [OSTI]

    Thunem, C.; Smith, N.

    1985-01-01

    BED COMBUSTION COGENERATION Cabot Thunem, P.E Norm Smith, P.E. Stanley Consultants, Inc. Muscatine, Iowa ABSTRACT The availability of an environmentally accep table multifuel technology, such as fluidized bed combustion, has encouraged many... steam producers/ users to investigate switching from oil or gas to coal. Changes in federal regulations encouraging cogeneration have further enhanced the economic incentives for primary fuel switching. However, this addition of cogeneration...

  14. Numerical simulation of ceramic breeder pebble bed thermal creep behavior

    E-Print Network [OSTI]

    Abdou, Mohamed

    Numerical simulation of ceramic breeder pebble bed thermal creep behavior Alice Ying *, Hulin Huang Abstract The evolution of ceramic breeder pebble bed thermal creep deformation subjected to an external of ceramic breeder pebble beds under thermomechanical loads is necessary to ensure that the integrity of beds

  15. Forecasting Hospital Bed Availability Using Simulation and Neural Networks

    E-Print Network [OSTI]

    Kuhl, Michael E.

    Forecasting Hospital Bed Availability Using Simulation and Neural Networks Matthew J. Daniels, NY 14623 Elisabeth Hager Hager Consulting Pittsford, NY 14534 Abstract The availability of beds is a critical factor for decision-making in hospitals. Bed availability (or alternatively the bed occupancy

  16. Effect of sediment pulse grain size on sediment transport rates and bed mobility in gravel bed rivers

    E-Print Network [OSTI]

    Venditti, Jeremy G.

    Effect of sediment pulse grain size on sediment transport rates and bed mobility in gravel bed] Sediment supply to gravel bed river channels often takes the form of episodic sediment pulses, and there is considerable interest in introducing sediment pulses in stream restorations to alter bed surface grain size

  17. Enhanced Productivity of Chemical Processes Using Dense Fluidized Beds

    SciTech Connect (OSTI)

    Sibashis Banerjee; Alvin Chen; Rutton Patel; Dale Snider; Ken Williams; Timothy O'Hern; Paul Tortora

    2008-02-29

    The work detailed in this report addresses Enabling Technologies within Computational Technology by integrating a “breakthrough” particle-fluid computational technology into traditional Process Science and Engineering Technology. The work completed under this DOE project addresses five major development areas 1) gas chemistry in dense fluidized beds 2) thermal cracking of liquid film on solids producing gas products 3) liquid injection in a fluidized bed with particle-to-particle liquid film transport 4) solid-gas chemistry and 5) first level validation of models. Because of the nature of the research using tightly coupled solids and fluid phases with a Lagrangian description of the solids and continuum description of fluid, the work provides ground-breaking advances in reactor prediction capability. This capability has been tested against experimental data where available. The commercial product arising out of this work is called Barracuda and is suitable for a wide (dense-to-dilute) range of industrial scale gas-solid flows with and without reactions. Commercial applications include dense gas-solid beds, gasifiers, riser reactors and cyclones.

  18. Ash bed level control system for a fixed-bed coal gasifier

    DOE Patents [OSTI]

    Fasching, George E. (Morgantown, WV); Rotunda, John R. (Fairmont, WV)

    1984-01-01

    An ash level control system is provided which incorporates an ash level meter to automatically control the ash bed level of a coal gasifier at a selected level. The ash level signal from the ash level meter is updated during each cycle that a bed stirrer travels up and down through the extent of the ash bed level. The ash level signal is derived from temperature measurements made by thermocouples carried by the stirrer as it passes through the ash bed and into the fire zone immediately above the ash bed. The level signal is compared with selected threshold level signal to determine if the ash level is above or below the selected level once each stirrer cycle. A first counter is either incremented or decremented accordingly. The registered count of the first counter is preset in a down counter once each cycle and the preset count is counted down at a selected clock rate. A grate drive is activated to rotate a grate assembly supporting the ash bed for a period equal to the count down period to maintain the selected ash bed level. In order to avoid grate binding, the controller provides a short base operating duration time each stirrer cycle. If the ash bed level drops below a selected low level or exceeds a selected high level, means are provided to notify the operator.

  19. Fluid bed gasification – Plasma converter process generating energy from solid waste: Experimental assessment of sulphur species

    SciTech Connect (OSTI)

    Morrin, Shane, E-mail: shane.morrin@ucl.ac.uk [Department of Chemical Engineering, University College London, London WC1E 7JE (United Kingdom); Advanced Plasma Power, Swindon, Wiltshire SN3 4DE (United Kingdom); Lettieri, Paola, E-mail: p.lettieri@ucl.ac.uk [Department of Chemical Engineering, University College London, London WC1E 7JE (United Kingdom); Chapman, Chris, E-mail: chris.chapman@app-uk.com [Advanced Plasma Power, Swindon, Wiltshire SN3 4DE (United Kingdom); Taylor, Richard, E-mail: richard.taylor@app-uk.com [Advanced Plasma Power, Swindon, Wiltshire SN3 4DE (United Kingdom)

    2014-01-15

    Highlights: • We investigate gaseous sulphur species whilst gasifying sulphur-enriched wood pellets. • Experiments performed using a two stage fluid bed gasifier – plasma converter process. • Notable SO{sub 2} and relatively low COS levels were identified. • Oxygen-rich regions of the bed are believed to facilitate SO{sub 2}, with a delayed release. • Gas phase reducing regions above the bed would facilitate more prompt COS generation. - Abstract: Often perceived as a Cinderella material, there is growing appreciation for solid waste as a renewable content thermal process feed. Nonetheless, research on solid waste gasification and sulphur mechanisms in particular is lacking. This paper presents results from two related experiments on a novel two stage gasification process, at demonstration scale, using a sulphur-enriched wood pellet feed. Notable SO{sub 2} and relatively low COS levels (before gas cleaning) were interesting features of the trials, and not normally expected under reducing gasification conditions. Analysis suggests that localised oxygen rich regions within the fluid bed played a role in SO{sub 2}’s generation. The response of COS to sulphur in the feed was quite prompt, whereas SO{sub 2} was more delayed. It is proposed that the bed material sequestered sulphur from the feed, later aiding SO{sub 2} generation. The more reducing gas phase regions above the bed would have facilitated COS – hence its faster response. These results provide a useful insight, with further analysis on a suite of performed experiments underway, along with thermodynamic modelling.

  20. Experimental investigation of bubbling in particle beds with high solid holdup

    SciTech Connect (OSTI)

    Cheng, Songbai; Hirahara, Daisuke; Tanaka, Youhei; Gondai, Yoji; Zhang, Bin; Matsumoto, Tatsuya; Morita, Koji; Fukuda, Kenji; Yamano, Hidemasa; Suzuki, Tohru; Tobita, Yoshiharu

    2011-02-15

    A series of experiments on bubbling behavior in particle beds was performed to clarify three-phase flow dynamics in debris beds formed after core-disruptive accident (CDA) in sodium-cooled fast breeder reactors (FBRs). Although in the past, several experiments have been performed in packed beds to investigate flow patterns, most of these were under comparatively higher gas flow rate, which may be not expected during an early sodium boiling period in debris beds. The current experiments were conducted under two dimensional (2D) and three dimensional (3D) conditions separately, in which water was used as liquid phase, and bubbles were generated by injecting nitrogen gas from the bottom of the viewing tank. Various particle-bed parameters were varied, including particle-bed height (from 30 mm to 200 mm), particle diameter (from 0.4 mm to 6 mm) and particle type (beads made of acrylic, glass, alumina and zirconia). Under these experimental conditions, three kinds of bubbling behavior were observed for the first time using digital image analysis methods that were further verified by quantitative detailed analysis of bubbling properties including surface bubbling frequency and surface bubble size under both 2D and 3D conditions. This investigation, which hopefully provides fundamental data for a better understanding and an improved estimation of CDAs in FBRs, is expected to benefit future analysis and verification of computer models developed in advanced fast reactor safety analysis codes. (author)

  1. Fluidized bed selective pyrolysis of coal

    DOE Patents [OSTI]

    Shang, J.Y.; Cha, C.Y.; Merriam, N.W.

    1992-12-15

    The present invention discloses a process for the pyrolysis of coal which comprises the effective utilization of two zonal inclined fluidized beds, where said zones can be selectively controlled as to temperature and heating rate. The first zonal inclined fluidized bed serves as a dryer for crushed coal and additionally is controlled to selectively pyrolyze said coal producing substantially carbon dioxide for recycle use. The second zonal inclined fluidized bed further pyrolyses the coal to gaseous, liquid and char products under controlled temperature and heating rate zones designed to economically integrate the product mix. The gas and liquid products are recovered from the gaseous effluent stream while the char which remains can be further treated or utilized in a subsequent process step. 9 figs.

  2. Fluidized bed selective pyrolysis of coal

    DOE Patents [OSTI]

    Shang, Jer Y. (McLean, VA); Cha, Chang Y. (Golden, CO); Merriam, Norman W. (Laramie, WY)

    1992-01-01

    The present invention discloses a process for the pyrolysis of coal which comprises the effective utilization of two zonal inclined fluidized beds, where said zones can be selectively controlled as to temperature and heating rate. The first zonal inclined fluidized bed serves as a dryer for crushed coal and additionally is controlled to selectively pyrolyze said coal producing substantially carbon dioxide for recycle use. The second zonal inclined fluidized bed further pyrolyzes the coal to gaseous, liquid and char products under controlled temperature and heating rate zones designed to economically integrate the product mix. The gas and liquid products are recovered from the gaseous effluent stream while the char which remains can be further treated or utilized in a subsequent process step.

  3. Particle withdrawal from fluidized bed systems

    DOE Patents [OSTI]

    Salvador, Louis A. (Greensburg, PA); Andermann, Ronald E. (Arlington Heights, IL); Rath, Lawrence K. (Mt. Pleasant, PA)

    1982-01-01

    Method and apparatus for removing ash formed within, and accumulated at the lower portion of, a fluidized bed coal gasification reactor vessel. A supplemental fluidizing gas, at a temperature substantially less than the average fluidized bed combustion operating temperature, is injected into the vessel and upwardly through the ash so as to form a discrete thermal interface region between the fluidized bed and the ash. The elevation of the interface region, which rises with ash accumulation, is monitored by a thermocouple and interrelated with a motor controlled outlet valve. When the interface rises above the temperature indicator, the valve opens to allow removal of some of the ash, and the valve is closed, or positioned at a minimum setting, when the interface drops to an elevation below that of the thermocouple.

  4. 3-D capacitance density imaging of fluidized bed

    DOE Patents [OSTI]

    Fasching, George E. (653 Vista Pl., Morgantown, WV 26505)

    1990-01-01

    A three-dimensional capacitance density imaging of a gasified bed or the like in a containment vessel is achieved using a plurality of electrodes provided circumferentially about the bed in levels and along the bed in channels. The electrodes are individually and selectively excited electrically at each level to produce a plurality of current flux field patterns generated in the bed at each level. The current flux field patterns are suitably sensed and a density pattern of the bed at each level determined. By combining the determined density patterns at each level, a three-dimensional density image of the bed is achieved.

  5. High temperature degradation by erosion-corrosion in bubbling fluidized bed combustors

    E-Print Network [OSTI]

    Hou, Peggy Y.; MacAdam, S.; Niu, Y.; Stringer, J.

    2003-01-01

    a Laboratory Simulated Bubbling Fluidized Bed", Wear. 235,Tube Wastage in Bubbling Fluidized Bed, a Laboratory StudyWheeldon, "Wastage in bubbling fluidized-bed combustors: an

  6. An experimental study of a vertical tube gas-fluidized bed

    E-Print Network [OSTI]

    Mandich, Kevin Matthew

    2010-01-01

    Temperature in a Bubbling Fluidized Bed: Simulations andfluidized bed of hollow microparticles prior to onset of bubbling.to the bubbling regime of the fluidized bed, while the

  7. Particle simulation of vibrated gas-fluidized beds of cohesive fine powders

    E-Print Network [OSTI]

    Sung Joon Moon; I. G. Kevrekidis; S. Sundaresan

    2006-08-09

    We use three-dimensional particle dynamics simulations, coupled with volume-averaged gas phase hydrodynamics, to study vertically vibrated gas-fluidized beds of fine, cohesive powders. The volume-averaged interstitial gas flow is restricted to be one-dimensional (1D). This simplified model captures the spontaneous development of 1D traveling waves, which corresponds to bubble formation in real fluidized beds. We use this model to probe the manner in which vibration and gas flow combine to influence the dynamics of cohesive particles. We find that as the gas flow rate increases, cyclic pressure pulsation produced by vibration becomes more and more significant than direct impact, and in a fully fluidized bed this pulsation is virtually the only relevant mechanism. We demonstrate that vibration assists fluidization by creating large tensile stresses during transient periods, which helps break up the cohesive assembly into agglomerates.

  8. Fluidized bed electrowinning of copper. Final report

    SciTech Connect (OSTI)

    1997-07-01

    The objectives of the study were to: design and construct a 10,000- amp fluidized bed electrowinning cell for the recovery of copper from acidic sulfate solutions; demonstrate the technical feasibility of continuous particle recirculation from the electrowinning cell with the ultimate goal of continuous particle removal; and measure cell efficiency as a function of operating conditions.

  9. Pebble Flow Experiments For Pebble Bed Reactors

    E-Print Network [OSTI]

    Pebble Flow Experiments For Pebble Bed Reactors Andrew C. Kadak1 Department of Nuclear Engineering of Technology 2nd International Topical Meeting on High Temperature Reactor Technology Institute of Nuclear was that the draining of the pebbles in such a reactor would conform to granular flow theory which suggested rapid

  10. Biogeochemistry of Microbial Coal-Bed Methane

    E-Print Network [OSTI]

    Macalady, Jenn

    Biogeochemistry of Microbial Coal-Bed Methane Dariusz Strapo´c,1, Maria Mastalerz,2 Katherine, biodegradation Abstract Microbial methane accumulations have been discovered in multiple coal- bearing basins low-maturity coals with predominantly microbial methane gas or uplifted coals containing older

  11. Modularity Approach Modular Pebble Bed Reactor (MPBR)

    E-Print Network [OSTI]

    NED MPBR 1150 MW Combined Heat and Power Station Turbine Hall Boundary Admin Training Control Bldg. · No Reprocessing · High Burnup >90,000 Mwd/MT · Direct Disposal of HLW · Process Heat Applications - Hydrogen · On--line Refueling #12;4/23/03 MIT NED MPBR Reference Plant Modular Pebble Bed Reactor Thermal Power

  12. 138 Chemical Engineering Education FLUIDIZED BED

    E-Print Network [OSTI]

    Hesketh, Robert

    138 Chemical Engineering Education FLUIDIZED BED POLYMER COATING EXPERIMENT ROBERT P. HESKETH, C,2] and is a highly visual experiment in chemical engineering pro- cesses and experimentation. In addition for the chemical engineering profession. The field encom- passes many technologies, ranging from polymerization

  13. Pebble Flow Experiments For Pebble Bed Reactors

    E-Print Network [OSTI]

    Bazant, Martin Z.

    of Technology 2nd International Topical Meeting on High Temperature Reactor Technology Institute of NuclearPebble Flow Experiments For Pebble Bed Reactors Andrew C. Kadak1 Department of Nuclear Engineering Massachusetts Institute of Technology Martin Z. Bazant Department of Mathematics Massachusetts Institute

  14. October 2012 Cyber Security Test Bed

    E-Print Network [OSTI]

    McShea, Daniel W.

    1 October 2012 Cyber Security Test Bed Project Leads Brent Rowe, RTI International The inadequacy of U.S. small and medium businesses' cyber security poses great risk to these businesses and to all U.S. organizations and individuals.1 To test strategies for improving the level of cyber security

  15. Advances in Design of the Next Generation Hydride Bed | Department...

    Office of Environmental Management (EM)

    Design of the Next Generation Hydride Bed Advances in Design of the Next Generation Hydride Bed Presentation from the 32nd Tritium Focus Group Meeting held in Germantown, Maryland...

  16. On-Site Wastewater Treatment Systems: Evapotranspiration Bed 

    E-Print Network [OSTI]

    Lesikar, Bruce J.

    1999-09-01

    Evapotranspiration (ET) beds treat wastewater in the soil by evaporation and by transpiration from plants growing there. This publication explains the treatment, design, operation and maintenance of ET beds....

  17. Arrayed microfluidic actuation for active sorting of fluid bed particulates

    E-Print Network [OSTI]

    Gerhardt, Antimony L

    2004-01-01

    Fluidic actuation offers a facile method to move large quantities of small solids, often referred to as fluid-bed movement. Applications for fluid bed processing are integral to many fields including petrochemical, petroleum, ...

  18. Experimental and computational studies of hydrodynamics in three-phase and two-phase fluidized beds

    SciTech Connect (OSTI)

    Bahary, M.

    1994-12-01

    The objective of the present study was to investigate the hydrodynamics of three-phase fluidized beds, their rheology, and experimentally verify a predictive three fluid hydrodynamic model developed at the Illinois Institute of Technology, Chicago. The recent reviews show that there exist no such models in the literature. The IIT hydrodynamic model computes the phase velocities and the volume fractions of gas, liquid, and particulate phases. Model verification involves a comparison of these computed velocities and volume fractions to experimental values. In this thesis, a three fluid model is presented. The input into the model can be particulate viscosities either measured with a Brookfield viscometer or derived using the mathematical techniques of kinetic theory of granular flows pioneered by Savage and others. The computer simulation of a three-phase fluidized bed in an asymmetric mode qualitatively predicts the gas, liquid and solid hold-ups (volume fractions) and flow patterns in the industrially important churn-turbulent (bubbly coalesced) regimes. The computations in a fluidized bed with a symmetric distributor incorrectly showed no bubble coalescence. A combination of X-ray and {gamma}-ray densitometers was used to measure the solids and the liquid volume fractions in a two dimensional bed in the bubble coalesced regime. There is a good agreement between the theory for an asymmetric distributor and the experiments.

  19. Method of feeding particulate material to a fluidized bed

    DOE Patents [OSTI]

    Borio, Richard W. (Somers, CT); Goodstine, Stephen L. (Windsor, CT)

    1984-01-01

    A centrifugal spreader type feeder that supplies a mixture of particulate limestone and coal to the top of a fluidized bed reactor having a flow of air upward therethrough. Large particles of particulate matter are distributed over the upper surface of the bed to utilize the natural mixing within the bed, while fine particles are adapted to utilize an independent feeder that separates them from the large particles and injects them into the bed.

  20. Heat transfer rates in fixed bed catalytic reactors 

    E-Print Network [OSTI]

    Levelton, Bruce Harding

    1951-01-01

    bed. A consideration of thermal effects in a gas-solid tubular reactor involves a number of prime variables, viz. (a) Reynolds number and heat capacity of reactants (b) Tube diameter and length (c) Catalyst particle size, shape and characteristics... conditions than in fixed bed reactors prevail. The problem of determining temperatures in moving-bed catalytic reactors is somewhat similar to that in gas-solid fixed bed reactors, but this investigation will not treat such cases. The mechanism of heat...

  1. Physical Consequences of Mathematical Principles

    E-Print Network [OSTI]

    E. Comay

    2009-07-31

    Physical consequences are derived from the following mathematical structures: the variational principle, Wigner's classifications of the irreducible representations of the Poincare group and the duality invariance of the homogeneous Maxwell equations. The analysis is carried out within the validity domain of special relativity. Hierarchical relations between physical theories are used. Some new results are pointed out together with their comparison with experimental data. It is also predicted that a genuine Higgs particle will not be detected.

  2. Heat exchanger support apparatus in a fluidized bed

    DOE Patents [OSTI]

    Lawton, Carl W. (West Hartford, CT)

    1982-01-01

    A heat exchanger is mounted in the upper portion of a fluidized combusting bed for the control of the temperature of the bed. A support, made up of tubes, is extended from the perforated plate of the fluidized bed up to the heat exchanger. The tubular support framework for the heat exchanger has liquid circulated therethrough to prevent deterioration of the support.

  3. Analysis/control of in-bed tube erosion phenomena in the fluidized bed combustion system. Final technical report

    SciTech Connect (OSTI)

    Lee, Seong W.

    1996-11-01

    Research is presented on erosion and corrosion of fluidized bed combustor component materials. The characteristics of erosion of in-bed tubes was investigated. Anti-corrosion measures were also evaluated.

  4. Solids circulation around a jet in a fluidized bed gasifier. Final technical report, September 1, 1978-September 30, 1980

    SciTech Connect (OSTI)

    Gidaspow, D.; Ettehadieh, B.; Lin, C.; Goyal, A.; Lyczkowski, R.W.

    1980-01-01

    The object of this investigation was to develop an experimentally verified hydrodynamic model to predict solids circulation around a jet in a fluidized bed gasifier. Hydrodynamic models of fluidization use the principles of conservation of mass, momentum and energy. To account for unequal velocities of solid and fluid phases, separate phase momentum balances are developed. Other fluid bed models used in the scale-up of gasifiers do not employ the principles of conservation of momentum. Therefore, these models cannot predict fluid and particle motion. In such models solids mixing is described by means of empirical transfer coefficients. A two dimensional unsteady state computer code was developed to give gas and solid velocities, void fractions and pressure in a fluid bed with a jet. The growth, propagation and collapse of bubbles was calculated. Time-averaged void fractions were calculated that showed an agreement with void fractions measured with a gamma ray densitometer. Calculated gas and solid velocities in the jet appeared to be reasonable. Pressure and void oscillations also appear to be reasonable. A simple analytical formula for the rate of solids circulation was developed from the equations of change. It agrees with Westinghouse fluidization data in a bed with a draft tube. One dimensional hydrodynamic models were applied to modeling of entrained-flow coal gasification reactors and compared with data. Further development of the hydrodynamic models should make the scale-up and simulation of fluidized bed reactors a reality.

  5. Possibility of separation of deuterium from natural hydrogen by a palladium particle bed

    SciTech Connect (OSTI)

    Fukada, Satoshi; Fujiwara, Hiroshi

    1999-08-01

    Deuterium in natural hydrogen can be successfully concentrated by means of frontal chromatography using a Pd particle bed at room temperature. The deuterium concentration at the outlet reaches a maximum immediately after hydrogen breaks through the bed. The outlet concentration curve is correlated to a unified profile based on the plate model regardless of the gaseous flow rate and the inlet deuterium concentration. The height equivalent to a theoretical plate, HETP, decreases from 7.6 to 4.7 mm with an increase of the flow rate from 15 to 87 mL(NTP)/min.

  6. Numerical Analysis on the Generation of Equilibrium Aeolian Sedimentary Bed-Forms From Random Surfaces 

    E-Print Network [OSTI]

    Tankala, Chandan

    2012-10-19

    is a rough sand surface. The numerical model is applied to study the effect of varying the angle, at which the sand bed gets impacted by sand grains, on the evolution of ripples. Ripples are analyzed qualitatively and quantitatively by considering...

  7. Fluidized bed gasification of extracted coal

    DOE Patents [OSTI]

    Aquino, Dolores C. (Houston, TX); DaPrato, Philip L. (Westfield, NJ); Gouker, Toby R. (Baton Rouge, LA); Knoer, Peter (Houston, TX)

    1986-01-01

    Coal or similar carbonaceous solids are extracted by contacting the solids in an extraction zone (12) with an aqueous solution having a pH above 12.0 at a temperature between 65.degree. C. and 110.degree. C. for a period of time sufficient to remove bitumens from the coal into said aqueous solution and the extracted solids are then gasified at an elevated pressure and temperature in a fluidized bed gasification zone (60) wherein the density of the fluidized bed is maintained at a value above 160 kg/m.sup.3. In a preferred embodiment of the invention, water is removed from the aqueous solution in order to redeposit the extracted bitumens onto the solids prior to the gasification step.

  8. Fluidized bed gasification of extracted coal

    DOE Patents [OSTI]

    Aquino, D.C.; DaPrato, P.L.; Gouker, T.R.; Knoer, P.

    1984-07-06

    Coal or similar carbonaceous solids are extracted by contacting the solids in an extraction zone with an aqueous solution having a pH above 12.0 at a temperature between 65/sup 0/C and 110/sup 0/C for a period of time sufficient to remove bitumens from the coal into said aqueous solution, and the extracted solids are then gasified at an elevated pressure and temperature in a fluidized bed gasification zone (60) wherein the density of the fluidized bed is maintained at a value above 160 kg/m/sup 3/. In a preferred embodiment of the invention, water is removed from the aqueous solution in order to redeposit the extracted bitumens onto the solids prior to the gasification step. 2 figs., 1 tab.

  9. Fluidized bed boiler having a segmented grate

    DOE Patents [OSTI]

    Waryasz, Richard E. (Longmeadow, MA)

    1984-01-01

    A fluidized bed furnace (10) is provided having a perforate grate (9) within a housing which supports a bed of particulate material including some combustibles. The grate is divided into a plurality of segments (E2-E6, SH1-SH5, RH1-RH5), with the airflow to each segment being independently controlled. Some of the segments have evaporating surface imbedded in the particulate material above them, while other segments are below superheater surface or reheater surface. Some of the segments (E1, E7) have no surface above them, and there are ignitor combustors (32, 34) directed to fire into the segments, for fast startup of the furnace without causing damage to any heating surface.

  10. Pulsed atmospheric fluidized bed combustion. Final report

    SciTech Connect (OSTI)

    NONE

    1998-03-01

    ThermoChem, under contract to the Department of Energy, conducted extensive research, development and demonstration work on a Pulsed Atmospheric Fluidized Bed Combustor (PAFBC) to confirm that advanced technology can meet these performance objectives. The ThermoChem/MTCI PAFBC system integrates a pulse combustor with an atmospheric bubbling-bed type fluidized bed combustor (BFBC) In this modular configuration, the pulse combustor burns the fuel fines (typically less than 30 sieve or 600 microns) and the fluidized bed combusts the coarse fuel particles. Since the ThermoChem/MTCI PAFBC employs both the pulse combustor and the AFBC technologies, it can handle the full-size range of coarse and fines. The oscillating flow field in the pulse combustor provides for high interphase and intraparticle mass transfer rates. Therefore, the fuel fines essentially burn under kinetic control. Due to the reasonably high temperature (>1093 C but less than the temperature for ash fusion to prevent slagging), combustion of fuel fines is substantially complete at the exit of the pulse combustor. The additional residence time of 1 to 2 seconds in the freeboard of the PAFBC unit then ensures high carbon conversion and, in turn, high combustion efficiency. A laboratory unit was successfully designed, constructed and tested for over 600 hours to confirm that the PAFBC technology could meet the performance objectives. Subsequently, a 50,000 lb/hr PAFBC demonstration steam boiler was designed, constructed and tested at Clemson University in Clemson, South Carolina. This Final Report presents the detailed results of this extensive and successful PAFBC research, development and demonstration project.

  11. Reducing mode circulating fluid bed combustion

    DOE Patents [OSTI]

    Lin, Yung-Yi (Katy, TX); Sadhukhan, Pasupati (Katy, TX); Fraley, Lowell D. (Sugarland, TX); Hsiao, Keh-Hsien (Houston, TX)

    1986-01-01

    A method for combustion of sulfur-containing fuel in a circulating fluid bed combustion system wherein the fuel is burned in a primary combustion zone under reducing conditions and sulfur captured as alkaline sulfide. The reducing gas formed is oxidized to combustion gas which is then separated from solids containing alkaline sulfide. The separated solids are then oxidized and recycled to the primary combustion zone.

  12. Pulsed atmospheric fluidized bed combustor apparatus

    DOE Patents [OSTI]

    Mansour, Momtaz N. (Columbia, MD)

    1993-10-26

    A pulsed atmospheric fluidized bed reactor system is disclosed and claimed along with a process for utilization of same for the combustion of, e.g. high sulfur content coal. The system affords a economical, ecologically acceptable alternative to oil and gas fired combustors. The apparatus may also be employed for endothermic reaction, combustion of waste products, e.g., organic and medical waste, drying materials, heating air, calcining and the like.

  13. Status of the fluidized bed unit

    SciTech Connect (OSTI)

    Williams, P.M.; Wade, J.F.

    1994-06-01

    Rocky Flats has a serious mixed waste problem. No technology or company has a license and available facilities to remedy this dilemma. One solution under study is to use a catalytic fluidized bed unit to destroy the combustible portion of the mixed waste. The fluidized bed thermal treatment program at Rocky Flats is building on knowledge gained over twenty years of successful development activity. The FBU has numerous technical advantages over other thermal technologies to treat Rocky Flats` mixed waste, the largest being the lower temperature (700{degrees}C versus 1000{degrees}C) which reduces acid corrosion and mechanical failures and obviates the need for ceramic lining. Successful demonstrations have taken place on bench, pilot, and full-scale tests using radioactive mixed wastes. The program is approaching implementation and licensing of a production-scale fluidized bed system for the safe treatment of mixed waste. The measure for success on this project is the ability to work closely with the community to jointly solve problems and respond to concerns of mixed waste treatment at Rocky Flats.

  14. Some parametric flow analyses of a particle bed fuel element

    SciTech Connect (OSTI)

    Dobranich, D.

    1993-05-01

    Parametric calculations are performed, using the SAFSIM computer program, to investigate the fluid mechanics and heat transfer performance of a particle bed fuel element. Both steady-state and transient calculations are included, addressing such issues as flow stability, reduced thrust operation, transpiration drag, coolant conductivity enhancement, flow maldistributions, decay heat removal, flow perturbations, and pulse cooling. The calculations demonstrate the dependence of the predicted results on the modeling assumptions and thus provide guidance as to where further experimental and computational investigations are needed. The calculations also demonstrate that both flow instability and flow maldistribution in the fuel element are important phenomena. Furthermore, results are encouraging that geometric design changes to the element can significantly reduce problems related to these phenomena, allowing improved performance over a wide range of element power densities and flow rates. Such design changes will help to maximize the operational efficiency of space propulsion reactors employing particle bed fuel element technology. Finally, the results demonstrate that SAFSIM is a valuable engineering tool for performing quick and inexpensive parametric simulations addressing complex flow problems.

  15. In-bed tube bank for a fluidized-bed combustor

    DOE Patents [OSTI]

    Hemenway, Jr., Lloyd F. (Morgantown, WV)

    1990-01-01

    An in-bed tube bank (10) for a fluidized bed combustor. The tube bank (10) of the present invention comprises one or more fluid communicating boiler tubes (30) which define a plurality of selectively spaced boiler tube sections (32). The tube sections (32) are substantially parallel to one another and aligned in a common plane. The tube bank (10) further comprises support members (34) for joining adjacent tube sections (32), the support members (34) engaging and extending along a selected length of the tube sections (32) and spanning the preselected space therebetween.

  16. Investigation of Fuel Chemistry and Bed Performance in a Fluidized Bed Black Liquor Steam Reformer

    SciTech Connect (OSTI)

    Kevin Whitty

    2007-06-30

    University of Utah's project entitled 'Investigation of Fuel Chemistry and Bed Performance in a Fluidized Bed Black Liquor Steam Reformer' (DOE Cooperative Agreement DE-FC26-02NT41490) was developed in response to a solicitation released by the U.S. Department of Energy in December 2001, requesting proposals for projects targeted towards black liquor/biomass gasification technology support research and development. Specifically, the solicitation was seeking projects that would provide technical support for Department of Energy supported black liquor and biomass gasification demonstration projects under development at the time.

  17. The causes and consequences of tax policy

    E-Print Network [OSTI]

    Weller, Nicholas William

    2008-01-01

    OF CALIFORNIA, SAN DIEGO The Causes and Consequences of TaxOF THE DISSERTATION The Causes and Consequences of Taxif ideology is about the causes of voting depending on the

  18. Consequence Management | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Consequence Management | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing Proliferation Powering the...

  19. Anticipating the unintended consequences of security dynamics.

    SciTech Connect (OSTI)

    Backus, George A.; Overfelt, James Robert; Malczynski, Leonard A.; Saltiel, David H.; Simon Paul Moulton

    2010-01-01

    In a globalized world, dramatic changes within any one nation causes ripple or even tsunamic effects within neighbor nations and nations geographically far removed. Multinational interventions to prevent or mitigate detrimental changes can easily cause secondary unintended consequences more detrimental and enduring than the feared change instigating the intervention. This LDRD research developed the foundations for a flexible geopolitical and socioeconomic simulation capability that focuses on the dynamic national security implications of natural and man-made trauma for a nation-state and the states linked to it through trade or treaty. The model developed contains a database for simulating all 229 recognized nation-states and sovereignties with the detail of 30 economic sectors including consumers and natural resources. The model explicitly simulates the interactions among the countries and their governments. Decisions among governments and populations is based on expectation formation. In the simulation model, failed expectations are used as a key metric for tension across states, among ethnic groups, and between population factions. This document provides the foundational documentation for the model.

  20. Hydrodynamic aspects of a circulating fluidized bed with internals

    SciTech Connect (OSTI)

    Balasubramanian, N.; Srinivasakannan, C.

    1998-06-01

    An attempt is made to examine the influence of internals (baffles) in the riser of the circulating fluidized bed. Experiments are conducted in a circulating fluidized bed, having perforated plates with different free areas. It is noticed from the present work that a circulating fluidized bed having 45% free area gives uniform solids concentration and pressure drop along the length of the riser. In addition to the uniformity, the circulating fluidized bed with internals gives higher pressure drop (solids concentration) compared to a conventional circulating fluidized bed. For internals having 67.6% free area the pressure drop is higher at the lower portion of the riser compared to the upper portion, similar to a conventional circulating fluidized bed. For 30% free area plates the solids concentration varies axially within the stage and remains uniform from stage to stage.

  1. Pyrolysis reactor and fluidized bed combustion chamber

    DOE Patents [OSTI]

    Green, Norman W. (Upland, CA)

    1981-01-06

    A solid carbonaceous material is pyrolyzed in a descending flow pyrolysis reactor in the presence of a particulate source of heat to yield a particulate carbon containing solid residue. The particulate source of heat is obtained by educting with a gaseous source of oxygen the particulate carbon containing solid residue from a fluidized bed into a first combustion zone coupled to a second combustion zone. A source of oxygen is introduced into the second combustion zone to oxidize carbon monoxide formed in the first combustion zone to heat the solid residue to the temperature of the particulate source of heat.

  2. Wood fuel in fluidized bed boilers

    SciTech Connect (OSTI)

    Virr, M.J.

    1982-01-01

    Development of fluidized bed fire-tube and water-tube boilers for the burning of wood, gas, and refuse-derived fuel will be reviewed. Experience gained in already installed plants will be outlined. Research experiments results on the use of various forms of wood and other biomass fuels, such as wood chips, pellets, peach pits, nut shells and kernels and refuse-derived fuels, will be described for small and medium sized fire-tube boilers, and for larger water-tube boilers for co-generation. (Refs. 4).

  3. Storage opportunities in Arizona bedded evaporites

    SciTech Connect (OSTI)

    Neal, J.T.; Rauzi, S.L.

    1996-10-01

    Arizona is endowed with incredibly diverse natural beauty, and has also been blessed with at least seven discrete deposits of bedded salt. These deposits are dispersed around the state and cover some 2, 500 square miles; they currently contain 14 LPG storage caverns, with preliminary plans for more in the future. The areal extent and thickness of the deposits creates the opportunity for greatly expanded storage of LPG, natural gas, and compressed air energy storage (CAES). The location of salt deposits near Tucson and Phoenix may make CAES an attractive prospect in the future. The diversity of both locations and evaporate characteristics allows for much tailoring of individual operations to meet specific requirements.

  4. Fluidized bed pyrolysis to gases containing olefins

    SciTech Connect (OSTI)

    Kuester, J.L.

    1980-01-01

    Recent gasification data are presented for a system designed to produce liquid hydrocarbon fuel from various biomass feedstocks. The factors under investigation were feedstock type, fluidizing gas type, residence time, temperature and catalyst usage. The response was gas phase composition. A fluidized bed system was utilized with a separate regenerator-combustor. An olefin content as high as 39 mole % was achieved. Hydrogen/carbon monoxide ratios were easily manipulated via steam addition over a broad range with an autocatalytic effect apparent for most feedstocks.

  5. Growth and flowering of bedding plants grown in landscape bed amended with hydrophilic polymers 

    E-Print Network [OSTI]

    Boatright, Jennifer Lynn

    1994-01-01

    Field study one incorporated hydrophilic polymers into field plots of bedding plants including 25, 50, 75, or 1 00 lb/1 00oft2 . Data recorded during the growing season included flower number, visual rating, soil moisture and temperature, and plant...

  6. Perceived consequences and concerns in the diffusion of Internet2 at Texas A&M University 

    E-Print Network [OSTI]

    Mendoza Diaz, Noemi Veronica

    2009-05-15

    development and its relationship to universities. There were two theoretical models of change used, Diffusion of Innovations and Concerns-Based Adoption Model (CBAM). Specifically, “the consequences of change” was the focus in the Diffusion model, and “the...

  7. Geomechanical Analysis and Design Considerations for Thin-Bedded Salt Caverns

    SciTech Connect (OSTI)

    Michael S. Bruno

    2005-06-15

    The bedded salt formations located throughout the United States are layered and interspersed with non-salt materials such as anhydrite, shale, dolomite and limestone. The salt layers often contain significant impurities. GRI and DOE have initialized this research proposal in order to increase the gas storage capabilities by providing operators with improved geotechnical design and operating guidelines for thin bedded salt caverns. Terralog has summarized the geologic conditions, pressure conditions, and critical design factors that may lead to: (1) Fracture in heterogeneous materials; (2) Differential deformation and bedding plane slip; (3) Propagation of damage around single and multiple cavern; and (4) Improved design recommendations for single and multiple cavern configurations in various bedded salt environments. The existing caverns within both the Permian Basin Complex and the Michigan and Appalachian Basins are normally found between 300 m to 1,000 m (1,000 ft to 3,300 ft) depth depending on local geology and salt dissolution depth. Currently, active cavern operations are found in the Midland and Anadarko Basins within the Permian Basin Complex and in the Appalachian and Michigan Basins. The Palo Duro and Delaware Basins within the Permian Basin Complex also offer salt cavern development potential. Terralog developed a number of numerical models for caverns located in thin bedded salt. A modified creep viscoplastic model has been developed and implemented in Flac3D to simulate the response of salt at the Permian, Michigan and Appalachian Basins. The formulation of the viscoplastic salt model, which is based on an empirical creep law developed for Waste Isolation Pilot Plant (WIPP) Program, is combined with the Drucker-Prager model to include the formation of damage and failure. The Permian salt lab test data provided by Pfeifle et al. 1983, are used to validate the assumptions made in the material model development. For the actual cavern simulations two baseline models are developed for single and multiple caverns, respectively. Different parameters that affect damage propagation and deformation of salt cavern, such as cavern pressure, operating conditions, cavern height/diameter ratio, overburden stiffness and roof thickness are analyzed and the respective results summarized. For multiple horizontal caverns numerical models are developed to determine the cavern interaction and the minimum safe center to center distance. A step by step methodology for operators to assess critical cavern design parameters for thin bedded salt formations is also presented.

  8. Deep Bed Adsorption Testing using Silver-Functionalized Aerogel...

    Office of Scientific and Technical Information (OSTI)

    Bed Adsorption Testing using Silver-Functionalized Aerogel Nick Soelberg; Tony Watson 12 MGMT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES aerogel; iodine...

  9. CERTS Microgrid Laboratory Test Bed - PIER Final Project Report

    E-Print Network [OSTI]

    Eto, Joseph H.

    2008-01-01

    Interest Energy Research CERTS Microgrid Test Bed Project 30a research project for the New York State Energy Researcha research project for the New York State Energy Research

  10. Geomechanical Analysis and Design Considerations for Thin-Bedded...

    Office of Scientific and Technical Information (OSTI)

    Geomechanical Analysis and Design Considerations for Thin-Bedded Salt Caverns Citation Details In-Document Search Title: Geomechanical Analysis and Design Considerations for...

  11. Deep Bed Adsorption Testing using Silver-Functionalized Aerogel...

    Office of Scientific and Technical Information (OSTI)

    In-Document Search Title: Deep Bed Adsorption Testing using Silver-Functionalized Aerogel Nuclear fission results in the production of fission products and activation products,...

  12. Fluidized Bed Technology - An R&D Success Story | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    line. The Nucla fluidized bed power plant in Colorado was operated in DOE's Clean Coal Technology Program. The technology progressed into larger scale utility applications...

  13. National SCADA Test Bed - Enhancing control systems security...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    of the systems still in use today were designed to operate in closed, proprietary networks. National SCADA Test Bed - Enhancing control systems security in the energy sector...

  14. Simulation of NOx emission in circulating fluidized beds burning low-grade fuels

    SciTech Connect (OSTI)

    Afsin Gungor

    2009-05-15

    Nitrogen oxides are a major environmental pollutant resulting from combustion. This paper presents a modeling study of pollutant NOx emission resulting from low-grade fuel combustion in a circulating fluidized bed. The simulation model accounts for the axial and radial distribution of NOx emission in a circulating fluidized bed (CFB). The model results are compared with and validated against experimental data both for small-size and industrial-size CFBs that use different types of low-grade fuels given in the literature. The present study proves that CFB combustion demonstrated by both experimental data and model predictions produces low and acceptable levels of NOx emissions resulting from the combustion of low-grade fuels. Developed model can also investigate the effects of different operational parameters on overall NOx emission. As a result of this investigation, both experimental data and model predictions show that NOx emission increases with the bed temperature but decreases with excess air if other parameters are kept unchanged. 37 refs., 5 figs., 5 tabs.

  15. Costs and Consequences of Flooding Camilo Sarmiento, Ph.D.

    E-Print Network [OSTI]

    Costs and Consequences of Flooding Camilo Sarmiento, Ph.D. Senior Economist Fannie Mae #12 the impact that the NFIP has had on the flooding costs and the distribution of these costs among payers the NFIP loss database, the model examines losses in known flood events, infers total losses by cost

  16. Fluidized bed combustor and coal gun-tube assembly therefor

    DOE Patents [OSTI]

    Hosek, William S. (Mt. Tabor, NJ); Garruto, Edward J. (Wayne, NJ)

    1984-01-01

    A coal supply gun assembly for a fluidized bed combustor which includes heat exchange elements extending above the bed's distributor plate assembly and in which the gun's nozzles are disposed relative to the heat exchange elements to only discharge granular coal material between adjacent heat exchange elements and in a path which is substantially equidistant from adjacent heat exchange elements.

  17. Influence of partial wetting on trickle-bed reactor performance 

    E-Print Network [OSTI]

    Ruecker, Craig Michael

    1985-01-01

    , hydrodenitrogenation, hydrogenation. and hydrocracking of heavy oil residuals. Trickle-bed reactors are also being used for treatment of waste water. A trickle-bed reactor is a. three-phase reactor in which gas and liquid phases flow cocurrently downward over a...

  18. NNSA Holds Radiation Emergency Consequence Management Training...

    National Nuclear Security Administration (NNSA)

    Radiation Emergency Consequence Management Training in Israel | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile...

  19. An Analysis of the Use of Fluidized-Bed Heat Exchangers for Heat Recovery 

    E-Print Network [OSTI]

    Vogel, G. J.; Grogan, P. J.

    1980-01-01

    The principles of fluidized-bed operation and the factors affecting the performance of a fluidized-bed waste heat boiler (FBWHB) are discussed in detail. Factors included in the discussion are bed temperature and pressure, heat transfer coefficient...

  20. Synthetic aggregate compositions derived from spent bed materials from fluidized bed combustion and fly ash

    DOE Patents [OSTI]

    Boyle, Michael J. (Aston, PA)

    1994-01-01

    Cementitious compositions useful as lightweight aggregates are formed from a blend of spent bed material from fluidized bed combustion and fly ash. The proportions of the blend are chosen so that ensuing reactions eliminate undesirable constituents. The blend is then mixed with water and formed into a shaped article. The shaped article is preferably either a pellet or a "brick" shape that is later crushed. The shaped articles are cured at ambient temperature while saturated with water. It has been found that if used sufficiently, the resulting aggregate will exhibit minimal dimensional change over time. The aggregate can be certified by also forming standardized test shapes, e.g., cylinders while forming the shaped articles and measuring the properties of the test shapes using standardized techniques including X-ray diffraction.

  1. Method for enhancing the desulfurization of hot coal gas in a fluid-bed coal gasifier

    DOE Patents [OSTI]

    Grindley, Thomas (Morgantown, WV)

    1989-01-01

    A process and apparatus for providing additional desulfurization of the hot gas produced in a fluid-bed coal gasifier, within the gasifier. A fluid-bed of iron oxide is located inside the gasifier above the gasification bed in a fluid-bed coal gasifier in which in-bed desulfurization by lime/limestone takes place. The product gases leave the gasification bed typically at 1600.degree. to 1800.degree. F. and are partially quenched with water to 1000.degree. to 1200.degree. F. before entering the iron oxide bed. The iron oxide bed provides additional desulfurization beyond that provided by the lime/limestone.

  2. Numerical and experimental studies of IFE target layering in a cryogenic fluidized bed

    E-Print Network [OSTI]

    Boehm, Kurt Julian

    2009-01-01

    most gas-solid fluidized beds show a bubbling or chuggingfluidized state which is governed by bubbling behavior, the prediction of the bed

  3. Effect of Bed Sand Content on the Turbulent Flows Associated with Clusters on an

    E-Print Network [OSTI]

    Curran, Joanna C.

    Surface Joanna Crowe Curran, A.M.ASCE1 ; and Lu Tan2 Abstract: As a gravel bed river armors, a bed surface

  4. General Logic-Systems and Consequence Operators

    E-Print Network [OSTI]

    Robert A. Herrmann

    2006-06-03

    In this paper, general logic-systems are investigated. It is shown that there are infinitely many finite consequence operators defined on a fixed language L that cannot be generated from a finite logic-system. It is shown that a set map is a finite consequence operator iff it is defined by a general logic-system.

  5. Neural Network Based Montioring and Control of Fluidized Bed.

    SciTech Connect (OSTI)

    Bodruzzaman, M.; Essawy, M.A.

    1996-04-01

    The goal of this project was to develop chaos analysis and neural network-based modeling techniques and apply them to the pressure-drop data obtained from the Fluid Bed Combustion (FBC) system (a small scale prototype model) located at the Federal Energy Technology Center (FETC)-Morgantown. The second goal was to develop neural network-based chaos control techniques and provide a suggestive prototype for possible real-time application to the FBC system. The experimental pressure data were collected from a cold FBC experimental set-up at the Morgantown Center. We have performed several analysis on these data in order to unveil their dynamical and chaotic characteristics. The phase-space attractors were constructed from the one dimensional time series data, using the time-delay embedding method, for both normal and abnormal conditions. Several identifying parameters were also computed from these attractors such as the correlation dimension, the Kolmogorov entropy, and the Lyapunov exponents. These chaotic attractor parameters can be used to discriminate between the normal and abnormal operating conditions of the FBC system. It was found that, the abnormal data has higher correlation dimension, larger Kolmogorov entropy and larger positive Lyapunov exponents as compared to the normal data. Chaotic system control using neural network based techniques were also investigated and compared to conventional chaotic system control techniques. Both types of chaotic system control techniques were applied to some typical chaotic systems such as the logistic, the Henon, and the Lorenz systems. A prototype model for real-time implementation of these techniques has been suggested to control the FBC system. These models can be implemented for real-time control in a next phase of the project after obtaining further measurements from the experimental model. After testing the control algorithms developed for the FBC model, the next step is to implement them on hardware and link them to the experimental system. In this report, the hardware implementation issues of the control algorithms are also discussed.

  6. Implicit Ethnic Group Attitude and Stereotype Development: Causes and Consequences

    E-Print Network [OSTI]

    Gillen-O'Neel, Cari

    2014-01-01

    and Stereotype Development: Causes and Consequences Aand Stereotype Development: Causes and Consequences by Cariand stereotype development: causes and consequences M.A. in

  7. Molten thermite teeming into an iron oxide particle bed

    SciTech Connect (OSTI)

    Tarbell, W.W.; Blose, R.E.; Arellano, F.E.

    1984-03-01

    The two particle bed tests employed 10-kg thermite melts (2700/sup 0/K) teemed into a bed of iron oxide particles. Objective was to investigate bed penetration, particle flotation and fracture, and heat flux partitioning. The results show that the hydraulic forces exerted by the melt did not immediately displace the bed. Bed penetration was by melting and absorbing of the particles with the major portion of the displaced iron oxide terminating in the alumina phase of the melt. The movement of the penetration front suggests the movement to be a series of melt/freeze/remelt processes. The large grain structure of the iron phase indicates that the cooling was slow and continuous. A coherent 1-cm-thick layer of iron oxide in contact with the melt was created by sintering of the particles. The particle size of the unaffected portions of the bed showed very little fracturing due to thermal stress and slightly over 7% particle growth due to sintering. The calculated heat flux values to the surrounding crucible structure suggest that the bed is effective in delaying and reducing the magnitude of the peak heat flux values.

  8. Observational consequencies of baryonic gaseous dark matter

    E-Print Network [OSTI]

    Shchekinov, Yu A

    1998-01-01

    Possible observational consequencies of dark matter in the Galaxy in the form of dense molecular gas clouds -- clumpuscules of masses $M_c\\sim 10^{-3}~\\msun$ and radii $R_c\\sim 3\\times 10^{13}$ cm -- are considered. Recent models of the extreme scattering events -- refraction of radio-waves from quasars in dense plasma clumps in the Galactic halo -- definitely show on such clouds as possible dark matter candidate. We arugue that collisions of such clumpuscules are quite frequent: around $1-10~\\msun$ a year can be ejected in the intestellar medium due to collisions. Optical continuum and 21 cm emissions from post-collisional gas are found to be observable. We show that clumpuscules can form around O stars HII regions of sizes $R\\sim 30$ pc and emission measure $EM\\simeq 20$ cm$^{-6}$ pc, and can also be observable in $H_\\alpha$ emission. Evaporation of clumpuscules by external ionising radiation can be a substantial mass source. From requirement that the total mass input on the Hubble time cannot exceed the lu...

  9. Observational consequences of baryonic gaseous dark matter

    E-Print Network [OSTI]

    Yu. A. Shchekinov

    1998-12-03

    Possible observational consequences of dark matter in the Galaxy in the form of dense molecular gas clouds - clumpuscules of masses $M_c\\sim 10^{-3} \\msun$ and radii $R_c\\sim 3\\times 10^{13}$ cm - are considered. Recent models of the extreme scattering events - refraction of radio-waves from quasars in dense plasma clumps in the Galactic halo - definitely show on such clouds as possible dark matter candidate. We argue that collisions of such clumpuscules are quite frequent: around $1-10 \\msun$ a year can be ejected in the interstellar medium due to collisions. Optical continuum and 21 cm emissions from post-collisional gas are found to be observable. We show that clumpuscules can form around O stars HII regions of sizes $R\\sim 30$ pc and emission measure $EM\\simeq 20 cm^{-6}$ pc, and can also be observable in $H_\\alpha$ emission. Evaporation of clumpuscules by external ionizing radiation can be a substantial mass source. From requirement that the total mass input on the Hubble time cannot exceed the luminous mass in the Galaxy, typical radius of clouds is constrained as $R_c energy of the gas ejected by such clouds can be an efficient energy source for the Galactic halo.

  10. Conventional regression models Unlabelled units

    E-Print Network [OSTI]

    McCullagh, Peter

    Conventional regression models Unlabelled units Consequences Sampling bias in logistic models Peter effects #12;Conventional regression models Unlabelled units Consequences Outline 1 Conventional regression models Gaussian models Binary regression model Properties of conventional models 2 Unlabelled units Point

  11. Pebble-bed pebble motion: Simulation and Applications

    SciTech Connect (OSTI)

    Joshua J. Cogliati; Abderrafi M. Ougouag

    2011-11-01

    Pebble bed reactors (PBR) have moving graphite fuel pebbles. This unique feature provides advantages, but also means that simulation of the reactor requires understanding the typical motion and location of the granular flow of pebbles. This report presents a method for simulation of motion of the pebbles in a PBR. A new mechanical motion simulator, PEBBLES, efficiently simulates the key elements of motion of the pebbles in a PBR. This model simulates gravitational force and contact forces including kinetic and true static friction. It's used for a variety of tasks including simulation of the effect of earthquakes on a PBR, calculation of packing fractions, Dancoff factors, pebble wear and the pebble force on the walls. The simulator includes a new differential static friction model for the varied geometries of PBRs. A new static friction benchmark was devised via analytically solving the mechanics equations to determine the minimum pebble-to-pebble friction and pebble-to-surface friction for a five pebble pyramid. This pyramid check as well as a comparison to the Janssen formula was used to test the new static friction equations. Because larger pebble bed simulations involve hundreds of thousands of pebbles and long periods of time, the PEBBLES code has been parallelized. PEBBLES runs on shared memory architectures and distributed memory architectures. For the shared memory architecture, the code uses a new O(n) lock-less parallel collision detection algorithm to determine which pebbles are likely to be in contact. The new collision detection algorithm improves on the traditional non-parallel O(n log(n)) collision detection algorithm. These features combine to form a fast parallel pebble motion simulation. The PEBBLES code provides new capabilities for understanding and optimizing PBRs. The PEBBLES code has provided the pebble motion data required to calculate the motion of pebbles during a simulated earthquake. The PEBBLES code provides the ability to determine the contact forces and the lengths of motion in contact. This information combined with the proper wear coefficients can be used to determine the dust production from mechanical wear. These new capabilities enhance the understanding of PBRs, and the capabilities of the code will allow future improvements in understanding.

  12. ADVANCED SORBENT DEVELOPMENT PROGRAM; DEVELOPMENT OF SORBENTS FOR MOVING-BED AND FLUIDIZED-BED APPLICATIONS

    SciTech Connect (OSTI)

    R.E. AYALA; V.S. VENKATARAMANI

    1998-09-30

    The integrated gasification combined cycle (IGCC) power system using high-temperature coal gas cleanup is one of the most promising advanced technologies for the production of electric power from coal in an environmentally acceptable manner. Unlike conventional low-temperature cleanup systems that require costly heat exchangers, high-temperature coal gas cleanup systems can be operated near 482-538 °C (900-1000 °F) or higher, conditions that are a closer match with the gasifier and turbine components in the IGCC system, thus resulting is a more efficient overall system. GE is developing a moving-bed, high-temperature desulfurization system for the IGCC power cycle in which zinc-based regenerable sorbents are currently being used as desulfurization sorbents. Zinc titanate and other proprietary zinc-based oxides are being considered as sorbents for use in the Clean Coal Technology Demonstration Program at Tampa Electric Co.?s (TECo) Polk Power Station. Under cold startup conditions at TECo, desulfurization and regeneration may be carried out at temperatures as low as 343 °C (650 °F), hence a versatile sorbent is desirable to perform over this wide temperature range. A key to success in the development of high-temperature desulfurization systems is the matching of sorbent properties for the selected process operating conditions, namely, sustainable desulfurization kinetics, high sulfur capacity, and mechanical durability over multiple cycles. Additionally, the sulfur species produced during regeneration of the sorbent must be in a form compatible with sulfur recovery systems, such as sulfuric acid or elemental sulfur processes. The overall objective of this program is to develop regenerable sorbents for hydrogen sulfide removal from coal-derived fuel gases in the temperature range 343-538 °C (650-1000 °F). Two categories of reactor configurations are being considered: moving-bed reactors and fluidized-bed (bubbling and circulating) reactors. In addition, a cost assessment and a market plan for large-scale fabrication of sorbents were developed. As an optional task, long-term bench-scale tests of the best moving-bed sorbents were conducted. Starting from thermodynamic calculations, several metal oxides were identified for potential use as hot gas cleanup sorbents using constructed phase stability diagrams and laboratory screening of various mixed-metal oxide formulations. Modified zinc titanates and other proprietary metal oxide formulations were evaluated at the bench scale and many of them found to be acceptable for operation in the target desulfurization temperature range of 370 °C (700 °F) to 538 °C (1000 °F) and regeneration tempera-tures up to 760 °C (1400 °F). Further work is still needed to reduce the batch-to-batch repeatability in the fabrication of modified zinc titanates for larger scale applications. The information presented in this Volume 1 report contains the results of moving-bed sorbent develop-ment at General Electric?s Corporate Research and Development (GE-CRD). A separate Volume 2 report contains the results of the subcontract on fluidized-bed sorbent development at the Institute of Gas Technology (IGT).

  13. ADVANCED SORBENT DEVELOPMENT PROGRAM DEVELOPMENT OF SORBENTS FOR MOVING-BED AND FLUIDIZED-BED APPLICATIONS

    SciTech Connect (OSTI)

    R.E Ayala; V.S. Venkataramani; Javad Abbasian; Rachid B. Slimane; Brett E. Williams; Minoo K. Zarnegar; James R. Wangerow; Andy H. Hill

    2000-03-31

    The integrated gasification combined cycle (IGCC) power system using high-temperature coal gas cleanup is one of the most promising advanced technologies for the production of electric power from coal in an environmentally acceptable manner. Unlike conventional low-temperature cleanup systems that require costly heat exchangers, high-temperature coal gas cleanup systems can be operated near 482-538 C (900-1000 F) or higher, conditions that are a closer match with the gasifier and turbine components in the IGCC system, thus resulting is a more efficient overall system. GE is developing a moving-bed, high-temperature desulfurization system for the IGCC power cycle in which zinc-based regenerable sorbents are currently being used as desulfurization sorbents. Zinc titanate and other proprietary zinc-based oxides are being considered as sorbents for use in the Clean Coal Technology Demonstration Program at Tampa Electric Co.'s (TECo) Polk Power Station. Under cold startup conditions at TECo, desulfurization and regeneration may be carried out at temperatures as low as 343 C (650 F), hence a versatile sorbent is desirable to perform over this wide temperature range. A key to success in the development of high-temperature desulfurization systems is the matching of sorbent properties for the selected process operating conditions, namely, sustainable desulfurization kinetics, high sulfur capacity, and mechanical durability over multiple cycles. Additionally, the sulfur species produced during regeneration of the sorbent must be in a form compatible with sulfur recovery systems, such as sulfuric acid or elemental sulfur processes. The overall objective of this program is to develop regenerable sorbents for hydrogen sulfide removal from coal-derived fuel gases in the temperature range 343-538 C (650-1000 F). Two categories of reactor configurations are being considered: moving-bed reactors and fluidized-bed (bubbling and circulating) reactors. In addition, a cost assessment and a market plan for large-scale fabrication of sorbents were developed. As an optional task, long-term bench-scale tests of the best moving-bed sorbents were conducted. Starting from thermodynamic calculations, several metal oxides were identified for potential use as hot gas cleanup sorbents using constructed phase stability diagrams and laboratory screening of various mixed-metal oxide formulations. Modified zinc titanates and other proprietary metal oxide formulations were evaluated at the bench scale and many of them found to be acceptable for operation in the target desulfurization temperature range of 370 C (700 F) to 538 C (1000 F) and regeneration temperatures up to 760 C (1400 F). Further work is still needed to reduce the batch-to-batch repeatability in the fabrication of modified zinc titanates for larger scale applications. The information presented in this Volume 1 report contains the results of moving-bed sorbent development at General Electric's Corporate Research and Development (GE-CRD). A separate Volume 2 report contains the results of the subcontract on fluidized-bed sorbent development at the Institute of Gas Technology (IGT).

  14. Fluidized bed pyrolysis of terrestrial biomass feedstocks

    SciTech Connect (OSTI)

    Besler, S.; Agblevor, F.A.; Davis, M.F. [National Renewable Energy Lab., Golden, CO (United States)] [and others

    1994-12-31

    Hybrid poplar, switchgrass, and corn stover were pyrolyzed in a bench scale fluidized-bed reactor to examine the influence of storage time on thermochemical converting of these materials. The influence of storage on the thermochemical conversion of the biomass feedstocks was assessed based on pyrolysis product yields and chemical and instrumental analyses of the pyrolysis products. Although char and gas yields from corn stover feedstock were influenced by storage time, hybrid poplar and switchgrass were not significantly affected. Liquid, char, and gas yields were feedstock dependent. Total liquid yields (organic+water) varied from 58%-73% depending on the feedstock. Char yields varied from 14%-19% while gas yields ranged from 11%-15%. The chemical composition of the pyrolysis oils from hybrid polar feedstock was slightly changed by storage, however, corn stover and switchgrass feedstock showed no significant changes. Additionally, stored corn stover and hybrid poplar pyrolysis oils showed a significant decrease in their higher heating values compared to the fresh material.

  15. Apparatus for fixed bed coal gasification

    DOE Patents [OSTI]

    Sadowski, Richard S. (Greenville, SC)

    1992-01-01

    An apparatus for fixed-bed coal gasification is described in which coal such as caking coal is continuously pyrolyzed with clump formation inhibited, by combining the coal with a combustible gas and an oxidant, and then continually feeding the pyrolyzed coal under pressure and elevated temperature into the gasification region of a pressure vessel. The materials in the pressure vessel are allowed to react with the gasifying agents in order to allow the carbon contents of the pyrolyzed coal to be completely oxidized. The combustion of gas produced from the combination of coal pyrolysis and gasification involves combining a combustible gas coal and an oxidant in a pyrolysis chamber and heating the components to a temperature of at least 1600.degree. F. The products of coal pyrolysis are dispersed from the pyrolyzer directly into the high temperature gasification region of a pressure vessel. Steam and air needed for gasification are introduced in the pressure vessel and the materials exiting the pyrolyzer flow down through the pressure vessel by gravity with sufficient residence time to allow any carbon to form carbon monoxide. Gas produced from these reactions are then released from the pressure vessel and ash is disposed of.

  16. Cross-flow versus counter-current flow packed-bed scrubbers: a mathematical analysis

    SciTech Connect (OSTI)

    Fthenakis, V.M.

    1996-02-01

    Little is known about the mass transfer properties of packing media exposed to a crossflow of gas and liquid, whereas there is abundant information related to counter-current scrubbers. This paper presents a theoretical analysis of mass transfer and hydrodynamics in cross- flow packed bed scrubbers and compares those with information available for counter current towers, so that the first can be evaluated and/or designed based on data derived for the second. Mathematical models of mass transfer in cross-flow and counter- current packed bed scrubbers are presented. From those, one can predict the removal effectiveness of a crossflow scrubber from the number of transfer units (NTU) calculated for a similar counterflow operation; alternatively, when the removal effectiveness in counterflow is known, one can predict the corresponding NTU in crossflow.

  17. Supporting Calculations For Submerged Bed Scrubber Condensate Disposal Preconceptual Study

    SciTech Connect (OSTI)

    Pajunen, A. J.; Tedeschi, A. R.

    2012-09-18

    This document provides supporting calculations for the preparation of the Submerged Bed Scrubber Condensate Disposal Preconceptual Study report The supporting calculations include equipment sizing, Hazard Category determination, and LAW Melter Decontamination Factor Adjustments.

  18. PEBBLE-BED NUCLEAR REACTOR SYSTEM PHYSICS AND FUEL UTILIZATION 

    E-Print Network [OSTI]

    Kelly, Ryan 1989-

    2011-04-20

    The Generation IV Pebble Bed Modular Reactor (PMBR) design may be used for electricity production, co-generation applications (industrial heat, hydrogen production, desalination, etc.), and could potentially eliminate some high level nuclear wastes...

  19. Gas phase hydrodynamics inside a circulating fluidized bed

    E-Print Network [OSTI]

    Moran, James C. (James Christopher)

    2001-01-01

    Circulating Fluidized Beds (CFB's) offer many advantages over traditional pulverized coal burners in the power generation industry. They operate at lower temperatures, have better environmental emissions and better fuel ...

  20. BEDDED BARITE IN THE GEOLOGIC RECORD PAUL W. JEWELL*

    E-Print Network [OSTI]

    Johnson, Cari

    in understnnditig bedded barite genesis. The low solt~bilityof barite relntivc to other na(ura1 salts has Iicllied make it econonlically usefill, particularly ill the manufacture of drilling nluds for the oil and gas

  1. CONTROLS ON FOOD WEBS IN GRAVEL-BEDDED RIVERS: THE

    E-Print Network [OSTI]

    Power, Mary Eleanor

    Gravel-BedRivers V 405 #12;and more rapidly than comparable physical features in other (terrestrial of energy or materials (nutrients, contaminants) through food webs. These pathways of trophic transfer

  2. Bathymetric evolution of sand bed forms under partially standing waves

    E-Print Network [OSTI]

    Landry, Blake Jude

    2004-01-01

    Experiments were conducted in a large wave flume where the interaction between water waves and a movable sand bed were investigated. Monochromatic and poly- chromatic waves of specified amplitudes and period were generated ...

  3. Computational Analysis of Fluid Flow in Pebble Bed Modular Reactor 

    E-Print Network [OSTI]

    Gandhir, Akshay

    2012-10-19

    High Temperature Gas-cooled Reactor (HTGR) is a Generation IV reactor under consideration by Department of Energy and in the nuclear industry. There are two categories of HTGRs, namely, Pebble Bed Modular Reactor (PBMR) and Prismatic reactor. Pebble...

  4. Shielded fluid stream injector for particle bed reactor

    DOE Patents [OSTI]

    Notestein, John E. (Morgantown, WV)

    1993-01-01

    A shielded fluid-stream injector assembly is provided for particle bed reactors. The assembly includes a perforated pipe injector disposed across the particle bed region of the reactor and an inverted V-shaped shield placed over the pipe, overlapping it to prevent descending particles from coming into direct contact with the pipe. The pipe and shield are fixedly secured at one end to the reactor wall and slidably secured at the other end to compensate for thermal expansion. An axially extending housing aligned with the pipe and outside the reactor and an in-line reamer are provided for removing deposits from the inside of the pipe. The assembly enables fluid streams to be injected and distributed uniformly into the particle bed with minimized clogging of injector ports. The same design may also be used for extraction of fluid streams from particle bed reactors.

  5. NONLINEARITY AND COMPLEXITY IN GRAVEL BED DYNAMICS Arvind Singh

    E-Print Network [OSTI]

    NONLINEARITY AND COMPLEXITY IN GRAVEL BED DYNAMICS By Arvind Singh Stefano Lanzoni and Efi Foufoula Singh1 , Stefano Lanzoni2 , and Efi Foufoula-Georgiou1 1 St. Anthony Falls Laboratory and National

  6. ANALYSIS OF METHANE PRODUCING COMMUNITIES WITHIN UNDERGROUND COAL BEDS

    E-Print Network [OSTI]

    Maxwell, Bruce D.

    ANALYSIS OF METHANE PRODUCING COMMUNITIES WITHIN UNDERGROUND COAL BEDS by Elliott Paul Barnhart.........................................................................................8 Coal and Metabolite Enrichment Studies ..................................................................................14 Ability of the Consortium to Produce Methane from Coal and Metabolites ................16

  7. Quantifying the impact of decay in bed-net efficacy on malaria transmission

    SciTech Connect (OSTI)

    Ngonghala, Calistus N.; Del Valle, Sara Y.; Zhao, Ruijun; Mohammed-Awel, Jemal

    2014-08-23

    Insecticide-treated nets (ITNs) are at the forefront of malaria control programs and even though the percentage of households in sub-Saharan Africa that owned nets increased from 3% in 2000 to 53% in 2012, many children continue to die from malaria. The potential impact of ITNs on reducing malaria transmission is limited due to inconsistent or improper use, as well as physical decay in effectiveness. Most mathematical models for malaria transmission have assumed a fixed effectiveness rate for bed-nets, which can overestimate the impact of nets on malaria control. We develop a model for malaria spread that captures the decrease in ITN effectiveness due to physical and chemical decay, as well as human behavior as a function of time. We perform uncertainty and sensitivity analyses to identify and rank parameters that play a critical role in malaria transmission. These analyses show that the basic reproduction number R0, and the infectious human population are most sensitive to bed-net coverage and the biting rate of mosquitoes. Our results show the existence of a backward bifurcation for the case in which ITN efficacy is constant over time, which occurs for some range of parameters and is characterized by high malaria mortality in humans. This result implies that bringing R0 to less than one is not enough for malaria elimination but rather additional efforts will be necessary to control the disease. For the case in which ITN efficacy decays over time, we determine coverage levels required to control malaria for different ITN efficacies and demonstrate that ITNs with longer useful lifespans perform better in malaria control. We conclude that malaria control programs should focus on increasing bed-net coverage, which can be achieved by enhancing malaria education and increasing bed-net distribution in malaria endemic regions.

  8. Quantifying the impact of decay in bed-net efficacy on malaria transmission

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ngonghala, Calistus N.; Del Valle, Sara Y.; Zhao, Ruijun; Mohammed-Awel, Jemal

    2014-08-23

    Insecticide-treated nets (ITNs) are at the forefront of malaria control programs and even though the percentage of households in sub-Saharan Africa that owned nets increased from 3% in 2000 to 53% in 2012, many children continue to die from malaria. The potential impact of ITNs on reducing malaria transmission is limited due to inconsistent or improper use, as well as physical decay in effectiveness. Most mathematical models for malaria transmission have assumed a fixed effectiveness rate for bed-nets, which can overestimate the impact of nets on malaria control. We develop a model for malaria spread that captures the decrease inmore »ITN effectiveness due to physical and chemical decay, as well as human behavior as a function of time. We perform uncertainty and sensitivity analyses to identify and rank parameters that play a critical role in malaria transmission. These analyses show that the basic reproduction number R0, and the infectious human population are most sensitive to bed-net coverage and the biting rate of mosquitoes. Our results show the existence of a backward bifurcation for the case in which ITN efficacy is constant over time, which occurs for some range of parameters and is characterized by high malaria mortality in humans. This result implies that bringing R0 to less than one is not enough for malaria elimination but rather additional efforts will be necessary to control the disease. For the case in which ITN efficacy decays over time, we determine coverage levels required to control malaria for different ITN efficacies and demonstrate that ITNs with longer useful lifespans perform better in malaria control. We conclude that malaria control programs should focus on increasing bed-net coverage, which can be achieved by enhancing malaria education and increasing bed-net distribution in malaria endemic regions.« less

  9. Stochastic Consequence Analysis for Waste Leaks

    SciTech Connect (OSTI)

    HEY, B.E.

    2000-05-31

    This analysis evaluates the radiological consequences of potential Hanford Tank Farm waste transfer leaks. These include ex-tank leaks into structures, underneath the soil, and exposed to the atmosphere. It also includes potential misroutes, tank overflow

  10. Performance characterization of a packed bed electro-filter 

    E-Print Network [OSTI]

    Narayanan, Ajay

    1990-01-01

    PERFORMANCE CHARACTERIZATION OF A PACKED BED ELECTRO-FILTER A Thesis by A JAY NARAYANAN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... December 1990 Major Subject: Safety Engineering PERFORMANCE CHARACTERIZATION OF A PACKED BED ELECTRO-FILTER A Thesis by AJAY NARAYANAN Approved as to style and content by: John P. Wagn (Ch ' of the Com ittee) Aydin Akgerman (Member) Ri ard B...

  11. 1Practical Guide to Bed Bug Prevention --E-261-W Household & Structural

    E-Print Network [OSTI]

    Pittendrigh, Barry

    of Entomology Bed bug bite. (Photo credit: Tom Myers) *Multipule-family housing units are often thought with a known or suspected bed bug problem. Immediate help is critical to avoid spreading bed bugs. (Photo credit: Tom Myers) tions or asthma, especially in children. Bed bugs must feed several times

  12. Erosion of a granular bed driven by laminar fluid flow

    E-Print Network [OSTI]

    A. E. Lobkovsky; A. V. Orpe; R. Molloy; A. Kudrolli; D. H. Rothman

    2008-05-01

    Motivated by examples of erosive incision of channels in sand, we investigate the motion of individual grains in a granular bed driven by a laminar fluid to give us new insights into the relationship between hydrodynamic stress and surface granular flow. A closed cell of rectangular cross-section is partially filled with glass beads and a constant fluid flux $Q$ flows through the cell. The refractive indices of the fluid and the glass beads are matched and the cell is illuminated with a laser sheet, allowing us to image individual beads. The bed erodes to a rest height $h_r$ which depends on $Q$. The Shields threshold criterion assumes that the non-dimensional ratio $\\theta$ of the viscous stress on the bed to the hydrostatic pressure difference across a grain is sufficient to predict the granular flux. Furthermore, the Shields criterion states that the granular flux is non-zero only for $\\theta >\\theta_c$. We find that the Shields criterion describes the observed relationship $h_r \\propto Q^{1/2}$ when the bed height is offset by approximately half a grain diameter. Introducing this offset in the estimation of $\\theta$ yields a collapse of the measured Einstein number $q^*$ to a power-law function of $\\theta - \\theta_c$ with exponent $1.75 \\pm 0.25$. The dynamics of the bed height relaxation are well described by the power law relationship between the granular flux and the bed stress.

  13. Development and applications of clean coal fluidized bed technology

    SciTech Connect (OSTI)

    Eskin, N.; Hepbasli, A. [Ege University, Izmir (Turkey). Faculty of Engineering

    2006-09-15

    Power generation in Europe and elsewhere relies heavily on coal and coal-based fuels as the source of energy. The reliance will increase in the future due to the decreasing stability of price and security of oil supply. In other words, the studies on fluidized bed combustion systems, which is one of the clean coal technologies, will maintain its importance. The main objective of the present study is to introduce the development and the applications of the fluidized bed technology (FBT) and to review the fluidized bed combustion studies conducted in Turkey. The industrial applications of the fluidized bed technology in the country date back to the 1980s. Since then, the number of the fluidized bed boilers has increased. The majority of the installations are in the textile sector. In Turkey, there is also a circulating fluidized bed thermal power plant with a capacity of 2 x 160 MW under construction at Can in Canakkale. It is expected that the FBT has had, or will have, a significant and increasing role in dictating the energy strategies for Turkey.

  14. Ash level meter for a fixed-bed coal gasifier

    DOE Patents [OSTI]

    Fasching, George E. (Morgantown, WV)

    1984-01-01

    An ash level meter for a fixed-bed coal gasifier is provided which utilizes the known ash level temperature profile to monitor the ash bed level. A bed stirrer which travels up and down through the extent of the bed ash level is modified by installing thermocouples to measure the bed temperature as the stirrer travels through the stirring cycle. The temperature measurement signals are transmitted to an electronic signal process system by an FM/FM telemetry system. The processing system uses the temperature signals together with an analog stirrer position signal, taken from a position transducer disposed to measure the stirrer position to compute the vertical location of the ash zone upper boundary. The circuit determines the fraction of each total stirrer cycle time the stirrer-derived bed temperature is below a selected set point, multiplies this fraction by the average stirrer signal level, multiplies this result by an appropriate constant and adds another constant such that a 1 to 5 volt signal from the processor corresponds to a 0 to 30 inch span of the ash upper boundary level. Three individual counters in the processor store clock counts that are representative of: (1) the time the stirrer temperature is below the set point (500.degree. F.), (2) the time duration of the corresponding stirrer travel cycle, and (3) the corresponding average stirrer vertical position. The inputs to all three counters are disconnected during any period that the stirrer is stopped, eliminating corruption of the measurement by stirrer stoppage.

  15. Benchmark Evaluation of HTR-PROTEUS Pebble Bed Experimental Program

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Bess, John D.; Montierth, Leland; Köberl, Oliver; Snoj, Luka

    2014-10-09

    Benchmark models were developed to evaluate 11 critical core configurations of the HTR-PROTEUS pebble bed experimental program. Various additional reactor physics measurements were performed as part of this program; currently only a total of 37 absorber rod worth measurements have been evaluated as acceptable benchmark experiments for Cores 4, 9, and 10. Dominant uncertainties in the experimental keff for all core configurations come from uncertainties in the ˛ł?U enrichment of the fuel, impurities in the moderator pebbles, and the density and impurity content of the radial reflector. Calculations of keff with MCNP5 and ENDF/B-VII.0 neutron nuclear data are greatermore »than the benchmark values but within 1% and also within the 3? uncertainty, except for Core 4, which is the only randomly packed pebble configuration. Repeated calculations of keff with MCNP6.1 and ENDF/B-VII.1 are lower than the benchmark values and within 1% (~3?) except for Cores 5 and 9, which calculate lower than the benchmark eigenvalues within 4?. The primary difference between the two nuclear data libraries is the adjustment of the absorption cross section of graphite. Simulations of the absorber rod worth measurements are within 3? of the benchmark experiment values. The complete benchmark evaluation details are available in the 2014 edition of the International Handbook of Evaluated Reactor Physics Benchmark Experiments.« less

  16. Benchmark Evaluation of HTR-PROTEUS Pebble Bed Experimental Program

    SciTech Connect (OSTI)

    Bess, John D.; Montierth, Leland; Köberl, Oliver; Snoj, Luka

    2014-10-09

    Benchmark models were developed to evaluate 11 critical core configurations of the HTR-PROTEUS pebble bed experimental program. Various additional reactor physics measurements were performed as part of this program; currently only a total of 37 absorber rod worth measurements have been evaluated as acceptable benchmark experiments for Cores 4, 9, and 10. Dominant uncertainties in the experimental keff for all core configurations come from uncertainties in the ˛ł?U enrichment of the fuel, impurities in the moderator pebbles, and the density and impurity content of the radial reflector. Calculations of keff with MCNP5 and ENDF/B-VII.0 neutron nuclear data are greater than the benchmark values but within 1% and also within the 3? uncertainty, except for Core 4, which is the only randomly packed pebble configuration. Repeated calculations of keff with MCNP6.1 and ENDF/B-VII.1 are lower than the benchmark values and within 1% (~3?) except for Cores 5 and 9, which calculate lower than the benchmark eigenvalues within 4?. The primary difference between the two nuclear data libraries is the adjustment of the absorption cross section of graphite. Simulations of the absorber rod worth measurements are within 3? of the benchmark experiment values. The complete benchmark evaluation details are available in the 2014 edition of the International Handbook of Evaluated Reactor Physics Benchmark Experiments.

  17. Method of burning sulfur-containing fuels in a fluidized bed boiler

    DOE Patents [OSTI]

    Jones, Brian C. (Windsor, CT)

    1982-01-01

    A method of burning a sulfur-containing fuel in a fluidized bed of sulfur oxide sorbent wherein the overall utilization of sulfur oxide sorbent is increased by comminuting the bed drain solids to a smaller average particle size, preferably on the order of 50 microns, and reinjecting the comminuted bed drain solids into the bed. In comminuting the bed drain solids, particles of spent sulfur sorbent contained therein are fractured thereby exposing unreacted sorbent surface. Upon reinjecting the comminuted bed drain solids into the bed, the newly-exposed unreacted sorbent surface is available for sulfur oxide sorption, thereby increasing overall sorbent utilization.

  18. Advanced Core Design And Fuel Management For Pebble-Bed Reactors

    SciTech Connect (OSTI)

    Hans D. Gougar; Abderrafi M. Ougouag; William K. Terry

    2004-10-01

    A method for designing and optimizing recirculating pebble-bed reactor cores is presented. At the heart of the method is a new reactor physics computer code, PEBBED, which accurately and efficiently computes the neutronic and material properties of the asymptotic (equilibrium) fuel cycle. This core state is shown to be unique for a given core geometry, power level, discharge burnup, and fuel circulation policy. Fuel circulation in the pebble-bed can be described in terms of a few well?defined parameters and expressed as a recirculation matrix. The implementation of a few heat?transfer relations suitable for high-temperature gas-cooled reactors allows for the rapid estimation of thermal properties critical for safe operation. Thus, modeling and design optimization of a given pebble-bed core can be performed quickly and efficiently via the manipulation of a limited number key parameters. Automation of the optimization process is achieved by manipulation of these parameters using a genetic algorithm. The end result is an economical, passively safe, proliferation-resistant nuclear power plant.

  19. Two stage, low temperature, catalyzed fluidized bed incineration with in situ neutralization for radioactive mixed wastes

    SciTech Connect (OSTI)

    Wade, J.F.; Williams, P.M.

    1995-05-17

    A two stage, low temperature, catalyzed fluidized bed incineration process is proving successful at incinerating hazardous wastes containing nuclear material. The process operates at 550{degrees}C and 650{degrees}C in its two stages. Acid gas neutralization takes place in situ using sodium carbonate as a sorbent in the first stage bed. The feed material to the incinerator is hazardous waste-as defined by the Resource Conservation and Recovery Act-mixed with radioactive materials. The radioactive materials are plutonium, uranium, and americium that are byproducts of nuclear weapons production. Despite its low temperature operation, this system successfully destroyed poly-chlorinated biphenyls at a 99.99992% destruction and removal efficiency. Radionuclides and volatile heavy metals leave the fluidized beds and enter the air pollution control system in minimal amounts. Recently collected modeling and experimental data show the process minimizes dioxin and furan production. The report also discusses air pollution, ash solidification, and other data collected from pilot- and demonstration-scale testing. The testing took place at Rocky Flats Environmental Technology Site, a US Department of Energy facility, in the 1970s, 1980s, and 1990s.

  20. Moving granular-bed filter development program topical report

    SciTech Connect (OSTI)

    Newby, R.A.; Dilmore, W.J.; Fellers, A.W.; Gasparovic, A.C.; Kittle, W.F.; Lippert, T.E.; Smeltzer, E.E.; Yang, W.C.

    1991-10-17

    The Westinghouse Science Technology Center has proposed a novel moving granular-bed filter concept, the Standleg Moving Granular-Bed Filter (S-MGBF) system, that overcomes the inherent deficiencies of the current state-of-the-art moving granular-bed filter technology. The S-MGBF system combines two unique features that make it highly effective for use in advanced coal-fueled power plants. First, the S-MGBF system applies pelletization technology to generate filter pellets from the power plant solid waste materials, and uses these pellets as a once-through'' filtering media to eliminate the need for costly, complex, and large filter media recycling equipment. This pelletizing step also generates a more environmentally acceptable solid waste product and provides the potential to incorporate gas-phase contaminant sorbents into the filtering media. Secondly, the S-MGBF system passes these pellets and the flyash laden power plant gas through a highly compact S-MGBF that uses cocurrent gas-pellet contacting in an arrangement that greatly simplifies and enhances the distribution of dirty gas to the moving bed and the disengagement of clean gas from the moving bed.

  1. Materials performance in fluidized-bed air heaters

    SciTech Connect (OSTI)

    Natesan, K.; Podolski, W.

    1991-12-01

    Development of cogeneration systems that involve combustion of coal in a fluidized bed and use of air heaters to generate hot air for turbine systems has been in progress for a number of years. The US Department of Energy (DOE) sponsored the Atmospheric Fluidized-Bed Cogeneration Air Heater Experiment (ACAHE) to assess the performance of various heat exchanger materials and establish confidence in the resultant designs of fluidized-bed-combustion air heater systems. Westinghouse Electric Corporation, in association with Babcock Wilcox, Foster Wheeler, and ABB/Combustion Engineering, prepared specifications and hardware for the ACAHE. Argonne National Laboratory, through a contract with the Rocketdyne Division of Rockwell International, conducted tests in the DOE 1.8 {times} 1.8 m atmospheric fluidized-bed combustion facility in El Segundo, California. This paper presents an assessment of the materials performance in fluidized bed environments and examines guidelines for materials selection on the basis of corrosion resistance in air and in combustion environments, mechanical properties, fabricability/thermal stability, and cost.

  2. Materials performance in fluidized-bed air heaters

    SciTech Connect (OSTI)

    Natesan, K.; Podolski, W.

    1991-12-01

    Development of cogeneration systems that involve combustion of coal in a fluidized bed and use of air heaters to generate hot air for turbine systems has been in progress for a number of years. The US Department of Energy (DOE) sponsored the Atmospheric Fluidized-Bed Cogeneration Air Heater Experiment (ACAHE) to assess the performance of various heat exchanger materials and establish confidence in the resultant designs of fluidized-bed-combustion air heater systems. Westinghouse Electric Corporation, in association with Babcock & Wilcox, Foster Wheeler, and ABB/Combustion Engineering, prepared specifications and hardware for the ACAHE. Argonne National Laboratory, through a contract with the Rocketdyne Division of Rockwell International, conducted tests in the DOE 1.8 {times} 1.8 m atmospheric fluidized-bed combustion facility in El Segundo, California. This paper presents an assessment of the materials performance in fluidized bed environments and examines guidelines for materials selection on the basis of corrosion resistance in air and in combustion environments, mechanical properties, fabricability/thermal stability, and cost.

  3. Waveinduced velocities inside a model seagrass bed Mitul Luhar,1

    E-Print Network [OSTI]

    Nepf, Heidi M.

    the seabed. Reduced resuspension improves water clarity, leading to greater light penetration and increased. By damping nearbed water velocities, seagrasses reduce local resuspension and promote the retention

  4. LIQUID-FLUIDIZED-BED HEAT' EXCHANGER FLOW DISTRIBUTION MODELS

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnical Report:Speeding accessby aLED Street LightingFrom theHighI _s - s i s i^ -RS 1

  5. THERMAL ENHANCEMENT CARTRIDGE HEATER MODIFIED TECH MOD TRITIUM HYDRIDE BED DEVELOPMENT PART I DESIGN AND FABRICATION

    SciTech Connect (OSTI)

    Klein, J.; Estochen, E.

    2014-03-06

    The Savannah River Site (SRS) tritium facilities have used 1{sup st} generation (Gen1) LaNi{sub 4.25}Al{sub 0.75} (LANA0.75) metal hydride storage beds for tritium absorption, storage, and desorption. The Gen1 design utilizes hot and cold nitrogen supplies to thermally cycle these beds. Second and 3{sup rd} generation (Gen2 and Gen3) storage bed designs include heat conducting foam and divider plates to spatially fix the hydride within the bed. For thermal cycling, the Gen2 and Gen 3 beds utilize internal electric heaters and glovebox atmosphere flow over the bed inside the bed external jacket for cooling. The currently installed Gen1 beds require replacement due to tritium aging effects on the LANA0.75 material, and cannot be replaced with Gen2 or Gen3 beds due to different designs of these beds. At the end of service life, Gen1 bed desorption efficiencies are limited by the upper temperature of hot nitrogen supply. To increase end-of-life desorption efficiency, the Gen1 bed design was modified, and a Thermal Enhancement Cartridge Heater Modified (TECH Mod) bed was developed. Internal electric cartridge heaters in the new design to improve end-of-life desorption, and also permit in-bed tritium accountability (IBA) calibration measurements to be made without the use of process tritium. Additional enhancements implemented into the TECH Mod design are also discussed.

  6. Biological consequences of Chernobyl: 20 years on

    E-Print Network [OSTI]

    Mousseau, Timothy A.

    have since shown associations between high and low levels of radiation and the abundance, distribution-level radiation has been defined as the dose below which it is not possible to detect adverse health effects, life history and mutation rates of plants and animals. However, this research is the consequence

  7. Transmission consequences of coinfection: cytokines writ large?

    E-Print Network [OSTI]

    Transmission consequences of coinfection: cytokines writ large? Andrea L. Graham1 , Isabella M between- host transmission. Cytokines, immune signalling mol- ecules with a fundamental role-host transmission represents a major challenge in parasite ecology and applied biomedicine [1­5]. Co- infection (see

  8. Coal hydrogenation and deashing in ebullated bed catalytic reactor

    DOE Patents [OSTI]

    Huibers, Derk T. A. (Pennington, NJ); Johanson, Edwin S. (Princeton, NJ)

    1983-01-01

    An improved process for hydrogenation of coal containing ash with agglomeration and removal of ash from an ebullated bed catalytic reactor to produce deashed hydrocarbon liquid and gas products. In the process, a flowable coal-oil slurry is reacted with hydrogen in an ebullated catalyst bed reaction zone at elevated temperature and pressure conditions. The upward velocity and viscosity of the reactor liquid are controlled so that a substantial portion of the ash released from the coal is agglomerated to form larger particles in the upper portion of the reactor above the catalyst bed, from which the agglomerated ash is separately withdrawn along with adhering reaction zone liquid. The resulting hydrogenated hydrocarbon effluent material product is phase separated to remove vapor fractions, after which any ash remaining in the liquid fraction can be removed to produce substantially ash-free coal-derived liquid products.

  9. Regeneration of lime from sulfates for fluidized-bed combustion

    DOE Patents [OSTI]

    Yang, Ralph T. (Middle Island, NY); Steinberg, Meyer (Huntington Station, NY)

    1980-01-01

    In a fluidized-bed combustor the evolving sulfur oxides are reacted with CaO to form calcium sulfate which is then decomposed in the presence of carbonaceous material, such as the fly ash recovered from the combustion, at temperatures of about 900.degree. to 1000.degree. C., to regenerate lime. The regenerated lime is then recycled to the fluidized bed combustor to further react with the evolving sulfur oxides. The lime regenerated in this manner is quite effective in removing the sulfur oxides.

  10. Pressurized fluidized-bed combustion technology exchange workshop

    SciTech Connect (OSTI)

    ,

    1980-04-01

    The pressurized fluidized-bed combustion technology exchange workshop was held June 5 and 6, 1979, at The Meadowlands Hilton Hotel, Secaucus, New Jersey. Eleven papers have been entered individually into EDB and ERA. The papers include reviews of the US DOE and EPRI programs in this area and papers by Swedish, West German, British and American organizations. The British papers concern the joint program of the USA, UK and FRG at Leatherhead. The key factor in several papers is the use of fluidized bed combustors, gas turbines, and steam turbines in combined-cycle power plants. One paper examines several combined-cycle alternatives. (LTN)

  11. Coal-feeding mechanism for a fluidized bed combustion chamber

    DOE Patents [OSTI]

    Gall, Robert L. (Morgantown, WV)

    1981-01-01

    The present invention is directed to a fuel-feeding mechanism for a fluidized bed combustor. In accordance with the present invention a perforated conveyor belt is utilized in place of the fixed grid normally disposed at the lower end of the fluidized bed combustion zone. The conveyor belt is fed with fuel, e.g. coal, at one end thereof so that the air passing through the perforations dislodges the coal from the belt and feeds the coal into the fluidized zone in a substantially uniform manner.

  12. The adiabatic adsorption-desorption characteristics of silica gel beds 

    E-Print Network [OSTI]

    Barker, James Marshall

    1979-01-01

    -desorpt1on characteristics of silica gel beds are i nvest1gated . The mathematical equations that descry 1 be desiccant bed behav1or are formulated and solved numer1cally us1ng f1nite difference methods. The equat1ons are derived such that both... of the finite d1fference program. The functional relationships are sufficiently accurate for most design purposes, and are r ead1 ly adaptable for use 1 n parametric studies of desiccant air condi t1 on1ng systems . DEDICATION Dedicated to My Parents...

  13. Fluidized-Bed Waste-Heat Recovery System Advances 

    E-Print Network [OSTI]

    Patch, K. D.; Cole, W. E.

    1986-01-01

    stream_source_info ESL-IE-86-06-09.pdf.txt stream_content_type text/plain stream_size 23561 Content-Encoding ISO-8859-1 stream_name ESL-IE-86-06-09.pdf.txt Content-Type text/plain; charset=ISO-8859-1 FLUIDIZED-BED WASTE-HEAT... RECOVERY SYSTEM ADVANCES Keith D. Patch William E. Cole Thermo Electron Corporation Waltham, Massachusetts ABSTRACT The Fluidized-Bed Waste-Heat Recovery (FBWHR) System is a combustion air preheater designed for existing unrecuperated...

  14. Very High Temperature Reactor (VHTR) Deep Burn Core and Fuel Analysis -- Complete Design Selection for the Pebble Bed Reactor

    SciTech Connect (OSTI)

    B. Boer; A. M. Ougouag

    2010-09-01

    The Deep-Burn (DB) concept focuses on the destruction of transuranic nuclides from used light water reactor fuel. These transuranic nuclides are incorporated into TRISO coated fuel particles and used in gas-cooled reactors with the aim of a fractional fuel burnup of 60 to 70% in fissions per initial metal atom (FIMA). This high performance is expected through the use of multiple recirculation passes of the fuel in pebble form without any physical or chemical changes between passes. In particular, the concept does not call for reprocessing of the fuel between passes. In principle, the DB pebble bed concept employs the same reactor designs as the presently envisioned low-enriched uranium core designs, such as the 400 MWth Pebble Bed Modular Reactor (PBMR-400). Although it has been shown in the previous Fiscal Year (2009) that a PuO2 fueled pebble bed reactor concept is viable, achieving a high fuel burnup, while remaining within safety-imposed prescribed operational limits for fuel temperature, power peaking and temperature reactivity feedback coefficients for the entire temperature range, is challenging. The presence of the isotopes 239-Pu, 240-Pu and 241-Pu that have resonances in the thermal energy range significantly modifies the neutron thermal energy spectrum as compared to a ”standard,” UO2-fueled core. Therefore, the DB pebble bed core exhibits a relatively hard neutron energy spectrum. However, regions within the pebble bed that are near the graphite reflectors experience a locally softer spectrum. This can lead to power and temperature peaking in these regions. Furthermore, a shift of the thermal energy spectrum with increasing temperature can lead to increased absorption in the resonances of the fissile Pu isotopes. This can lead to a positive temperature reactivity coefficient for the graphite moderator under certain operating conditions. The effort of this task in FY 2010 has focused on the optimization of the core to maximize the pebble discharge burnup level, while retaining its inherent safety characteristics. Using generic pebble bed reactor cores, this task will perform physics calculations to evaluate the capabilities of the pebble bed reactor to perform utilization and destruction of LWR used-fuel transuranics. The task will use established benchmarked models, and will introduce modeling advancements appropriate to the nature of the fuel considered (high TRU content and high burn-up).

  15. Sensitive response of the Greenland Ice Sheet to surface melt drainage over soft bed

    E-Print Network [OSTI]

    Bougamont, M. H.; Christoffersen, P.; Hubbard, A.. L..; Fitzpatrick, A.. A..; Doyle, S. H.; Carter, S. P.

    2014-09-29

    by frictional and geothermal heating accumulates at the 136 bed over the course of winter and is released together with the first SGL drainage 137 events. With either one of these factors included, our model was able to reproduce the 138 2010 spring... . Measurements of ice 492 deformation, temperature and cross-borehole conductivity in boreholes to the 493 bedrock. Journal Of Glaciology 48, 369-385 (2002). 494 25 Pimentel, S. & Flowers, G. E. A numerical study of hydrologically driven 495 glacier dynamics...

  16. Hydrocracking of heavy oils using an ebullated bed technology with recycle of unconverted bottom

    SciTech Connect (OSTI)

    Galiasso, R.; Gutierrez, M.; Caprioli, L.

    1986-01-01

    An hydrocracking process was studied to convert Cerro Negro heavy oil using an ebullated bed technology with recycle of uncoverted bottoms. Three levels of recycle were used to demonstrate its effect on the economy of the process. An apparent kinetics was developed for the properties studied and a CSTR model was used to simulate the hydrocracking reactor. The reactivity of the recycled decreases as a function of the number of pass and the level of conversion; the higher the recycle is the higher the catalyst consumption for constant level of conversion. There is an economic optimum level of recycle which depends on catalyst deactivation and the economic parameters, and properties of the feed.

  17. Explaining the causes and consequences of internationally monitored elections

    E-Print Network [OSTI]

    Hyde, Susan Dayton

    2006-01-01

    2003. "Electoral Fraud: Causes, Types, and Consequences."Observing Norms: Explaining the Causes and Consequences ofW. 1998. "The International Causes of Democratization, 1974-

  18. Causes and consequences of unsteady crustal magma transport

    E-Print Network [OSTI]

    Karlstrom, Leif

    2011-01-01

    O. D. Sevre. Dynamical causes for incipient magma chambersCauses and consequences of unsteady crustal magma transportPhilip S Marcus Fall 2011 Causes and consequences of

  19. NNSA Releases Pictures, Video of Consequence Management Response...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Releases Pictures, Video of Consequence Management Response Teams Deploying to Japan NNSA Releases Pictures, Video of Consequence Management Response Teams Deploying to Japan March...

  20. Holographic Consequences of a No Transmission Principle

    E-Print Network [OSTI]

    Netta Engelhardt; Gary T. Horowitz

    2015-10-12

    Two quantum field theories whose Hilbert spaces do not overlap cannot transmit a signal to one another. From this simple principle, we deduce some highly nontrivial consequences for holographic quantum gravity. These include: (1) certain cosmological bounces are forbidden, (2) generic singularities inside black holes cannot be resolved, and (3) traversable wormholes do not exist. At the classical level, this principle rules out certain types of naked singularities and suggests that new singularity theorems should exist.

  1. Holographic Consequences of a No Transmission Principle

    E-Print Network [OSTI]

    Engelhardt, Netta

    2015-01-01

    Two quantum field theories whose Hilbert spaces do not overlap cannot transmit energy to one another. From this simple principle, we deduce some highly nontrivial consequences for holographic quantum gravity. These include: (1) certain cosmological bounces are forbidden, (2) generic singularities inside black holes cannot be resolved, and (3) traversable wormholes do not exist. At the classical level, this principle rules out certain types of naked singularities and suggests that new singularity theorems should exist.

  2. Packed bed reactor for photochemical .sup.196 Hg isotope separation

    DOE Patents [OSTI]

    Grossman, Mark W. (Belmont, MA); Speer, Richard (Reading, MA)

    1992-01-01

    Straight tubes and randomly oriented pieces of tubing having been employed in a photochemical mercury enrichment reactor and have been found to improve the enrichment factor (E) and utilization (U) compared to a non-packed reactor. One preferred embodiment of this system uses a moving bed (via gravity) for random packing.

  3. Arkosic conglomerate beds in Mason, Menard, and Kimble counties, Texas 

    E-Print Network [OSTI]

    Rogers, Luther Franklin

    1955-01-01

    o o o ~ METHODS ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ o ~ ~ ~ ~ ~ 2 ~ ~ ~ ~ 3 DESCRIPTION OF THZ ROCK ~, ~ ~, ~ ~ ~ ~ ~ . ~. . . ~ GENERAL GEOLOGIC RELATIONS ~ ~, . . . . . . , ~ ~ 4. THICKNESS AND BEDDING ~ ~ ~ o o o o . o o o o ~ ~ 7 LITHOLOGY... ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 7 CLASTICS AND TIIEIR SOURCES . . . . ~ ~ . . ~ 7 CANTING NATERIALS AND TOPOGRAPHIC EXPRESS ION ~ o ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ o ~ ~ ~ 1O AGE ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ o ~ 15 CONCLUSIONS o o ~ ~ ~ ~ o ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 18...

  4. Paleoecology of the Greater Phyllopod Bed community, Burgess Shale

    E-Print Network [OSTI]

    Jackson, Don

    Paleoecology of the Greater Phyllopod Bed community, Burgess Shale Jean-Bernard Caron , Donald A and composition, ecological attributes, and environmental influences for the Middle Cambrian Burgess Shale ecosystems further suggest the Burgess Shale community was probably highly dependent on immigration from

  5. Method for using fast fluidized bed dry bottom coal gasification

    DOE Patents [OSTI]

    Snell, George J. (Fords, NJ); Kydd, Paul H. (Lawrenceville, NJ)

    1983-01-01

    Carbonaceous solid material such as coal is gasified in a fast fluidized bed gasification system utilizing dual fluidized beds of hot char. The coal in particulate form is introduced along with oxygen-containing gas and steam into the fast fluidized bed gasification zone of a gasifier assembly wherein the upward superficial gas velocity exceeds about 5.0 ft/sec and temperature is 1500.degree.-1850.degree. F. The resulting effluent gas and substantial char are passed through a primary cyclone separator, from which char solids are returned to the fluidized bed. Gas from the primary cyclone separator is passed to a secondary cyclone separator, from which remaining fine char solids are returned through an injection nozzle together with additional steam and oxygen-containing gas to an oxidation zone located at the bottom of the gasifier, wherein the upward gas velocity ranges from about 3-15 ft/sec and is maintained at 1600.degree.-200.degree. F. temperature. This gasification arrangement provides for increased utilization of the secondary char material to produce higher overall carbon conversion and product yields in the process.

  6. Westinghouse standleg moving granular bed filter development program

    SciTech Connect (OSTI)

    Newby, R.A.; Yang, W.C.; Smeltzer, E.E.; Lippert, T.E.

    1994-10-01

    Advanced, coal-based, power plants, such as IGCC and Advanced-PFBC, are currently nearing commercial demonstration. These power plant technologies require hot gas filtration as part of their gas cleaning trains. Ceramic barrier filters are the major filter candidates being developed for these hot gas cleaning applications. While ceramic barrier filters achieve high levels of particle removal, there are concerns for their reliability and operability. An alternative hot gas filtration technology is the moving granular bed filter. These systems are at a lower state of development than ceramic barrier filters, and their effectiveness as filters is still in question. Their apparent attributes, result from their much less severe mechanical design and materials constraints, and the potential for more reliable, failure-free particle removal operation. The standleg moving granular-bed filter (SMGBF) system, is a compact unit that uses cocurrent gas-pellet contacting in an arrangement that greatly simplifies and enhances the distribution of dirty, process gas to the moving bed and allows effective disengagement of clean gas from the moving bed. This paper describes the equipment and process test results.

  7. MIT PEBBLE BED REACTOR PROJECT ANDREW C. KADAK

    E-Print Network [OSTI]

    , including the AP-600, the advanced boiling water reactor (ABWR) and the standard PWR designs offered of existing light water reactors and plans for evolutionary plants that were being considered at the timeMIT PEBBLE BED REACTOR PROJECT ANDREW C. KADAK Nuclear Science and Engineering Department

  8. LARGE EDDY SIMULATION OF TURBULENT BOUNDARY LAYERS OVER ROUGH BEDS

    E-Print Network [OSTI]

    Pawlak, Geno

    that determines the response of the boundary layer is not clear. One method to characterize the irregular nature with different spectral slopes using 2D 10 % loading square waves as basis functions. These square waves can) is then used to simulate the turbulent boundary layer over the rough beds. The LES solver is first validated

  9. Secular Sediment Waves, Channel Bed Waves, and Legacy Sediment

    E-Print Network [OSTI]

    James, L. Allan

    Secular Sediment Waves, Channel Bed Waves, and Legacy Sediment L. Allan James* Geography Department, University South Carolina Abstract The concept of sediment waves is reviewed and clarifications are proposed for nomenclature con- cerning vertical channel responses to large fluvial sediment fluxes over a period of a decade

  10. Spectral Analysis of Thinning Beds Using Ground Penetrating Radar 

    E-Print Network [OSTI]

    Francese, Renee Rose

    2012-07-16

    Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2. BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1 Electromagnetic Theory... and Amundsen, 2005]. In this study, GPR attributes will be analyzed to discern lateral variations in subsurface electromagnetic properties associated with thinning beds. 4 The fundamental basis for AVO analysis involves the Zoeppritz equations, which are a...

  11. Pebble Bed Reactor review update. Fiscal year 1979 annual report

    SciTech Connect (OSTI)

    Not Available

    1980-01-01

    Updated information is presented on the Pebble Bed Reactor (PBR) concept being developed in the Federal Republic of Germany for electricity generation and process heat applications. Information is presented concerning nuclear analysis and core performance, fuel cycle evaluation, reactor internals, and safety and availability.

  12. Channel bed evolution and sediment transport under declining sand inputs

    E-Print Network [OSTI]

    Montgomery, David R.

    Channel bed evolution and sediment transport under declining sand inputs Karen B. Gran,1,2 David R structure development and sediment transport as sand inputs decline. On the Pasig-Potrero River, we investigated channel recovery following emplacement of sand-rich pyroclastic deposits in the 1991 eruption

  13. Isolated thermocouple amplifier system for stirred fixed-bed gasifier

    DOE Patents [OSTI]

    Fasching, George E. (Morgantown, WV)

    1992-01-01

    A sensing system is provided for determining the bed temperature profile of the bed of a stirred, fixed-bed gasifier including a plurality of temperature sensors for sensing the bed temperature at different levels, a transmitter for transmitting data based on the outputs of the sensors to a remote operator's station, and a battery-based power supply. The system includes an isolation amplifier system comprising a plurality of isolation amplifier circuits for amplifying the outputs of the individual sensors. The isolation amplifier circuits each comprise an isolation operational amplifier connected to a sensor; a first "flying capacitor" circuit for, in operation, controlling the application of power from the power supply to the isolation amplifier; an output sample and hold circuit connected to the transmitter; a second "flying capacitor" circuit for, in operation, controlling the transfer of the output of the isolation amplifier to the sample and hold circuit; and a timing and control circuit for activating the first and second capacitor circuits in a predetermined timed sequence.

  14. Modularity of the MIT Pebble Bed Reactor for use by the commercial power industry

    E-Print Network [OSTI]

    Hanlon-Hyssong, Jaime E

    2008-01-01

    The Modular Pebble Bed Reactor is a small high temperature helium cooled reactor that is being considered for both electric power and hydrogen production. Pebble bed reactors are being developed in South Africa, China and ...

  15. Bedding and Seasonal Effects on Chemical and Bacterial Properties of Feedlot Cattle Manure

    E-Print Network [OSTI]

    Selinger, Brent

    cattle (Bos wood-chip bedding in their operations. Wood chips gen-taurus) feedlot in southern Alberta whereas season affected all four groups. Num- in straw and wood-chip bedding suggest there is a poten

  16. New Zero Net-Energy Facility: A Test Bed for Home Efficiency...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    New Zero Net-Energy Facility: A Test Bed for Home Efficiency New Zero Net-Energy Facility: A Test Bed for Home Efficiency September 17, 2012 - 2:34pm Addthis Deputy Assistant...

  17. DOE/OE National SCADA Test Bed Fiscal Year 2009 Work Plan | Department...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    DOEOE National SCADA Test Bed Fiscal Year 2009 Work Plan DOEOE National SCADA Test Bed Fiscal Year 2009 Work Plan This document is designed to help guide and strengthen the DOE...

  18. Estimation of the bed shear stress in vegetated and bare channels

    E-Print Network [OSTI]

    Yang, Qingjun (Judy Qingjun)

    2015-01-01

    The shear stress at the bed of a channel influences important benthic processes such as sediment transport. Several methods exist to estimate the bed shear stress in bare channels without vegetation, but most of these are ...

  19. MASS TRANSFER CONTROLLED REACTIONS IN PACKED BEDS AT LOW REYNOLDS NUMBERS

    E-Print Network [OSTI]

    Fedkiw, Peter S.

    2011-01-01

    beds. The Effect of Flow Maldistribution in a Packed Bed onthe effect of flow maldistribution in an array of tubes. Histhis idea of flow maldistribution is expanded upon, and in

  20. EXPERIMENTAL & NUMERICAL STUDY OF CERAMIC BREEDER PEBBLE BED THERMAL DEFORMATION BEHAVIOR

    E-Print Network [OSTI]

    Abdou, Mohamed

    EXPERIMENTAL & NUMERICAL STUDY OF CERAMIC BREEDER PEBBLE BED THERMAL DEFORMATION BEHAVIOR Zhiyong breeder blanket design, the ceramic breeder pebble bed system, which is typically operated's blanket. Ceramic pebbles are promising candidates because it can overcome the inherent brittleness

  1. Unintended consequences of atmospheric injection of sulphate aerosols.

    SciTech Connect (OSTI)

    Brady, Patrick Vane; Kobos, Peter Holmes; Goldstein, Barry

    2010-10-01

    Most climate scientists believe that climate geoengineering is best considered as a potential complement to the mitigation of CO{sub 2} emissions, rather than as an alternative to it. Strong mitigation could achieve the equivalent of up to -4Wm{sup -2} radiative forcing on the century timescale, relative to a worst case scenario for rising CO{sub 2}. However, to tackle the remaining 3Wm{sup -2}, which are likely even in a best case scenario of strongly mitigated CO{sub 2} releases, a number of geoengineering options show promise. Injecting stratospheric aerosols is one of the least expensive and, potentially, most effective approaches and for that reason an examination of the possible unintended consequences of the implementation of atmospheric injections of sulphate aerosols was made. Chief among these are: reductions in rainfall, slowing of atmospheric ozone rebound, and differential changes in weather patterns. At the same time, there will be an increase in plant productivity. Lastly, because atmospheric sulphate injection would not mitigate ocean acidification, another side effect of fossil fuel burning, it would provide only a partial solution. Future research should aim at ameliorating the possible negative unintended consequences of atmospheric injections of sulphate injection. This might include modeling the optimum rate and particle type and size of aerosol injection, as well as the latitudinal, longitudinal and altitude of injection sites, to balance radiative forcing to decrease negative regional impacts. Similarly, future research might include modeling the optimum rate of decrease and location of injection sites to be closed to reduce or slow rapid warming upon aerosol injection cessation. A fruitful area for future research might be system modeling to enhance the possible positive increases in agricultural productivity. All such modeling must be supported by data collection and laboratory and field testing to enable iterative modeling to increase the accuracy and precision of the models, while reducing epistemic uncertainties.

  2. Pulsed atmospheric fluidized bed combustion. Technical progress report, January 1995--April 1995

    SciTech Connect (OSTI)

    NONE

    1995-05-31

    Progress is reported on the design of a pulsed fluidized bed combustor and component, fabrication, and construction site activities.

  3. Task 3.8 - pressurized fluidized-bed combustion

    SciTech Connect (OSTI)

    NONE

    1995-03-01

    The focus of this work on pressurized fluidized-bed combustion (PFBC) is the development of sorbents for in-bed alkali control. The goal is to generate fundamental process information for development of a second-generation PFBC. Immediate objectives focus on the performance of sulfur sorbents, fate of alkali, and the Resource Conservation and Recovery Act (RCRA) heavy metals. The studies reported here focus on emission control strategies applied in the bed. Data from shakedown testing, alkali sampling, sulfur sorbent performance tests, and refuse-derived fuel (RDF) and lignite combustion tests are presented in detail. Initial results from the characterization of alkali gettering indicate that in-bed getters can remove a significant amount of alkali from the bed. Using kaolin as a sorbent, sodium levels in the flue gas were reduced from 3.6 ppm to less than 0.22 ppm. Sulfur was also reduced by 60% using the kaolin sorbent. Preliminary sulfur sorbent testing, which was designed to develop a reliable technique to predice sorbent performance, indicate that although the total sulfur capture is significantly lower than that observed in a full-scale PFBC, the emission trends are similar. RDF and RDF-lignite fuels had combustion efficiencies exceeding 99.0% in all test cases. Sulfur dioxide emission was significantly lower for the RDF fuels than for lignite fuel alone. Nitrogen oxide emission was also lower for the RDF-based fuels than for the lignite fuel. Both emission gases were well below current regulatory limits. Carbon monoxide and hydrocarbon emissions appeared to be slightly higher for the fuels containing RDF, but were below 9 ppm for the worst case. Analysis of volatile organic compound emission does not indicate an emission problem for these fuels. Chromium appears to be the only RCRA metal that might present some disposal problem; however, processing of the RDF with the wet resource recovery method should reduce chromium levels. 2 refs., 13 figs., 15 tabs.

  4. Oxidative stress in kidney transplantation: causes, consequences, and potential treatment.

    E-Print Network [OSTI]

    Nafar, Mohsen; Sahraei, Zahra; Salamzadeh, Jamshid; Samavat, Shiva; Vaziri, Nosartolah D

    2011-01-01

    Transplantation Review Causes, Consequences, and Potentialnitrogenous free radicals causes tissue injury and impairs

  5. Method and apparatus for enhancing the desulfurization of hot coal gas in a fluid-bed coal gasifier

    DOE Patents [OSTI]

    Grindley, T.

    1988-04-05

    A process and apparatus for providing additional desulfurization of the hot gas produced in a fluid-bed coal gasifier, within the gasifier is described. A fluid-bed of iron oxide is located inside the gasifier above the gasification bed in a fluid-bed coal gasifier in which in-bed desulfurization by lime/limestone takes place. The product gases leave the gasification bed typically at 1600 to 1800 F and are partially quenched with water to 1000 to 1200 F before entering the iron oxide bed. The iron oxide bed provides additional desulfurization beyond that provided by the lime /limestone. 1 fig.

  6. High-resolution bed topography mapping of Russell Glacier, Greenland, inferred from Operation IceBridge data

    E-Print Network [OSTI]

    2013-01-01

    High-resolution bed topography mapping of Russell Glacier,for generalizing topography to grids while preservingRasmussen LA (1988) Bed topography and mass-balance

  7. Analysis of granular flow in a pebble-bed nuclear reactor Chris H. Rycroft,1

    E-Print Network [OSTI]

    Bazant, Martin Z.

    Analysis of granular flow in a pebble-bed nuclear reactor Chris H. Rycroft,1 Gary S. Grest,2 James February 2006; published 24 August 2006 Pebble-bed nuclear reactor technology, which is currently being States, the Modular Pebble Bed Reactor MPBR 4,8 is a candidate for the next generation nuclear plant

  8. Characterizing the Hydrodynamics of Bubbling Fluidized Beds with Multivariate Pressure Measurements

    E-Print Network [OSTI]

    Tennessee, University of

    Characterizing the Hydrodynamics of Bubbling Fluidized Beds with Multivariate Pressure Measurements mounted on the walls of a bubbling fluidized bed. Our objective was to identify multivariate dynamic of bubbling fluidized beds with multivariate pressure measurements. 2000 AIChE Annual Meeting (Los Angeles

  9. Thermal and mechanical properties of ceramic blanket particle bed materials: Numerical derivation

    E-Print Network [OSTI]

    Abdou, Mohamed

    Thermal and mechanical properties of ceramic blanket particle bed materials: Numerical derivation thermal and mechanical properties of the ceramic breeder blanket particle bed materials is presented caused by the high thermal expansion of the breeder particle bed material could lead to ceramic par

  10. MFIX simulation of NETL/PSRI challenge problem of circulating fluidized bed

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Li, Tingwen; Dietiker, Jean-François; Shahnam, Mehrdad

    2012-12-01

    In this paper, numerical simulations of NETL/PSRI challenge problem of circulating fluidized bed (CFB) using the open-source code Multiphase Flow with Interphase eXchange (MFIX) are reported. Two rounds of simulation results are reported including the first-round blind test and the second-round modeling refinement. Three-dimensional high fidelity simulations are conducted to model a 12-inch diameter pilot-scale CFB riser. Detailed comparisons between numerical results and experimental data are made with respect to axial pressure gradient profile, radial profiles of solids velocity and solids mass flux along different radial directions at various elevations for operating conditions covering different fluidization regimes. Overall, the numericalmore »results show that CFD can predict the complex gas–solids flow behavior in the CFB riser reasonably well. In addition, lessons learnt from modeling this challenge problem are presented.« less

  11. MFIX simulation of NETL/PSRI challenge problem of circulating fluidized bed

    SciTech Connect (OSTI)

    Li, Tingwen; Dietiker, Jean-François; Shahnam, Mehrdad

    2012-12-01

    In this paper, numerical simulations of NETL/PSRI challenge problem of circulating fluidized bed (CFB) using the open-source code Multiphase Flow with Interphase eXchange (MFIX) are reported. Two rounds of simulation results are reported including the first-round blind test and the second-round modeling refinement. Three-dimensional high fidelity simulations are conducted to model a 12-inch diameter pilot-scale CFB riser. Detailed comparisons between numerical results and experimental data are made with respect to axial pressure gradient profile, radial profiles of solids velocity and solids mass flux along different radial directions at various elevations for operating conditions covering different fluidization regimes. Overall, the numerical results show that CFD can predict the complex gas–solids flow behavior in the CFB riser reasonably well. In addition, lessons learnt from modeling this challenge problem are presented.

  12. Characterization of Biofilm in 200W Fluidized Bed Reactors

    SciTech Connect (OSTI)

    Lee, Michelle H.; Saurey, Sabrina D.; Lee, Brady D.; Parker, Kent E.; Eisenhauer, Emalee ER; Cordova, Elsa A.; Golovich, Elizabeth C.

    2014-09-29

    Contaminated groundwater beneath the 200 West Area at the Hanford Site in Southeast Washington is currently being treated using a pump and treat system to remove organics, inorganics, radionuclides, and metals. A granular activated carbon-based fluidized bed reactor (FBR) has been added to remove nitrate, hexavalent chromium and carbon tetrachloride. Initial analytical results indicated the microorganisms effectively reduced many of the contaminants to less than cleanup levels. However shortly thereafter operational upsets of the FBR include carbon carry over, over production of microbial extracellular polymeric substance (biofilm) materials, and over production of hydrogen sulfide. As a result detailed investigations were undertaken to understand the functional diversity and activity of the microbial community present in the FBR over time. Molecular analyses including terminal restriction fragment length polymorphism analysis, quantitative polymerase chain reaction and fluorescent in situ hybridization analyses were performed on the microbial community extracted from the biofilm within the bed and from the inoculum, to determine functional dynamics of the FBR bed over time and following operational changes. Findings from these analyses indicated: 1) the microbial community within the bed was completely different than community used for inoculation, and was likely from the groundwater; 2) analyses early in the testing showed an FBR community dominated by a few Curvibacter and Flavobacterium species; 3) the final sample taken indicated that the microbial community in the FBR bed had become more diverse; and 4) qPCR analyses indicated that bacteria involved in nitrogen cycling, including denitrifiers and anaerobic ammonia oxidizing bacteria, were dominant in the bed. These results indicate that molecular tools can be powerful for determining functional diversity within FBR type reactors. Coupled with micronutrient, influent and effluent chemistry evaluations, a more complete understanding of the balance between system additions (nutrients, groundwater) and biology can be achieved, thus increasing long-term predictions of performance. These analyses uniquely provide information that can be used in optimizing the overall performance, efficiency, and stability of the system both in real time as well as over the long-term, as the system design is altered or improved and/or new streams are added.

  13. Controlled waste-oil biodegradation at existing drying beds

    SciTech Connect (OSTI)

    Hary, L.F.

    1982-01-01

    A feasibility study at the Portsmouth Uranium Enrichment Facility to determine if sludge drying beds at a sewage treatment plant could be used as controlled waste oil biodegradation plots has been completed. A greenhouse-like enclosure would be constructed over three 9.1 meter by 21.3 meter beds to allow for year-round use, and any waste oil runoff would be collected by existing leachate piping. It has been determined that this proposed facility could dispose of existing radioactive waste oil generation (7200 liters/year) from the Gaseous Diffusion Plant (GDP); however, it would be inadequate to handle radioactive waste oils from the new Gas Centrifuge Enrichment Plant (GCEP) as well. The study reviewed nuclear criticality constraints, biodegradation technology, and the capital cost for an enclosed biodegradation facility.

  14. Current state of atmospheric fluidized-bed combustion technology

    SciTech Connect (OSTI)

    Not Available

    1989-01-01

    This paper examines atmospheric fluidized-bed combustion (AFBC) technology, a coal burning method that has several environmental and technical advantages over the more conventional technologies, such as pulverized-coal methods. The AFBC approach injects an air stream into a boiler in such a way that it mixes with solid fuel and sorbent to create a dense phase region or fluidized bed. This method makes it possible to use a much wider range of low-quality fuels and to burn them at lower temperatures with less pollutant by-product. The paper presents a comprehensive overview of AFBC technology to date. It includes worldwide development of this technology since the 1950s necessary to meet ever-stricter emissions requirements while providing greater fuel flexibility.

  15. Grate assembly for fixed-bed coal gasifier

    DOE Patents [OSTI]

    Notestein, John E. (Morgantown, WV)

    1993-01-01

    A grate assembly for a coal gasifier of a moving-bed or fixed-bed type is provided for crushing agglomerates of solid material such as clinkers, tailoring the radial distribution of reactant gases entering the gasification reaction zone, and control of the radial distribution of downwardly moving solid velocities in the gasification and combustion zone. The clinker crushing is provided by pinching clinkers between vertically oriented stationary bars and angled bars supported on the upper surface of a rotating conical grate. The distribution of the reactant gases is provided by the selective positioning of horizontally oriented passageways extending through the grate. The radial distribution of the solids is provided by mounting a vertically and generally radially extending scoop mechanism on the upper surface of the grate near the apex thereof.

  16. Combustion of refuse derived fuel in a fluidized bed

    SciTech Connect (OSTI)

    Piao, Guilin; Aono, Shigeru; Mori, Shigekatsu; Deguchi, Seiichi; Fujima, Yukihisa; Kondoh, Motohiro; Yamaguchi, Masataka

    1998-12-31

    Power generation from Refuse Derived Fuel (RDF) is an attractive utilization technology of municipal solid waste. To explain the behavior of RDF-fired fluidized bed incinerator, the commercial size RDF was continuously burnt in a 30 x 30 cm bubbling type fluidized-bed combustor. It was found that 12 kg/h of RDF feed rate was too high feed for this test unit and the Co level was higher than 500 ppm. However, 10 kg/h of RDF was a proper feed rate and the Co level was kept under 150 ppm. Secondary air injection and changing air ratio from the pipe grid were effective for the complete combustion of RDE. It was also found that HCl concentration in flue gas was controlled by the calcium component contained in RDF and its level was decreased with decreasing the combustor temperature.

  17. Fischer-Tropsch synthesis from a low H/sub 2/:CO gas in a dry fluidized-bed system. Volume 2. Development of microreactor systems for unsteady-state Fischer-Tropsch synthesis. Final technical report. [408 references

    SciTech Connect (OSTI)

    Whiting, G.K.; Liu, Y.A.; Squires, A.M.

    1986-10-01

    Vibrofluidized microreactor systems have been developed for studies of unsteady-state Fischer-Tropsch synthesis. This development is aimed at preventing carbon deposition on a fused-iron catalyst in a novel reactor called the ''heat tray.'' This reactor involves a supernatant gas flowing over a shallow fluidized bed of catalyst particles. Three systems were built: (1) a vibrofluidized-bed microreactor system for obtaining baseline carbon deposition information under industrially important reaction conditions; (2) a sliding-plug vibrofluidized-bed microreactor system for rapid switching of feed gases in the F-T synthesis; and (3) a cold-flow microreactor model for studying the gas mixing characteristics of the sliding-plug vibrofluidized-bed microreactor. The results show that catalyst defluidization occurred under steady-state synthesis conditions below 395 C using a feed gas of H/sub 2//CO ratio of 2:1 or less. Above 395 C, the probability of hydrocarbon chain growth (..cap alpha.. < 0.50 to prevent accumulation of high-molecular-weight species that cause defluidization. Carbon deposition was rapid above 395 C when a feed gas of H/sub 2//CO ratio of 2:1 or less was used. Cold-flow microreactor model studies show that rapid (on the order of seconds), quantitative switching of feed gases over a vibrofluidized bed of catalyst could be achieved. Vibrofluidization of the catalyst bed induced little backmixing of feed gas over the investigated flow-rate range of 417 to 1650 actual mm/sup 3//s. Further, cold-flow microreactor model studies showed intense solid mixing when a bed of fused-iron catalyst (150 to 300 microns) was vibrofluidized at 24 cycles per second with a peak-to-peak amplitude of 4 mm. The development of the microreactor systems provided an easy way of accurately determining integral fluid-bed kinetics in a laboratory reactor. 408 refs., 156 figs., 27 tabs.

  18. MODELING THE CONSEQUENCES OF TONGUE SURGERY ON TONGUE

    E-Print Network [OSTI]

    Payan, Yohan

    of the genioglossus muscle was removed as well as the totality of two major muscles of the mouth floor, namely the impact of tongue and mouth floor surgery on tongue mobility. The ultimate objective of this project of the tongue and of the mouth floor that matches the anatomical characteristics of each patient specific oral

  19. Statistical surrogate models for prediction of high-consequence climate

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnical Report:Speeding access toSmallTechnicalSheldon Glashow and-D Seismicf!\Jl~~ If

  20. Statistical Surrogate Models for Estimating Probability of High-Consequence

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail. (Conference)Feedback System in thewitnessChiralTechnical

  1. Statistical surrogate models for prediction of high-consequence climate

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail. (Conference)Feedback System in thewitnessChiralTechnicalchange. (Technical Report) |

  2. Pulsed atmospheric fluidized bed combustor apparatus and process

    DOE Patents [OSTI]

    Mansour, Momtaz N. (Columbia, MD)

    1992-01-01

    A pulsed atmospheric fluidized bed reactor system is disclosed and claimed along with a process for utilization of same for the combustion of, e.g. high sulfur content coal. The system affords a economical, ecologically acceptable alternative to oil and gas fired combustors. The apparatus may also be employed for endothermic reaction, combustion of waste products, e.g. organic and medical waste, drying, calcining and the like.

  3. Inclined fluidized bed system for drying fine coal

    DOE Patents [OSTI]

    Cha, Chang Y. (Golden, CO); Merriam, Norman W. (Laramie, WY); Boysen, John E. (Laramie, WY)

    1992-02-11

    Coal is processed in an inclined fluidized bed dryer operated in a plug-flow manner with zonal temperature and composition control, and an inert fluidizing gas, such as carbon dioxide or combustion gas. Recycled carbon dioxide, which is used for drying, pyrolysis, quenching, and cooling, is produced by partial decarboxylation of the coal. The coal is heated sufficiently to mobilize coal tar by further pyrolysis, which seals micropores upon quenching. Further cooling with carbon dioxide enhances stabilization.

  4. Prostate Bed Motion During Intensity-Modulated Radiotherapy Treatment

    SciTech Connect (OSTI)

    Klayton, Tracy; Price, Robert; Buyyounouski, Mark K.; Sobczak, Mark; Greenberg, Richard; Li, Jinsheng; Keller, Lanea; Sopka, Dennis; Kutikov, Alexander; Horwitz, Eric M.

    2012-09-01

    Purpose: Conformal radiation therapy in the postprostatectomy setting requires accurate setup and localization of the prostatic fossa. In this series, we report prostate bed localization and motion characteristics, using data collected from implanted radiofrequency transponders. Methods and Materials: The Calypso four-dimensional localization system uses three implanted radiofrequency transponders for daily target localization and real-time tracking throughout a course of radiation therapy. We reviewed the localization and tracking reports for 20 patients who received ultrasonography-guided placement of Calypso transponders within the prostate bed prior to a course of intensity-modulated radiation therapy at Fox Chase Cancer Center. Results: At localization, prostate bed displacement relative to bony anatomy exceeded 5 mm in 9% of fractions in the anterior-posterior (A-P) direction and 21% of fractions in the superior-inferior (S-I) direction. The three-dimensional vector length from skin marks to Calypso alignment exceeded 1 cm in 24% of all 652 fractions with available setup data. During treatment, the target exceeded the 5-mm tracking limit for at least 30 sec in 11% of all fractions, generally in the A-P or S-I direction. In the A-P direction, target motion was twice as likely to move posteriorly, toward the rectum, than anteriorly. Fifteen percent of all treatments were interrupted for repositioning, and 70% of patients were repositioned at least once during their treatment course. Conclusion: Set-up errors and motion of the prostatic fossa during radiotherapy are nontrivial, leading to potential undertreatment of target and excess normal tissue toxicity if not taken into account during treatment planning. Localization and real-time tracking of the prostate bed via implanted Calypso transponders can be used to improve the accuracy of plan delivery.

  5. Fluidized bed gasification ash reduction and removal system

    DOE Patents [OSTI]

    Schenone, Carl E. (Madison, PA); Rosinski, Joseph (Vanderbilt, PA)

    1984-02-28

    In a fluidized bed gasification system an ash removal system to reduce the particulate ash to a maximum size or smaller, allow the ash to cool to a temperature lower than the gasifier and remove the ash from the gasifier system. The system consists of a crusher, a container containing level probes and a means for controlling the rotational speed of the crusher based on the level of ash within the container.

  6. Fluidized bed gasification ash reduction and removal process

    DOE Patents [OSTI]

    Schenone, Carl E. (Madison, PA); Rosinski, Joseph (Vanderbilt, PA)

    1984-12-04

    In a fluidized bed gasification system an ash removal system to reduce the particulate ash to a maximum size or smaller, allow the ash to cool to a temperature lower than the gasifier and remove the ash from the gasifier system. The system consists of a crusher, a container containing level probes and a means for controlling the rotational speed of the crusher based on the level of ash within the container.

  7. Environmental consequences of energy production: Proceedings

    SciTech Connect (OSTI)

    none,

    1989-01-01

    The Seventeenth Annual Illinois Energy conference entitled Environmental consequences of Energy Production was held in Chicago, Illinois on October 19-20, 1989. The purpose of the meeting was to provide a forum for exchange of information on the technical, economic and institutional issues surrounding energy production and related environmental problems. The conference program was developed by a planning committee which included Illinois energy and environmental specialists from the major sectors including energy industries, environmental organizations, research universities, utility companies, federal, state and local government agencies, and public interest groups. The conference included presentations on four major topic areas. The issue areas were: urban pollution: where are we now and what needs to be done in the future; the acid rain problem: implications of proposed federal legislation on the Midwest; global warming: an update on the scientific debate; and strategies to minimize environmental damage. Separate abstracts have been prepared for the individual presentations. (FL)

  8. Partisan Sharing: Facebook Evidence and Societal Consequences

    E-Print Network [OSTI]

    An, Jisun; Crowcroft, Jon

    2014-01-01

    The hypothesis of selective exposure assumes that people seek out information that supports their views and eschew information that conflicts with their beliefs, and that has negative consequences on our society. Few researchers have recently found counter evidence of selective exposure in social media: users are exposed to politically diverse articles. No work has looked at what happens after exposure, particularly how individuals react to such exposure, though. Users might well be exposed to diverse articles but share only the partisan ones. To test this, we study partisan sharing on Facebook: the tendency for users to predominantly share like-minded news articles and avoid conflicting ones. We verified four main hypotheses. That is, whether partisan sharing: 1) exists at all; 2) changes across individuals (e.g., depending on their interest in politics); 3) changes over time (e.g., around elections); and 4) changes depending on perceived importance of topics. We indeed find strong evidence for partisan shar...

  9. A NEW INTERPHASE FORCE IN TWO-PHASE FLUIDIZED BEDS

    SciTech Connect (OSTI)

    D. ZHANG; W. VANDERHEYDEN

    2001-05-01

    Mesoscale structures such as particle clusters have been observed both in experiments and in numerical simulations of circulating fluidized beds. In a numerical simulation, in order to account for the effects of such mesoscale structures, the computational grids have to be fine enough. The use of such fine grids is impractical in engineering applications due to excessive computational costs. To predict the macroscopic behavior of a fluidized bed with reasonable computation cost, they perform a second average over the averaged equations for two-phase flows. A mesoscale inter-phase exchange force is found to be the correlation of the particle volume fraction and the pressure gradient. This force is related to the mesoscale added mass of the two-phase flow. Typically, added mass for particle scale interactions is negligible in gas-solid flows since the gas density is small compared to density of solid particles. However, for a mesoscale structure, such as a bubble, the surrounding media is the mixture of gas and particles. The surrounding fluid density experienced by the mesoscale structure is the density of the surrounding mixture. Therefore, the added mass of a mesoscale structure, such as bubbles, cannot be neglected. The property of this new force is studied based on the numerical simulation of a fluidized bed using high grid resolution. It is shown that this force is important in the region where the particle volume fraction is high. The effects of the inhomogeneity to the interphase drag are also studied.

  10. Fluidized-bed combustion of scrap tires: Technical note

    SciTech Connect (OSTI)

    Shang, J.Y.; Mei, J.S.; Notestein, J.E.

    1981-10-01

    An introduction to fluidized-bed combustion (FBC) is presented in Section 2.0. Based on this discussion of its technical development, FBC is then presented as a means of scrap tire disposal. In Section 3.0, scrap tire disposal is reviewed in the categories of (1) physical applications, (2) chemical applications, (3) pyrolysis, and (4) incineration for thermal energy recovery. Scrap tire disposal is reviewed on the basis of (1) environmental acceptability, (2) conservation of resources, (3) impact on existing industries, (4) operational feasibility, and (5) special features. The focus of this report is the fluidized-bed incineration of scrap tires for thermal energy recovery. The factors that affect scrap tire combustion are discussed in Section 4.0. These factors are (1) agitation, (2) temperature, (3) excess air, (4) residence time, (5) feed uniformity, (6) solid waste handling, and (7) pollutants emission control. In reviewing these incineration processes, (1) fuel flexibility, (2) environmental acceptability, (3) combustion efficiency, and (4) operational reliability are discussed. The results from a tire incineration experiment conducted at the Morgantown Energy Technology Center are presented in Section 5.0, and a conceptual fluidized-bed combustor is discussed in Section 6.0. Future considerations in the FBC of scrap tires are discussed in Section 7.0. 8 refs., 6 figs., 6 tabs.

  11. Method for immobilizing particulate materials in a packed bed

    DOE Patents [OSTI]

    Even, W.R. Jr.; Guthrie, S.E.; Raber, T.N.; Wally, K.; Whinnery, L.L.; Zifer, T.

    1999-02-02

    The present invention pertains generally to immobilizing particulate matter contained in a packed bed reactor so as to prevent powder migration, compaction, coalescence, or the like. More specifically, this invention relates to a technique for immobilizing particulate materials using a microporous foam-like polymer such that (a) the particulate retains its essential chemical nature, (b) the local movement of the particulate particles is not unduly restricted, (c) bulk powder migration and is prevented, (d) physical and chemical access to the particulate is unchanged over time, and (e) very high particulate densities are achieved. The immobilized bed of the present invention comprises a vessel for holding particulate matter, inlet and an outlet ports or fittings, a loosely packed bed of particulate material contained within the vessel, and a three dimensional porous matrix for surrounding and confining the particles thereby fixing the movement of an individual particle to a limited local position. The established matrix is composed of a series of cells or chambers comprising walls surrounding void space, each wall forming the wall of an adjacent cell; each wall containing many holes penetrating through the wall yielding an overall porous structure and allowing useful levels of gas transport. 4 figs.

  12. Method for immobilizing particulate materials in a packed bed

    DOE Patents [OSTI]

    Even, Jr., William R. (Livermore, CA); Guthrie, Stephen E. (Livermore, CA); Raber, Thomas N. (Livermore, CA); Wally, Karl (Lafayette, CA); Whinnery, LeRoy L. (Livermore, CA); Zifer, Thomas (Manteca, CA)

    1999-01-01

    The present invention pertains generally to immobilizing particulate matter contained in a "packed" bed reactor so as to prevent powder migration, compaction, coalescence, or the like. More specifically, this invention relates to a technique for immobilizing particulate materials using a microporous foam-like polymer such that a) the particulate retains its essential chemical nature, b) the local movement of the particulate particles is not unduly restricted, c) bulk powder migration and is prevented, d) physical and chemical access to the particulate is unchanged over time, and e) very high particulate densities are achieved. The immobilized bed of the present invention comprises a vessel for holding particulate matter, inlet and an outlet ports or fittings, a loosely packed bed of particulate material contained within the vessel, and a three dimensional porous matrix for surrounding and confining the particles thereby fixing the movement of individual particle to a limited local position. The established matrix is composed of a series of cells or chambers comprising walls surrounding void space, each wall forming the wall of an adjacent cell; each wall containing many holes penetrating through the wall yielding an overall porous structure and allowing useful levels of gas transport.

  13. Models and correlations of the DEBRIS Late-Phase Melt Progression Model

    SciTech Connect (OSTI)

    Schmidt, R.C.; Gasser, R.D. [Sandia National Labs., Albuquerque, NM (United States). Reactor Safety Experiments Dept.

    1997-09-01

    The DEBRIS Late Phase Melt Progression Model is an assembly of models, embodied in a computer code, which is designed to treat late-phase melt progression in dry rubble (or debris) regions that can form as a consequence of a severe core uncover accident in a commercial light water nuclear reactor. The approach is fully two-dimensional, and incorporates a porous medium modeling framework together with conservation and constitutive relationships to simulate the time-dependent evolution of such regions as various physical processes act upon the materials. The objective of the code is to accurately model these processes so that the late-phase melt progression that would occur in different hypothetical severe nuclear reactor accidents can be better understood and characterized. In this report the models and correlations incorporated and used within the current version of DEBRIS are described. These include the global conservation equations solved, heat transfer and fission heating models, melting and refreezing models (including material interactions), liquid and solid relocation models, gas flow and pressure field models, and the temperature and compositionally dependent material properties employed. The specific models described here have been used in the experiment design analysis of the Phebus FPT-4 debris-bed fission-product release experiment. An earlier DEBRIS code version was used to analyze the MP-1 and MP-2 late-phase melt progression experiments conducted at Sandia National Laboratories for the US Nuclear Regulatory Commission.

  14. Causes and consequences of sexual selection in a wild population 

    E-Print Network [OSTI]

    Stopher, Katie Vivienne

    2011-11-24

    heterogeneity on selection. Further, important questions remain about the consequences of sexual selection for genetic structuring and genetic variation within populations. In this thesis, I investigate the causes and consequences of sexual selection in a...

  15. Biomechanical consequences of branching in flexible wave-swept macroalgae

    E-Print Network [OSTI]

    Martone, Patrick T.

    Biomechanical consequences of branching in flexible wave-swept macroalgae Samuel Starko1,2 *, Barry Key words: biomechanics, dislodgement, drag, evolution, hydrodynamics, intertidal, macroalgae. Branching has clear biomechanical consequences, increasing drag and the need for increased attachment

  16. Hydraulic fracturing tests in anhydrite interbeds in the WIPP, Marker Beds 139 and 140

    SciTech Connect (OSTI)

    Howard, C L [RE/SPEC Inc., Albuquerque, NM (United States); Wawersik, W. R.; Carlson, L. V.; Henfling, J. A.; Borns, D. J.; Beauheim, R. L.; Roberts, R. M.

    1997-05-01

    Hydraulic fracturing tests were integrated with hydrologic tests to estimate the conditions under which gas pressure in the disposal rooms in the Waste Isolation Pilot Plant, Carlsbad, NM (WIPP) will initiate and advance fracturing in nearby anhydrite interbeds. The measurements were made in two marker beds in the Salado formation, MB139 and MB140, to explore the consequences of existing excavations for the extrapolation of results to undisturbed ground. The interpretation of these measurements is based on the pressure-time records in two injection boreholes and several nearby hydrologic observation holes. Data interpretations were aided by post-test borehole video surveys of fracture traces that were made visible by ultraviolet illumination of fluorescent dye in the hydraulic fracturing fluid. The conclusions of this report relate to the upper- and lower-bound gas pressures in the WIPP, the paths of hydraulically and gas-driven fractures in MB139 and MB140, the stress states in MB139 and MB140, and the probable in situ stress states in these interbeds in undisturbed ground far away from the WIPP.

  17. The Role of the Consequence Management Home Team in the Fukushima Daiichi Response

    SciTech Connect (OSTI)

    Pemberton, W., Mena, R., Beal, W.

    2012-05-01

    The Consequence Management Home Team is a U.S. Department of Energy/National Nuclear Security Administration asset. It assists a variety of response organizations with modeling; radiological operations planning; field monitoring techniques; and the analysis, interpretation, and distribution of radiological data. These reach-back capabilities are activated quickly to support public safety and minimize the social and economic impact of a nuclear or radiological incident. In the Fukushima Daiichi response, the Consequence Management Home Team grew to include a more broad range of support than was historically planned. From the early days of the response to the continuing involvement in supporting late phase efforts, each stage of the Consequence Management Home Team support had distinct characteristics in terms of management of incoming data streams as well as creation of products. Regardless of stage, the Consequence Management Home Team played a critical role in the Fukushima Daiichi response effort.

  18. Experimental study of the hydrodynamics and cluster formation in a Circulating Fluidized Bed

    SciTech Connect (OSTI)

    Gautam, M.; Johnson, E.

    1991-01-01

    A novel non-invasive gas-solid flow measuring technique being developed and tested for studying the hydrodynamics inside the riser of a Circulating Fluidized Bed (CFB). First of the two aims of the overall program, namely, design, development and testing of the technique to characterize the particle and gas velocities in two-phase flows was accomplished in the past year. The fringe-model'' laser Doppler anemometry concept has been modified and extended by using particles coated with a fluorescent dye and introducing a narrow band pass filter in the receiving optics. The technique permits optical discrimination between the scattered light (laser wavelength from undyed particles) and the fluorescence emission (longer wavelength). Results from extensive testing of various dye-solvent combinations, counter processor settings, signal-to noise optimization and subsequent flow measurements in the test section have shown that the technique can effectively discriminate between two classes of particles--the smaller seed particles for the gas phase data and the larger bed particles. Use of a two-watt Argon-Ion laser assisted in the non-intrusive probing of the gas-solid flow and in enhancing the signal-to-noise ratio. An uncertainty analysis of LDA measurements is presented. Design of the cold flow CFB model, presently under fabrication, is outlined in this report. The Plexiglas CFB model will be employed for the riser core-annular flow studies using the fluorescence-emission based laser-Doppler anemometry. The results from this study will present a unique detailed description of the complex gas-solid behavior in the CFB riser.

  19. Epidemiological consequences of an ineffective Bordetella pertussis vaccine

    E-Print Network [OSTI]

    Althouse, Benjamin M

    2014-01-01

    The recent increase in Bordetella pertussis incidence (whooping cough) presents a challenge to global health. Recent studies have called into question the effectiveness of acellular B. pertussis vaccination in reducing transmission. Here we examine the epidemiological consequences of an ineffective B. pertussis vaccine. Using a dynamic transmission model, we find that: 1) an ineffective vaccine can account for the observed increase in B. pertussis incidence; 2) asymptomatic infections can bias surveillance and upset situational awareness of B. pertussis; and 3) vaccinating individuals in close contact with infants too young to receive vaccine (so called "cocooning" unvaccinated children) may be ineffective. Our results have important implications for B. pertussis vaccination policy and paint a complicated picture for achieving herd immunity and possible B. pertussis eradication.

  20. PRECLOSURE CONSEQUENCE ANALYSES FOR LICENSE APPLICATION

    SciTech Connect (OSTI)

    S. Tsai

    2005-01-12

    Radiological consequence analyses are performed for potential releases from normal operations in surface and subsurface facilities and from Category 1 and Category 2 event sequences during the preclosure period. Surface releases from normal repository operations are primarily from radionuclides released from opening a transportation cask during dry transfer operations of spent nuclear fuel (SNF) in Dry Transfer Facility 1 (DTF 1), Dry Transfer Facility 2 (DTF 2), the Canister Handling facility (CHF), or the Fuel Handling Facility (FHF). Subsurface releases from normal repository operations are from resuspension of waste package surface contamination and neutron activation of ventilated air and silica dust from host rock in the emplacement drifts. The purpose of this calculation is to demonstrate that the preclosure performance objectives, specified in 10 CFR 63.111(a) and 10 CFR 63.111(b), have been met for the proposed design and operations in the geologic repository operations area. Preclosure performance objectives are discussed in Section 6.2.3 and are summarized in Tables 1 and 2.

  1. Phase 2 Methyl Iodide Deep-Bed Adsorption Tests

    SciTech Connect (OSTI)

    Soelberg, Nick; Watson, Tony

    2014-09-01

    Nuclear fission produces fission products (FPs) and activation products, including iodine-129, which could evolve into used fuel reprocessing facility off-gas systems, and could require off-gas control to limit air emissions to levels within acceptable emission limits. Research, demonstrations, and some reprocessing plant experience have indicated that diatomic iodine can be captured with efficiencies high enough to meet regulatory requirements. Research on the capture of organic iodides has also been performed, but to a lesser extent. Several questions remain open regarding the capture of iodine bound in organic compounds. Deep-bed methyl iodide adsorption testing has progressed according to a multi-laboratory methyl iodide adsorption test plan. This report summarizes the second phase of methyl iodide adsorption work performed according to this test plan using the deep-bed iodine adsorption test system at the Idaho National Laboratory (INL), performed during the second half of Fiscal Year (FY) 2014. Test results continue to show that methyl iodide adsorption using AgZ can achieve total iodine decontamination factors (DFs, ratios of uncontrolled and controlled total iodine levels) above 1,000, until breakthrough occurred. However, mass transfer zone depths are deeper for methyl iodide adsorption compared to diatomic iodine (I2) adsorption. Methyl iodide DFs for the Ag Aerogel test adsorption efficiencies were less than 1,000, and the methyl iodide mass transfer zone depth exceeded 8 inches. Additional deep-bed testing and analyses are recommended to (a) expand the data base for methyl iodide adsorption under various conditions specified in the methyl iodide test plan, and (b) provide more data for evaluating organic iodide reactions and reaction byproducts for different potential adsorption conditions.

  2. CERTS Microgrid Laboratory Test Bed - PIER Final Project Report

    SciTech Connect (OSTI)

    Eto, Joseph H.; Eto, Joseph H.; Lasseter, Robert; Schenkman, Ben; Klapp, Dave; Linton, Ed; Hurtado, Hector; Roy, Jean; Lewis, Nancy Jo; Stevens, John; Volkommer, Harry

    2008-07-25

    The objective of the CERTS Microgrid Laboratory Test Bed project was to enhance the ease of integrating small energy sources into a microgrid. The project accomplished this objective by developing and demonstrating three advanced techniques, collectively referred to as the CERTS Microgrid concept, that significantly reduce the level of custom field engineering needed to operate microgrids consisting of small generating sources. The techniques comprising the CERTS Microgrid concept are: 1) a method for effecting automatic and seamless transitions between grid-connected and islanded modes of operation; 2) an approach to electrical protection within the microgrid that does not depend on high fault currents; and 3) a method for microgrid control that achieves voltage and frequency stability under islanded conditions without requiring high-speed communications. The techniques were demonstrated at a full-scale test bed built near Columbus, Ohio and operated by American Electric Power. The testing fully confirmed earlier research that had been conducted initially through analytical simulations, then through laboratory emulations, and finally through factory acceptance testing of individual microgrid components. The islanding and resychronization method met all Institute of Electrical and Electronics Engineers 1547 and power quality requirements. The electrical protections system was able to distinguish between normal and faulted operation. The controls were found to be robust and under all conditions, including difficult motor starts. The results from these test are expected to lead to additional testing of enhancements to the basic techniques at the test bed to improve the business case for microgrid technologies, as well to field demonstrations involving microgrids that involve one or mroe of the CERTS Microgrid concepts.

  3. Characterization of bedded salt for storage caverns -- A case study from the Midland Basin, Texas

    SciTech Connect (OSTI)

    Hovorka, Susan D.; Nava, Robin

    2000-06-13

    The geometry of Permian bedding salt in the Midland Basin is a product of interaction between depositional facies and postdepositional modification by salt dissolution. Mapping high-frequency cycle patterns in cross section and map view using wireline logs documents the salt geometry. Geologically based interpretation of depositional and dissolution processes provides a powerful tool for mapping and geometry of salt to assess the suitability of sites for development of solution-mined storage caverns. In addition, this process-based description of salt geometry complements existing data about the evolution of one of the best-known sedimentary basins in the world, and can serve as a genetic model to assist in interpreting other salts.

  4. Continuous Ethanol Production Using Immobilized-Cell/Enzyme Biocatalysts in Fluidized-Bed Bioreactor (FBR)

    SciTech Connect (OSTI)

    Nghiem, NP

    2003-11-16

    The immobilized-cell fluidized-bed bioreactor (FBR) was developed at Oak Ridge National Laboratory (ORNL). Previous studies at ORNL using immobilized Zymomonas mobilis in FBR at both laboratory and demonstration scale (4-in-ID by 20-ft-tall) have shown that the system was more than 50 times as productive as industrial benchmarks (batch and fed-batch free cell fermentations for ethanol production from glucose). Economic analysis showed that a continuous process employing the FBR technology to produce ethanol from corn-derived glucose would offer savings of three to six cents per gallon of ethanol compared to a typical batch process. The application of the FBR technology for ethanol production was extended to investigate more complex feedstocks, which included starch and lignocellulosic-derived mixed sugars. Economic analysis and mathematical modeling of the reactor were included in the investigation. This report summarizes the results of these extensive studies.

  5. Neutron-antineutron transition as a test-bed for dynamical CPT violations

    E-Print Network [OSTI]

    Andrea Addazi

    2015-08-30

    We show a simple mechanism for a dynamical CPT violation in the neutron sector. In particular, we show a {\\it CPT-violating see-saw mechanism}, generating a Majorana mass and a CPT violating mass for the neutron. CPT-violating see-saw involves a sterile partner of the neutron, living in a hidden sector, in which CPT is spontaneously broken. In particular, neutrons (antineutrons) can communicate with the hidden sector through non-perturbative quantum gravity effects called {\\it exotic instantons}. Exotic instantons dynamically break R-parity, generating one effective vertex between the neutron and its sterile partner. In this way, we show how a small CPT violating mass term for the neutron is naturally generated. This model can be tested in the next generation of experiments in neutron-antineutron physics. This strongly motivates researches of CPT-violating effects in neutron-antineutron physics, as a test-bed for dynamical CPT-violations in SM.

  6. Packed bed carburization of tantalum and tantalum alloy

    DOE Patents [OSTI]

    Lopez, Peter C. (Espanola, NM); Rodriguez, Patrick J. (Espanola, NM); Pereyra, Ramiro A. (Medanales, NM)

    1999-01-01

    Packed bed carburization of a tantalum or tantalum alloy object. A method for producing corrosion-resistant tantalum or tantalum alloy objects is described. The method includes the steps of placing the object in contact with a carburizing pack, heating the packed object in vacuum furnace to a temperature whereby carbon from the pack diffuses into the object forming grains with tantalum carbide along the grain boundaries, and etching the surface of the carburized object. This latter step removes tantalum carbides from the surface of the carburized tantalum object while leaving the tantalum carbide along the grain boundaries.

  7. Metrics for the National SCADA Test Bed Program

    SciTech Connect (OSTI)

    Craig, Philip A.; Mortensen, J.; Dagle, Jeffery E.

    2008-12-05

    The U.S. Department of Energy Office of Electricity Delivery and Energy Reliability (DOE-OE) National SCADA Test Bed (NSTB) Program is providing valuable inputs into the electric industry by performing topical research and development (R&D) to secure next generation and legacy control systems. In addition, the program conducts vulnerability and risk analysis, develops tools, and performs industry liaison, outreach and awareness activities. These activities will enhance the secure and reliable delivery of energy for the United States. This report will describe metrics that could be utilized to provide feedback to help enhance the effectiveness of the NSTB Program.

  8. Dynamical Simulation of Fluidized Beds --- Hydrodynamically Interacting Granular Particles

    E-Print Network [OSTI]

    Kengo Ichiki; Hisao Hayakawa

    1995-03-01

    A numerical simulation of a gas-fluidized bed is performed without introduction of any empirical parameters. Realistic bubbles and slugs are observed in our simulation. It is found that the convective motion of particles is important for the bubbling phase and there is no convection in the slugging phase. From the simulation results, non-Gaussian distributions are found in the particle velocities and the relation between the deviation from Gaussian and the local density of particles is suggested. It is also shown that the power spectra of particle velocities obey power laws. A brief explanation on the relationship between the simulation results and the Kolmogorov scaling argument is discussed.

  9. Combustion of Cattle Manure in a Fluidized Bed Combustor 

    E-Print Network [OSTI]

    Annamalai, K.; Colaluca, M. A.; Ibrahim, M. Y.; Sweeten, J. M.

    1988-01-01

    from -ZO to +ZO percent while keeping bed temperature constant at 650 0 e (lZ00?F) and u/u mf - 1.5. The concentrations of eo z , eo, eH 4 , e H , and e H Z 4 3 6 diminished with the increase in percentage of excess air (Figure 4). Even though... there is increased production of eo due to oxidation of Z eo, eH 4 , etc., the air dilution effect had a tendency to reduce eo Z concentration. The eo and hydrocarbons appear to have decreased with more excess air. Similar results were observed and Madan [la...

  10. Packed bed carburization of tantalum and tantalum alloy

    DOE Patents [OSTI]

    Lopez, P.C.; Rodriguez, P.J.; Pereyra, R.A.

    1999-06-29

    Packed bed carburization of a tantalum or tantalum alloy object is disclosed. A method for producing corrosion-resistant tantalum or tantalum alloy objects is described. The method includes the steps of placing the object in contact with a carburizing pack, heating the packed object in vacuum furnace to a temperature whereby carbon from the pack diffuses into the object forming grains with tantalum carbide along the grain boundaries, and etching the surface of the carburized object. This latter step removes tantalum carbides from the surface of the carburized tantalum object while leaving the tantalum carbide along the grain boundaries. 4 figs.

  11. Hydraulically refueled battery employing a packed bed metal particle electrode

    DOE Patents [OSTI]

    Siu, S.C.; Evans, J.W.

    1998-12-15

    A secondary zinc air cell, or another selected metal air cell, employing a spouted/packed metal particle bed and an air electrode is described. More specifically, two embodiments of a cell, one that is capable of being hydraulically recharged, and a second that is capable of being either hydraulically or electrically recharged. Additionally, each cell includes a sloped bottom portion to cause stirring of the electrolyte/metal particulate slurry when the cell is being hydraulically emptied and refilled during hydraulically recharging of the cell. 15 figs.

  12. Standby cooling system for a fluidized bed boiler

    DOE Patents [OSTI]

    Crispin, Larry G. (Akron, OH); Weitzel, Paul S. (Canal Fulton, OH)

    1990-01-01

    A system for protecting components including the heat exchangers of a fluidized bed boiler against thermal mismatch. The system includes an injection tank containing an emergency supply of heated and pressurized feedwater. A heater is associated with the injection tank to maintain the temperature of the feedwater in the tank at or about the same temperature as that of the feedwater in the heat exchangers. A pressurized gas is supplied to the injection tank to cause feedwater to flow from the injection tank to the heat exchangers during thermal mismatch.

  13. Craters Formed in Granular Beds by Impinging Jets of Gas

    E-Print Network [OSTI]

    Philip T. Metzger; Robert C. Latta III; Jason M. Schuler; Christopher D. Immer

    2009-05-29

    When a jet of gas impinges vertically on a granular bed and forms a crater, the grains may be moved by several different mechanisms: viscous erosion, diffused gas eruption, bearing capacity failure, and/or diffusion-driven shearing. The relative importance of these mechanisms depends upon the flow regime of the gas, the mechanical state of the granular material, and other physical parameters. Here we report research in two specific regimes: viscous erosion forming scour holes as a function of particle size and gravity; and bearing capacity failure forming deep transient craters as a function of soil compaction.

  14. Fluidized-bed bioreactor process for the microbial solubiliztion of coal

    DOE Patents [OSTI]

    Scott, Charles D. (Oak Ridge, TN); Strandberg, Gerald W. (Farragut, TN)

    1989-01-01

    A fluidized-bed bioreactor system for the conversion of coal into microbially solubilized coal products. The fluidized-bed bioreactor continuously or periodically receives coal and bio-reactants and provides for the production of microbially solubilized coal products in an economical and efficient manner. An oxidation pretreatment process for rendering coal uniformly and more readily susceptible to microbial solubilization may be employed with the fluidized-bed bioreactor.

  15. Fluidized-bed bioreactor system for the microbial solubilization of coal

    DOE Patents [OSTI]

    Scott, C.D.; Strandberg, G.W.

    1987-09-14

    A fluidized-bed bioreactor system for the conversion of coal into microbially solubilized coal products. The fluidized-bed bioreactor continuously or periodically receives coal and bio-reactants and provides for the production of microbially solubilized coal products in an economical and efficient manner. An oxidation pretreatment process for rendering coal uniformly and more readily susceptible to microbial solubilization may be employed with the fluidized-bed bioreactor. 2 figs.

  16. Fixed-bed bioreactor system for the microbial solubilization of coal

    DOE Patents [OSTI]

    Scott, C.D.; Strandberg, G.W.

    1987-09-14

    A fixed-bed bioreactor system for the conversion of coal into microbially solubilized coal products. The fixed-bed bioreactor continuously or periodically receives coal and bio-reactants and provides for the large scale production of microbially solubilized coal products in an economical and efficient manner. An oxidation pretreatment process for rendering coal uniformly and more readily susceptible to microbial solubilization may be employed with the fixed-bed bioreactor. 1 fig., 1 tab.

  17. Reduction of FeO contents in sinter under high bed operation

    SciTech Connect (OSTI)

    Fujii, K.; Hazama, K.; Hoshikuma, Y.; Tarumoto, S.; Nunomura, S.; Hirota, N.

    1996-12-31

    High-bed operation (bed height more than 700 mm) is currently being carried out at the Kure No. 1 sintering plant. Before initiating this high-bed operation, the authors conducted sinter pot tests at various bed heights to investigate the effect of bed height on sintering. The following results were obtained from these pot tests: Heightening of the sinter bed increased yield at the upper layer, but at the lower layer, the yield reached a maximum value at a certain bed height. From observation of the sinter cakes, the reduction in yield is attributed to uneven burn caused by surplus heat at the lower layers. Therefore, when high-bed operation is carried out, reduction of the burning energy (reduction of the FeO content in the sinter) is required. This high-bed operation with lower FeO content has enabled the company to reduce fuel consumption and SiO{sub 2} content, while maintaining high yield and high sinter quality.

  18. 100 Hour test of the pressurized woodchip-fired gravel bed combustor

    SciTech Connect (OSTI)

    Ragland, K.W.; Aerts, D.J.

    1994-08-01

    Combustion of wood chips in a packed bed combustor for a gas turbine cogeneration system is described. A discussion on flue gas emissions and mass balances is included.

  19. Fixed bed trapping for gaseous fluoride effluent control

    SciTech Connect (OSTI)

    Otey, M.G.; Bayne, C.K.

    1980-06-14

    To comply with future air quality standards for gaseous fluoride emissions at the PGDP, studies are being made to evaluate the most feasible and efficient method of trapping fluorides from the effluents of the different processes. Although this work is in direct support of environmental projects, its results are applicable in other areas. Throughout the diffusion plants there are several areas where fluorides, either single or multiple species, are controlled and/or processed. The solid sorbent studies represent new, promising technology which could have significant impact on the gaseous diffusion plants. Scoping studies of solid sorbents and reaction conditions have been conducted. In a series of statistically designed experiments, the effects of total gas flow, temperature, and fluoride gas flow were studied for eight dry chemicals in a 1-in. diameter fixed bed designed to remove three separate fluoride gas species (hydrogen fluoride (HF), fluorine (F/sub 2/), and chlorine trifluoride (ClF/sub 3/)) from an air stream. The trapping materials selected for the test include two brands of four different material types: soda lime, oolitic calcium carbonate (CaCO/sub 3/), calcium oxide (CaO), and activated alumina (Al/sub 2/O/sub 3/). Additionally, loading factors and material utilization were determined to allow an economic comparison to be made between bed materials.

  20. Zevenhoven & Kilpinen NITROGEN 13.4.2002 4-34 4.11 Chemistry of nitrogen oxides at atmospheric fluidized bed

    E-Print Network [OSTI]

    Laughlin, Robert B.

    : - Bubbling fluidized bed combustion (BFBC) is a combustion method where the velocity of the gasflow upwards fluidized bed combustion, where the interaction between gas and particles is more intensive than in bubbling fluidized bed combustion In fluidized bed combustion, the combustion takes place in a bed of particles

  1. THE STATE OF THE ART OF NUMERICAL MODELING OF THERMOHYDROLOGIC FLOW IN FRACTURED ROCK MASSES

    E-Print Network [OSTI]

    Wang, J.S.Y.

    2013-01-01

    thermal calculations for the WIPP site in southeastern NewWaste Isolation Pilot Plant (WIPP) in bedded salt. The codepersonal communication 1980). WIPP The modeling for WIPP is

  2. Final Report on Utilization of TRU TRISO Fuel as Applied to HTR Systems Part I: Pebble Bed Reactors

    SciTech Connect (OSTI)

    Brian Boer; Abderrafi M. Ougouag

    2011-03-01

    The Deep-Burn (DB) concept [ ] focuses on the destruction of transuranic nuclides from used light water reactor (LWR) fuel. These transuranic nuclides are incorporated into tri-isotopic (TRISO) coated fuel particles and used in gas-cooled reactors with the aim of a fractional fuel burnup of 60 to 70% in fissions per initial metal atom (FIMA). This high performance is expected through the use of multiple recirculation passes of the fuel in pebble form without any physical or chemical changes between passes. In particular, the concept does not call for reprocessing of the fuel between passes. In principle, the DB pebble bed concept employs the same reactor designs as the presently envisioned low-enriched uranium core designs, such as the 400 MWth Pebble Bed Modular Reactor (PBMR-400) [ ]. Although it has been shown in the previous Fiscal Year (FY) (2009) that a PuO2 fueled pebble bed reactor concept is viable, achieving a high fuel burnup while remaining within safety-imposed prescribed operational limits for fuel temperature, power peaking, and temperature reactivity feedback coefficients for the entire temperature range, is challenging. The presence of the isotopes 239Pu, 240Pu, and 241Pu that have resonances in the thermal energy range significantly modifies the neutron thermal energy spectrum as compared to a standard, UO2-fueled core. Therefore, the DB pebble bed core exhibits a relatively hard neutron energy spectrum. However, regions within the pebble bed that are near the graphite reflectors experience a locally softer spectrum. This can lead to power and temperature peaking in these regions. Furthermore, a shift of the thermal energy spectrum with increasing temperature can lead to increased absorption in the resonances of the fissile Pu isotopes. This can lead to a positive temperature reactivity coefficient for the graphite moderator under certain operating conditions. Regarding the coated particle performance, the FY 2009 investigations showed that no significant failure is to be expected for the reference fuel particle during normal operation. It was found, however, that the sensitivity of the coating stress to the CO production in the kernel was large. The CO production is expected to be higher in DB fuel than in UO2 fuel, but its exact level has a high uncertainty. Furthermore, in the fuel performance analysis transient conditions were not yet taken into account. The effort of this task in FY 2010 has focused on the optimization of the core to maximize the pebble discharge burnup level, while retaining its inherent safety characteristics. Using generic pebble bed reactor cores, this task will perform physics calculations to evaluate the capabilities of the pebble bed reactor to perform utilization and destruction of LWR used-fuel transuranics. The task will use established benchmarked models, and will introduce modeling advancements appropriate to the nature of the fuel considered (high transuranic [TRU] content and high burn-up). Accomplishments of this work include: •Core analysis of a HTR-MODULE design loaded with Deep-Burn fuel. •Core analysis of a HTR-MODULE design loaded with Deep-Burn fuel and Uranium. •Core analysis of a HTR-MODULE design loaded with Deep-Burn fuel and Modified Open Cycle Components. •Core analysis of a HTR-MODULE design loaded with Deep-Burn fuel and Americium targets.

  3. Vacuum Energy Sequestering: The Framework and Its Cosmological Consequences

    E-Print Network [OSTI]

    Nemanja Kaloper; Antonio Padilla

    2014-10-30

    Recently we suggested a reformulation of General Relativity which completely sequesters from gravity {\\it all} of the vacuum energy from a protected matter sector, assumed to contain the Standard Model. Here we elaborate further on the mechanism, presenting additional details of how it cancels all loop corrections and renders all contributions from phase transitions automatically small. We also consider cosmological consequences in more detail and show that the mechanism is consistent with a variety of inflationary models that make a universe big and old. We discuss in detail the underlying assumptions behind the dynamics of our proposal, and elaborate on the relationship of the physical interpretation of divergent operators in quantum field theory and the apparent `acausality' which our mechanism seems to entail, which we argue is completely harmless. It is merely a reflection of the fact that any UV sensitive quantity in quantum field theory cannot be calculated from first principles, but is an input whose numerical value must be measured. We also note that since the universe should be compact in spacetime, and so will collapse in the future, the current phase of acceleration with $w_{DE}\\approx-1$ is just a transient. This could be tested by future cosmological observations.

  4. Jet Induced Supernovae-Hydrodynamics and Observational Consequences

    E-Print Network [OSTI]

    A. Khokhlov; Peter Hoeflich

    2000-11-01

    Core collapse supernovae (SN) are the final stages of stellar evolution in massive stars during which the central region collapses, forms a neutron star (NS), and the outer layers are ejected. Recent explosion scenarios assumed that the ejection is due to energy deposition by neutrinos into the envelope but detailed models do not produce powerful explosions. There is mounting evidence for an asphericity in the SN which is difficult to explain within this picture. This evidence includes the observed high polarization, pulsar kicks, high velocity iron-group and intermediate-mass elements material observed in remnants, etc. The discovery of highly magnetars revived the idea that the basic mechanism for the ejection of the envelope is related to a highly focused MHD-jet formed at the NS. Our 3-D hydro simulations of the jet propagation through the star confirmed that the mechanism can explain the asphericities. In this paper, detailed 3-D models for jet induced explosions of "classical" core collapse supernovae are presented. We demonstrate the influence of the jet properties and of the underlaying progenitor structure on the final density and chemical structure. Finally, we discuss the observational consequences, predictions and tests of this scenario.

  5. Federalism in Europe and Latin America: Conceptualization, Causes, and Consequences

    E-Print Network [OSTI]

    Eaton, Kent

    2008-01-01

    AMERICA Conceptualization, Causes, and Consequences By KENTCayeros investigates the causes of ?scal centralization insecond section turns to the causes of federalism, a question

  6. Reforestation: Bedding for Site Preparation http://tfsweb.tamu.edu Page 1 of 1

    E-Print Network [OSTI]

    preparation methods such as 3 in 1 plowing or ripping. Following the planting operation, it is usually from the planting site. Water outlets should be provided at locations that will minimize soil movementReforestation: Bedding for Site Preparation http://tfsweb.tamu.edu Page 1 of 1 Benefits: Bedding

  7. Annual Logging Symposium, June 3-6, 2007 QUANTITATIVE STUDIES OF RELATIVE DIP ANGLE AND BED -

    E-Print Network [OSTI]

    Torres-Verdín, Carlos

    AND BED - THICKNESS EFFECTS ON LWD DENSITY IMAGES ACQUIRED IN HIGH-ANGLE AND HORIZONTAL WELLS E.A. Uzoh, A (LWD) density images acquired in high-angle and horizontal (HA/HZ) wells can reveal much about to quantify the influence of relative dip angle and bed thickness on LWD density images acquired in HA

  8. Bedding and Within-Pen Location Effects on Feedlot Pen Runoff Quality Using a Rainfall Simulator

    E-Print Network [OSTI]

    Selinger, Brent

    of feedlots are using wood-chip bedding (Miller et al., 2003). Wood chips tend to have a higher carbon content than wood-chip bedding. They also found higher total carbon, carbon to nitrogen ratios, NH4­N, and available P in manure with wood-chip beddin

  9. Design, Analysis and Optimization of the Power Conversion System for the Modular Pebble Bed Reactor System

    E-Print Network [OSTI]

    Design, Analysis and Optimization of the Power Conversion System for the Modular Pebble Bed Reactor August 31, 2003 Certified by Ronald G. Ballinger Professor of Nuclear Engineering and Materials Science;2 #12;Design, Analysis, and Optimization of the Power Conversion System for the Modular Pebble Bed

  10. Foam Control using a Fluidized Bed of Hydrophobic Particles by Clara Mata*

    E-Print Network [OSTI]

    Joseph, Daniel D.

    Foam Control using a Fluidized Bed of Hydrophobic Particles by Clara Mata* & D. D. Joseph may be strongly suppressed by fluidizing hydrophilic particles in the bubbly mixture below the foam different tests (particle-induced film rupture and foam shake test), but they did not use a fluidized bed

  11. Using the depth-velocity-size diagram to interpret equilibrium bed configurations in river flows

    SciTech Connect (OSTI)

    Southard, J.B. (Massachusetts Institute of Technology, Cambridge, MA (USA))

    1990-05-01

    Data from flume studies that report equilibrium bed configuration as well as water temperature, flow depth, flow velocity, and sediment size were used to develop the best approximation to the relationships among the various bed phases (ripples, dunes, lower regime plane bed, upper regime plane bed, and antidunes) in a three-axis graph (depth-velocity-size diagram) with dimensionless measures of mean flow depth, mean flow velocity, and sediment size along the axis. Relationships are shown in a series of depth-velocity and velocity-size sections through the diagram. Boundaries between bed-phase stability fields are drawn as surfaces that minimize, misplacement of data points. A large subset of the data, for which reliable values of bed shear stress are reported, was also used to represent the stability relationships in a graph of dimensionless boundary shear stress against dimensionless sediment size, but with results less useful for fluvial flow interpretation. The diagram covers about one order of magnitude in flow depth. To be useful for river flows, the diagram must be extrapolated in flow depth by about one more order of magnitude, but this is not a serious problem for approximate work. The depth-velocity-size diagram permits prediction of equilibrium bed configuration in river flows when the approximate flow depth and mean flow velocity are known. Because the diagram is essentially dimensionless, the effect of water temperature (via the fluid viscosity) on the bed configuration is easily accounted for by use of the diagram.

  12. Effects of sediment pulses on bed relief in bar-pool John P. P. Zunka,1

    E-Print Network [OSTI]

    Tullos, Desiree

    Effects of sediment pulses on bed relief in bar-pool channels John P. P. Zunka,1 * Desiree D associated with sediment pulses in bar- pool channels, we analyze channel bed topographic data collected relief to sand and gravel sediment pulses is a function of initial relief and pulse magnitude. Modest

  13. Pulsed atmospheric fluidized bed combustion. Technical progress report, April 1992--June 1992

    SciTech Connect (OSTI)

    Not Available

    1992-08-01

    The general specifications for a Pulsed Atmospheric Fluidized Bed Combustor Design Report (PAFBC) plant are presented. The design tasks for the PAFBC are described in the following areas: Coal/Limestone preparation and feed system; pulse combustor; fluidized bed; boiler parts; and ash handling system.

  14. Effects of hydraulic roughness on surface textures of gravel-bed rivers

    E-Print Network [OSTI]

    Montgomery, David R.

    Effects of hydraulic roughness on surface textures of gravel-bed rivers John M. Buffington1 that bed-surface grain size is responsive to hydraulic roughness caused by bank irregularities, bars condition of low hydraulic roughness. For a given 0bf , channels with progressively greater hydraulic

  15. Role of Fungi in Postfire Stabilization of Chaparral Ash Beds1

    E-Print Network [OSTI]

    Role of Fungi in Postfire Stabilization of Chaparral Ash Beds1 Paul H. Dunn, Wade G. Wells II characteristic of thermo- philes. The heat-shock fungi in ash beds are adapted to the high ammonium and pH conditions of the ash and are capable of very rapid growth rates. They are, however, unable to compete

  16. Effect of Sand Supply on Transport Rates in a Gravel-Bed Channel

    E-Print Network [OSTI]

    Curran, Joanna C.

    Effect of Sand Supply on Transport Rates in a Gravel-Bed Channel Joanna C. Curran, A.M.ASCE,1 depth, and gravel feed rate, sand feed rates were varied from 0.16 to 6.1 times that of gravel. The bed slope decreased with increasing sand supply, indicating that the gravel could be transported at the same

  17. REAL-TIME BUILDING ENERGY SIMULATION USING ENERGYPLUS AND THE BUILDING CONTROLS VIRTUAL TEST BED

    E-Print Network [OSTI]

    REAL-TIME BUILDING ENERGY SIMULATION USING ENERGYPLUS AND THE BUILDING CONTROLS VIRTUAL TEST BED as simulated of EnergyPlus. The Building Control Virtual Test Bed (BCVTB) is used as the software platform. INTRODUCTION EnergyPlus (US DOE, 2010; Crawley et al., 2001) is a detailed first principles based simulation

  18. Operation of a steam hydro-gasifier in a fluidized bed reactor

    E-Print Network [OSTI]

    Park, Chan Seung; Norbeck, Joseph N.

    2008-01-01

    OF A S T E A M HYDRO-GASIFIER IN A FLUIDIZED BED REACTOROF A S T E A M HYDRO-GASIFIER IN A FLUIDIZED BED REACTOR F Iis fed into a hydro-gasifier reactor. One such process was

  19. EFFECTIVE THERMAL CONDUCTIVITY OF LITHIUM CERAMIC PEBBLE BEDS FOR FUSION BLANKETS: A REVIEW

    E-Print Network [OSTI]

    Abdou, Mohamed

    EFFECTIVE THERMAL CONDUCTIVITY OF LITHIUM CERAMIC PEBBLE BEDS FOR FUSION BLANKETS: A REVIEW A. ABOU-1597, ali@fusion.ucla.edu The use of lithium ceramic pebble beds has been considered in many blanket designs for the fusion reactors. Lithium ceramics have received a significant interest as tritium breeders for the fusion

  20. A review of research and methods for producing high-consequence software

    SciTech Connect (OSTI)

    Collins, E.; Dalton, L.; Peercy, D.; Pollock, G.; Sicking, C.

    1994-12-31

    The development of software for use in high-consequence systems mandates rigorous (formal) processes, methods, and techniques to improve the safety characteristics of those systems. This paper provides a brief overview of current research and practices in high-consequence software, including applied design methods. Some of the practices that are discussed include: fault tree analysis, failure mode effects analysis, petri nets, both hardware and software interlocks, n-version programming, Independent Vulnerability Analyses, and watchdogs. Techniques that offer improvement in the dependability of software in high-consequence systems applications are identified and discussed. Limitations of these techniques are also explored. Research in formal methods, the cleanroom process, and reliability models are reviewed. In addition, current work by several leading researchers as well as approaches being used by leading practitioners are examined.

  1. Continuous fluidized-bed contactor with recycle of sorbent

    DOE Patents [OSTI]

    Scott, Charles D. (Oak Ridge, TN); Petersen, James N. (Moscow, ID); Davison, Brian H. (Knoxville, TN)

    1996-01-01

    A continuous fluidized-bed contactor containing sorbent particles is used to remove solutes from liquid solvents. As the sorbent particles, for example gel beads, sorb the solute, for example metal ion species, the sorbent particles tend to decrease in diameter. These smaller loaded sorbent particles rise to the top of the contactor, as larger sorbent particles remain at the bottom of the contactor as a result of normal hydraulic forces. The smaller loaded sorbent particles are then recovered, regenerated, and reintroduced into the contactor. Alternatively, the loaded sorbent particles may also slightly increase in diameter, or exhibit no change in diameter but an increase in density. As a result of normal hydraulic forces the larger loaded sorbent particles fall to the bottom of the contactor. The larger loaded sorbent particles are then recovered, regenerated, and reintroduced into the contactor.

  2. Down-flow moving-bed gasifier with catalyst recycle

    DOE Patents [OSTI]

    Halow, J.S.

    1999-04-20

    The gasification of coal and other carbonaceous materials by an endothermic gasification reaction is achieved in the presence of a catalyst in a down-flow, moving-bed gasifier. Catalyst is removed along with ash from the gasifier and is then sufficiently heated in a riser/burner by the combustion of residual carbon in the ash to volatilize the catalyst. This volatilized catalyst is returned to the gasifier where it uniformly contacts and condenses on the carbonaceous material. Also, the hot gaseous combustion products resulting from the combustion of the carbon in the ash along with excess air are introduced into the gasifier for providing heat energy used in the endothermic reaction. 1 fig.

  3. Down-flow moving-bed gasifier with catalyst recycle

    DOE Patents [OSTI]

    Halow, John S. (Waynesburg, PA)

    1999-01-01

    The gasification of coal and other carbonaceous materials by an endothermic gasification reaction is achieved in the presence of a catalyst in a down-flow, moving-bed gasifier. Catalyst is removed along with ash from the gasifier and is then sufficiently heated in a riser/burner by the combustion of residual carbon in the ash to volatilize the catalyst. This volatilized catalyst is returned to the gasifier where it uniformly contacts and condenses on the carbonaceous material. Also, the hot gaseous combustion products resulting from the combustion of the carbon in the ash along with excess air are introduced into the gasifier for providing heat energy used in the endothermic reaction.

  4. Continuous fluidized-bed contactor with recycle of sorbent

    DOE Patents [OSTI]

    Scott, C.D.; Petersen, J.N.; Davison, B.H.

    1996-07-09

    A continuous fluidized-bed contactor containing sorbent particles is used to remove solutes from liquid solvents. As the sorbent particles, for example gel beads, sorb the solute, for example metal ion species, the sorbent particles tend to decrease in diameter. These smaller loaded sorbent particles rise to the top of the contactor, and larger sorbent particles remain at the bottom of the contactor as a result of normal hydraulic forces. The smaller loaded sorbent particles are then recovered, regenerated, and reintroduced into the contactor. Alternatively, the loaded sorbent particles may also slightly increase in diameter, or exhibit no change in diameter but an increase in density. As a result of normal hydraulic forces the larger loaded sorbent particles fall to the bottom of the contactor. The larger loaded sorbent particles are then recovered, regenerated, and reintroduced into the contactor. 8 figs.

  5. Hydrological consequences of Eucalyptus afforestation in the Argentine Pampas

    E-Print Network [OSTI]

    Jackson, Robert B.

    Hydrological consequences of Eucalyptus afforestation in the Argentine Pampas Vic Engel,1 Esteban G of Eucalyptus camaldulensis in the Pampas grasslands of Argentina were explored for 2 years using a novel. B. Jackson (2005), Hydrological consequences of Eucalyptus afforestation in the Argentine Pampas

  6. Durability Testing of Fluidized Bed Steam Reforming Products

    SciTech Connect (OSTI)

    JANTZEN, CAROL M.; PAREIZS, JOHN M.; LORIER, TROY H.; MARRA, JAMES C.

    2005-07-01

    Fluidized Bed Steam Reforming (FBSR) is being considered as a potential technology for the immobilization of a wide variety of radioactive wastes but especially aqueous high sodium wastes at the Hanford site, at the Idaho National Laboratory (INL), and at the Savannah River Site (SRS). The FBSR technology converts organic compounds to CO{sub 2} and H{sub 2}O, converts nitrate/nitrite species to N{sub 2}, and produces a solid residue through reactions with superheated steam, the fluidizing media. If clay is added during processing a ''mineralized'' granular waste form can be produced. The mineral components of the waste form are primarily Na-Al-Si (NAS) feldspathoid minerals with cage-like and ring structures and iron bearing spinel minerals. The cage and ring structured minerals atomically bond radionuclides like Tc{sup 99} and Cs{sup 137} and anions such as SO{sub 4}, I, F, and Cl. The spinel minerals appear to stabilize Resource Conservation and Recovery Act (RCRA) hazardous species such as Cr and Ni. Durability testing of the FBSR products was performed using ASTM C1285 (Product Consistency Test) and the Environmental Protection Agency (EPA) Toxic Characteristic Leaching Procedure (TCLP). The FBSR mineral products (bed and fines) evaluated in this study were found to be two orders of magnitude more durable than the Hanford Low Activity Waste (LAW) glass requirement of 2 g/m{sup 2} release of Na{sup +}. The PCT responses for the FBSR samples tested were consistent with results from previous FBSR Hanford LAW product testing. Differences in the response can be explained by the minerals formed and their effects on PCT leachate chemistry.

  7. Enhanced Coal Bed Methane Recovery and CO2 Sequestration in the Powder River Basin

    SciTech Connect (OSTI)

    Eric P. Robertson

    2010-06-01

    Unminable coal beds are potentially large storage reservoirs for the sequestration of anthropogenic CO2 and offer the benefit of enhanced methane production, which can offset some of the costs associated with CO2 sequestration. The objective of this report is to provide a final topical report on enhanced coal bed methane recovery and CO2 sequestration to the U.S. Department of Energy in fulfillment of a Big Sky Carbon Sequestration Partnership milestone. This report summarizes work done at Idaho National Laboratory in support of Phase II of the Big Sky Carbon Sequestration Partnership. Research that elucidates the interaction of CO2 and coal is discussed with work centering on the Powder River Basin of Wyoming and Montana. Sorption-induced strain, also referred to as coal swelling/shrinkage, was investigated. A new method of obtaining sorption-induced strain was developed that greatly decreases the time necessary for data collection and increases the reliability of the strain data. As coal permeability is a strong function of sorption-induced strain, common permeability models were used to fit measured permeability data, but were found inadequate. A new permeability model was developed that can be directly applied to coal permeability data obtained under laboratory stress conditions, which are different than field stress conditions. The coal permeability model can be used to obtain critical coal parameters that can be applied in field models. An economic feasibility study of CO2 sequestration in unminable coal seams in the Powder River Basin of Wyoming was done. Economic analyses of CO2 injection options are compared. Results show that injecting flue gas to recover methane from CBM fields is marginally economical; however, this method will not significantly contribute to the need to sequester large quantities of CO2. Separating CO2 from flue gas and injecting it into the unminable coal zones of the Powder River Basin seam is currently uneconomical, but can effectively sequester over 86,000 tons (78,200 Mg) of CO2 per acre while recovering methane to offset costs. The cost to separate CO2 from flue gas was identified as the major cost driver associated with CO2 sequestration in unminable coal seams. Improvements in separations technology alone are unlikely to drive costs low enough for CO2 sequestration in unminable coal seams in the Powder River Basin to become economically viable. Breakthroughs in separations technology could aid the economics, but in the Powder River Basin, they cannot achieve the necessary cost reductions for breakeven economics without incentives.

  8. Causes and consequences of institutional practices in organizations: routines, trust, and identity

    E-Print Network [OSTI]

    Schilke, Oliver Siegfried

    2014-01-01

    of the new institutionalism: the causes and consequences ofOF CALIFORNIA Los Angeles Causes and consequences ofOF THE DISSERTATION Causes and consequences of institutional

  9. Causes and Consequences of Second Language Education: A Global Analysis From 1980 to the Present

    E-Print Network [OSTI]

    Coyne, Gary

    2013-01-01

    OF CALIFORNIA RIVERSIDE Causes and Consequences of SecondOF THE DISSERTATION Causes and Consequences of Seconddissertation examines the causes and consequences of second

  10. The design of a fluidized bed for testing of a robotic burrowing device which mimics razor clams

    E-Print Network [OSTI]

    Dorsch, Daniel Scott

    2012-01-01

    This thesis reviews the design of a fluidized bed test setup for testing digging kinematics of RoboClam, a burrowing device based on Atlantic Razor Clams. This test bed allows for in-lab testing in an environment covered ...

  11. Some Consequences of Dark Energy Density varying Exponentially with Scale Factor

    E-Print Network [OSTI]

    Sanil Unnikrishnan; T. R. Seshadri

    2005-11-10

    In this paper we have explored the consequences of a model of dark energy with its energy density varying exponentially with the scale factor. We first consider the model with $ \\rho_{\\phi} \\propto e^{\\kappa a} $, where $\\kappa $ is a constant. This is a kind of generalisation of the cosmological constant model with $\\kappa = 0$. We show that such an exponentially varying dark energy density with the scale factor naturally leads to an equivalent phantom field. We also consider a model with $ \\rho_{\\phi} \\propto e^{\\kappa /a} $ and we show that this also naturally leads to an equivalent phantom field.

  12. Thermal Design of a Metal Hydride Storage Bed, Permitting Tritium Accountancy to 0.1% Resolution and Repeatability

    E-Print Network [OSTI]

    Thermal Design of a Metal Hydride Storage Bed, Permitting Tritium Accountancy to 0.1% Resolution and Repeatability

  13. A general formula for non-cohesive bed load sediment transport Benoi^t Camenen), Magnus Larson

    E-Print Network [OSTI]

    US Army Corps of Engineers

    A general formula for non-cohesive bed load sediment transport Benoi^t Camenen), Magnus Larson 2004; accepted 29 October 2004 Abstract A bed load transport formula for non-cohesive sediment, based, oscillatory flows, and combined steady and oscillatory flows. The bed load formula introduced in this study

  14. A new bed material sediment sampler 2277 Copyright 2008 John Wiley & Sons, Ltd. Earth Surf. Process. Landforms 33, 22772284 (2008)

    E-Print Network [OSTI]

    Singer, Michael

    2008-01-01

    A new bed material sediment sampler 2277 Copyright © 2008 John Wiley & Sons, Ltd. Earth Surf.interscience.wiley.com) DOI: 10.1002/esp.1661 Technical Communication A new sampler for extracting bed material sediment from Abstract Grain-size distributions of bed material sediment in large alluvial rivers are required in various

  15. The development of a 20-inch indirect fired fluidized bed gasifier

    SciTech Connect (OSTI)

    Flanigan, V.J.; Sitton, O.C.; Huang, W.E

    1988-03-01

    This report discusses the design, fabrication and operation of a 20'' I.D. fluidized bed gasifier producing medium Btu gas. The reactor is indirectly heated using 30 x 1-inch U-tubes inserted in the inert bed. The U-tubes are heated using flue gases produced from a propane burner system located at the bottom of the reactor. The feed material was dry wood chips fed into the bed with a 6in. auger. The reactor was fed both into the bed and at the top of the bed. The fluidizing medium was superheated steam which was superheated to 1000/degree/F. The gas produced from the reactor was passed through a cyclone for char removal and routed to the flare for combustion and disposal. The parameters measured during the experimental runs were wood feed rate, steam flow rate, steam temperatures, bed temperatures, free board temperatures, product gas temperatures, bed differential pressures, char production, gas production, gas analyses, and tar production. The parameters measured in the laboratory were moisture contents (wood and char), ash contents (wood and char), and tar content. 9 refs., 19 figs., 11 tabs.

  16. Fluidized-bed catalytic coal-gasification process. [US patent; pretreatment to minimize agglomeration

    DOE Patents [OSTI]

    Euker, C.A. Jr.; Wesselhoft, R.D.; Dunkleman, J.J.; Aquino, D.C.; Gouker, T.R.

    1981-09-14

    Coal or similar carbonaceous solids impregnated with gasification catalyst constituents are oxidized by contact with a gas containing between 2 vol % and 21 vol % oxygen at a temperature between 50 and 250/sup 0/C in an oxidation zone and the resultant oxidized, catalyst impregnated solids are then gasified in a fluidized bed gasification zone at an elevated pressure. The oxidation of the catalyst impregnated solids under these conditions insures that the bed density in the fluidized bed gasification zone will be relatively high even though the solids are gasified at elevated pressure and temperature.

  17. Fluidized bed heat exchanger with water cooled air distributor and dust hopper

    DOE Patents [OSTI]

    Jukkola, Walfred W. (Westport, CT); Leon, Albert M. (Mamaroneck, NY); Van Dyk, Jr., Garritt C. (Bethel, CT); McCoy, Daniel E. (Williamsport, PA); Fisher, Barry L. (Montgomery, PA); Saiers, Timothy L. (Williamsport, PA); Karstetter, Marlin E. (Loganton, PA)

    1981-11-24

    A fluidized bed heat exchanger is provided in which air is passed through a bed of particulate material containing fuel. A steam-water natural circulation system is provided for heat exchange and the housing of the heat exchanger has a water-wall type construction. Vertical in-bed heat exchange tubes are provided and the air distributor is water-cooled. A water-cooled dust hopper is provided in the housing to collect particulates from the combustion gases and separate the combustion zone from a volume within said housing in which convection heat exchange tubes are provided to extract heat from the exiting combustion gases.

  18. Production of activated carbon from coconut shell char in a fluidized bed reactor

    SciTech Connect (OSTI)

    Sai, P.M.S.; Ahmed, J. [Bhabha Atomic Research Centre, Kalpakkam (India). Centralised Waste Management Facility; Krishnaiah, K. [Indian Inst. of Tech., Madras (India). Dept. of Chemical Engineering

    1997-09-01

    Activated carbon is produced from coconut shell char using steam or carbon dioxide as the reacting gas in a 100 mm diameter fluidized bed reactor. The effect of process parameters such as reaction time, fluidizing velocity, particle size, static bed height, temperature of activation, fluidizing medium, and solid raw material on activation is studied. The product is characterized by determination of iodine number and BET surface area. The product obtained in the fluidized bed reactor is much superior in quality to the activated carbons produced by conventional processes. Based on the experimental observations, the optimum values of process parameters are identified.

  19. National Security Consequences of U.S. Oil Dependency

    E-Print Network [OSTI]

    Deutch, John

    cfr National Security Consequences of U.S. Oil Dependency Report of an Independent Task Force Uncorrected Proofs #12;Founded in 1921, the Council on Foreign Relations is an independent, national

  20. 1 Economics The study of economics investigates the consequences of

    E-Print Network [OSTI]

    Vertes, Akos

    1 Economics ECONOMICS The study of economics investigates the consequences of scarcity, which forces people, organizations and governments to choose among competing objectives. Economics looks, unemployment, inflation, economic growth and the use and distribution of resources within and across nations

  1. The strategic consequences of the oil price collapse

    SciTech Connect (OSTI)

    Schuler, H.

    1987-01-01

    This book discusses the geopolitical consequences of the oil-price drop in such countries as Indonesia, Nigeria, Algeria, Mexico and Egypt. It also assesses the overall implications of the drop in oil prices on oil-producing areas.

  2. The Latest Unanticipated Consequence in the Ethanol Fiasco 

    E-Print Network [OSTI]

    Griffin, James M.

    2013-01-01

    Until recently, the 2007 ethanol mandates have been a story of very small environmental and security benefits and large, unexpected increases in food prices as corn was diverted from food to fuel uses. Now we have another unforeseen consequence...

  3. Atmospheric consequences of cosmic ray variability in the extragalactic shock model: 2. Revised ionization levels and their consequences

    E-Print Network [OSTI]

    Melott, Adrian L.; Atri, Dimitra; Thomas, Brian C.; Medvedev, Mikhail V.; Wilson, Graham Wallace; Murray, Michael J.

    2010-08-19

    It has been suggested that galactic shock asymmetry induced by our galaxy's infall toward the Virgo Cluster may be a source of periodicity in cosmic ray exposure as the solar system oscillates perpendicular to the galactic plane, thereby, inducing...

  4. SU-E-T-510: Mathematical Analysis of Approximate Biological Effective Dose (BED) Calculation for Multi-Phase Radiotherapy Treatment Plans

    SciTech Connect (OSTI)

    Kauweloa, K; Gutierrez, A; Bergamo, A; Stathakis, S; Papanikolaou, N; Mavroidis, P

    2014-06-01

    Purpose: There is growing interest about biological effective dose (BED) and its application in treatment plan evaluation due to its stronger correlation with treatment outcome. An approximate biological effective dose (BEDA) equation was introduced to simplify BED calculations by treatment planning systems in multi-phase treatments. The purpose of this work is to reveal its mathematical properties relative to the true, multi-phase BED (BEDT) equation. Methods: The BEDT equation was derived and used to reveal the mathematical properties of BEDA. MATLAB (MathWorks, Natick, MA) was used to simulate and analyze common and extreme clinical multi-phase cases. In those cases, percent error (Perror) and Bland-Altman analysis were used to study the significance of the inaccuracies of BEDA for different combinations of total doses, numbers of fractions, doses per fractions and ? over ? values. All the calculations were performed on a voxel-basis in order to study how dose distributions would affect the accuracy of BEDA. Results: When the voxel dose-per-fractions (DPF) delivered by both phases are equal, BEDA and BEDT are equal. In heterogeneous dose distributions, which significantly vary between the phases, there are fewer occurrences of equal DPFs and hence the imprecision of BEDA is greater. It was shown that as the ? over ? ratio increased the accuracy of BEDA would improve. Examining twenty-four cases, it was shown that the range of DPF ratios for a 3 Perror varied from 0.32 to 7.50Gy, whereas for Perror of 1 the range varied from 0.50 to 2.96Gy. Conclusion: The DPF between the different phases should be equal in order to render BEDA accurate. OARs typically receive heterogeneous dose distributions hence the probability of equal DPFs is low. Consequently, the BEDA equation should only be used for targets or OARs that receive uniform or very similar dose distributions by the different treatment phases.

  5. Temporal analysis of acoustic emission from a plunged granular bed

    E-Print Network [OSTI]

    Daisuke Tsuji; Hiroaki Katsuragi

    2015-09-18

    The statistical property of acoustic emission (AE) events from a plunged granular bed is analyzed by means of actual time and natural time analyses. These temporal analysis methods allow us to investigate the details of AE events that follow a power-law distribution. In the actual time analysis, the calm time distribution and the decay of the event-occurrence density after the largest event (i.e., Omori-Utsu law) are measured. Although the former always shows a power-law form, the latter does not always obey a power law. Markovianity of the event-occurrence process is also verified using a scaling law by assuming that both of them exhibit power laws. We find that the effective shear strain rate is a key parameter to classify the emergence rate of power-law nature and Markovianity in the granular AE events. For the natural time analysis, the existence of self organized critical (SOC) states is revealed by calculating the variance of natural time $\\chi_k$, where $k$th natural time of N events is defined as $\\chi_k=k/N$. In addition, the energy difference distribution can be fitted by a $q$-Gaussian form, which is also consistent with the criticality of the system.

  6. Heavy oil upgrading via fluidized bed processing and hydrogenation processing

    SciTech Connect (OSTI)

    Dawson, F.N. Jr. [California Synfuels Research Corp., Palos Verdes, CA (United States)

    1995-09-01

    California is the second largest crude oil producer in the lower 48 states. Nearly half of its production is heavy oil, difficult to transport and costly to refine. Given better methods of processing, production could be expanded. Likewise, huge worldwide reserves of heavy oils could be better exploited if more attractive processing methods were available. Midway Sunset crude at 11.8 API gravity, is a fairly difficult crude to process. It has about 1.5 percent sulfur, a very high nitrogen content, in the range of 0.7--0.8%, and metals of approximately 120--170 ppm, vanadium plus nickel. The authors will be reporting here results of the pilot plant testing to see whether non-catalytic fluid bed cracking technology, operated at low conversion, followed by hydrogenation would be economically attractive. Results suggest that this approach is competitive with delayed coking and with atmospheric resid desulfurization. This approach successfully combines carbon removal and hydrogen addition techniques for heavy oil upgrading. Comparative yields, product quality and economic considerations are reviewed in this study.

  7. CAVERN ROOF STABILITY FOR NATURAL GAS STORAGE IN BEDDED SALT

    SciTech Connect (OSTI)

    DeVries, Kerry L; Mellegard, Kirby D; Callahan, Gary D; Goodman, William M

    2005-06-01

    This report documents research performed to develop a new stress-based criterion for predicting the onset of damage in salt formations surrounding natural gas storage caverns. Laboratory tests were conducted to investigate the effects of shear stress, mean stress, pore pressure, temperature, and Lode angle on the strength and creep characteristics of salt. The laboratory test data were used in the development of the new criterion. The laboratory results indicate that the strength of salt strongly depends on the mean stress and Lode angle. The strength of the salt does not appear to be sensitive to temperature. Pore pressure effects were not readily apparent until a significant level of damage was induced and the permeability was increased to allow penetration of the liquid permeant. Utilizing the new criterion, numerical simulations were used to estimate the minimum allowable gas pressure for hypothetical storage caverns located in a bedded salt formation. The simulations performed illustrate the influence that cavern roof span, depth, roof salt thickness, shale thickness, and shale stiffness have on the allowable operating pressure range. Interestingly, comparison of predictions using the new criterion with that of a commonly used criterion indicate that lower minimum gas pressures may be allowed for caverns at shallow depths. However, as cavern depth is increased, less conservative estimates for minimum gas pressure were determined by the new criterion.

  8. Circulating fluidized-bed boiler makes inroads for waste recycling

    SciTech Connect (OSTI)

    1995-09-01

    Circulating fluidized-bed (CFB) boilers have ben used for years in Scandinavia to burn refuse-derived fuel (RDF). Now, Foster Wheeler Power Systems, Inc., (Clinton, N.J.) is bringing the technology to the US. Touted as the world`s largest waste-to-energy plant to use CFB technology, the Robbins (III.) Resource Recovery Facility will have the capacity to process 1,600 tons/d of municipal solid waste (MSW) when it begins operation in early 1997. The facility will have two materials-separation and RDF-processing trains, each with dual trommel screens, magnetic and eddy current separators, and shredders. About 25% of the incoming MSW will be sorted and removed for recycling, while 75% of it will be turned into fuel, with a heat value of roughly 6,170 btu/lb. Once burned in the twin CFB boilers the resulting steam will be routed through a single turbine generator to produce 50,000 mW of electric power.

  9. FLUIDIZED BED STEAM REFORMING ENABLING ORGANIC HIGH LEVEL WASTE DISPOSAL

    SciTech Connect (OSTI)

    Williams, M

    2008-05-09

    Waste streams planned for generation by the Global Nuclear Energy Partnership (GNEP) and existing radioactive High Level Waste (HLW) streams containing organic compounds such as the Tank 48H waste stream at Savannah River Site have completed simulant and radioactive testing, respectfully, by Savannah River National Laboratory (SRNL). GNEP waste streams will include up to 53 wt% organic compounds and nitrates up to 56 wt%. Decomposition of high nitrate streams requires reducing conditions, e.g. provided by organic additives such as sugar or coal, to reduce NOX in the off-gas to N2 to meet Clean Air Act (CAA) standards during processing. Thus, organics will be present during the waste form stabilization process regardless of the GNEP processes utilized and exists in some of the high level radioactive waste tanks at Savannah River Site and Hanford Tank Farms, e.g. organics in the feed or organics used for nitrate destruction. Waste streams containing high organic concentrations cannot be stabilized with the existing HLW Best Developed Available Technology (BDAT) which is HLW vitrification (HLVIT) unless the organics are removed by pretreatment. The alternative waste stabilization pretreatment process of Fluidized Bed Steam Reforming (FBSR) operates at moderate temperatures (650-750 C) compared to vitrification (1150-1300 C). The FBSR process has been demonstrated on GNEP simulated waste and radioactive waste containing high organics from Tank 48H to convert organics to CAA compliant gases, create no secondary liquid waste streams and create a stable mineral waste form.

  10. Treating exhaust gas from a pressurized fluidized bed reaction system

    DOE Patents [OSTI]

    Isaksson, J.; Koskinen, J.

    1995-08-22

    Hot gases from a pressurized fluidized bed reactor system are purified. Under super atmospheric pressure conditions hot exhaust gases are passed through a particle separator, forming a filtrate cake on the surface of the separator, and a reducing agent--such as an NO{sub x} reducing agent (like ammonia)--is introduced into the exhaust gases just prior to or just after particle separation. The retention time of the introduced reducing agent is enhanced by providing a low gas velocity (e.g. about 1--20 cm/s) during passage of the gas through the filtrate cake while at super atmospheric pressure. Separation takes place within a distinct pressure vessel, the interior of which is at a pressure of about 2--100 bar, and introduction of reducing agent can take place at multiple locations (one associated with each filter element in the pressure vessel), or at one or more locations just prior to passage of clean gas out of the pressure vessel (typically passed to a turbine). 8 figs.

  11. Deep Bed Adsorption Testing using Silver-Functionalized Aerogel

    SciTech Connect (OSTI)

    Nick Soelberg; Tony Watson

    2012-06-01

    Nuclear fission results in the production of fission products and activation products, some of which tend to be volatile during used fuel reprocessing and evolve in gaseous species into the reprocessing facility off-gas systems. Analyses have shown that I129, due to its radioactivity, high potential mobility in the environment, and high longevity (half life of 15.7 million years), can require control efficiencies of up to 1,000x or higher to meet regulatory emission limits. Two Aerogel sorption tests that have been performed this fiscal year. The maximum iodine decontamination factor (DF) was measured to be over 10,000, above the 1,000-10,000 target DF range. The mass transfer zone may be as short as 0.5 inches under the sorption conditions of the first test. Only a small fraction of the iodine sorbed on Bed 1 was desorbed during the purge periods. The silver-functionalized Aerogel appears to have potential to be a very effective and efficient iodine sorbent.

  12. Treating exhaust gas from a pressurized fluidized bed reaction system

    DOE Patents [OSTI]

    Isaksson, Juhani (Karhula, FI); Koskinen, Jari (Karhula, FI)

    1995-01-01

    Hot gases from a pressurized fluidized bed reactor system are purified. Under superatmospheric pressure conditions hot exhaust gases are passed through a particle separator, forming a flitrate cake on the surface of the separator, and a reducing agent--such as an NO.sub.x reducing agent (like ammonia), is introduced into the exhaust gases just prior to or just after particle separation. The retention time of the introduced reducing agent is enhanced by providing a low gas velocity (e.g. about 1-20 cm/s) during passage of the gas through the filtrate cake while at superatmospheric pressure. Separation takes place within a distinct pressure vessel the interior of which is at a pressure of about 2-100 bar, and-introduction of reducing agent can take place at multiple locations (one associated with each filter element in the pressure vessel), or at one or more locations just prior to passage of clean gas out of the pressure vessel (typically passed to a turbine).

  13. Repowering with pressurized fluidized-bed combustion units

    SciTech Connect (OSTI)

    Goidich, S.J. ); Rubow, L.N. ); Kumar, S. . Environmental Services and Technologies Div.); Mukherjee, D. ); Childress, N.B. )

    1991-05-01

    Turbocharged pressurized fluidized bed combustion (PFBC) power plants operating with a gas turbine inlet temperature lower than 800{degrees}F can produce electricity more efficiently (34.2 vs. 33.5% net plant efficiency) and at a lower cost of electricity (87.8 vs. 96. 6 mill/kWh over 30 years) than conventional pulverized-coal-fired plants with scrubbers. Since the PFBC process produces lower NO{sub x} emissions than conventional pulverized-coal combustion systems and captures sulfur as part of the combustion process, and since major equipment components can be shop-assembled and shipped by barge, retrofit of an existing unit with a turbocharged PFBC boiler can be a cost-effective means for extending the life of the unit and meeting NSPS without retrofitting flue gas desulfurization systems. Using the Wisconsin Electric Power Company's Port Washington Unit 5 as an example, preliminary engineering and economic evaluations were made to investigate the merits of turbocharged PFBC retrofits. This report describes the conceptual designs of the new, major plant components; discusses how the new components are integrated with the existing balance-of-plant equipment; describes the proposed plant control system; and presents an overall economic evaluation. Because design and economic evaluations were prepared on the basis of a commercial design, first-of-a-kind costs and test programs are not included. 5 refs., 58 figs., 55 tabs.

  14. OSPREY Model

    SciTech Connect (OSTI)

    Veronica J. Rutledge

    2013-01-01

    The absence of industrial scale nuclear fuel reprocessing in the U.S. has precluded the necessary driver for developing the advanced simulation capability now prevalent in so many other countries. Thus, it is essential to model complex series of unit operations to simulate, understand, and predict inherent transient behavior and feedback loops. A capability of accurately simulating the dynamic behavior of advanced fuel cycle separation processes will provide substantial cost savings and many technical benefits. The specific fuel cycle separation process discussed in this report is the off-gas treatment system. The off-gas separation consists of a series of scrubbers and adsorption beds to capture constituents of interest. Dynamic models are being developed to simulate each unit operation involved so each unit operation can be used as a stand-alone model and in series with multiple others. Currently, an adsorption model has been developed within Multi-physics Object Oriented Simulation Environment (MOOSE) developed at the Idaho National Laboratory (INL). Off-gas Separation and REcoverY (OSPREY) models the adsorption of off-gas constituents for dispersed plug flow in a packed bed under non-isothermal and non-isobaric conditions. Inputs to the model include gas, sorbent, and column properties, equilibrium and kinetic data, and inlet conditions. The simulation outputs component concentrations along the column length as a function of time from which breakthrough data is obtained. The breakthrough data can be used to determine bed capacity, which in turn can be used to size columns. It also outputs temperature along the column length as a function of time and pressure drop along the column length. Experimental data and parameters were input into the adsorption model to develop models specific for krypton adsorption. The same can be done for iodine, xenon, and tritium. The model will be validated with experimental breakthrough curves. Customers will be given access to OSPREY to used and evaluate the model.

  15. Reservoir Characterization and Modeling of the Glorieta and the Clearfork Formations, Monahans Field, Permian Basin, Texas 

    E-Print Network [OSTI]

    Yeatman, Ryan Yeatman

    2012-10-19

    facies model, porosity model, and a siltstone model were generated in Petrel to better characterize the Monahans Field reservoir. Interbedded impermeable siltstone beds in Monahans Field partition the reservoir making oil production and water injection...

  16. Fluid Bed Waste Heat Boiler Operating Experience in Dirty Gas Streams 

    E-Print Network [OSTI]

    Kreeger, A. H.

    1986-01-01

    BOILER OPERATING EXPERIENCE IN DIRTY GAS STREAMS Alan H. Kreeger. Aerojet Energy Conversion Company. Sacramento. California ABSTRACT The first industrial fluid bed waste heat boiler in the U. S. is operating on an aluminium melting furnace...

  17. Shape and dynamics of seepage erosion in a horizontal granular bed

    E-Print Network [OSTI]

    Berhanu, Michael

    We investigate erosion patterns observed in a horizontal granular bed resulting from seepage of water motivated by observation of beach rills and channel growth in larger scale land forms. Our experimental apparatus consists ...

  18. Rotary bed reactor for chemical-looping combustion with carbon capture

    E-Print Network [OSTI]

    Zhao, Zhenlong

    2012-01-01

    Chemical-looping combustion (CLC) is a novel and promising technology for power generation with inherent CO2 capture. Currently almost all the research has been focused on developing CLC based inter-connected fluidized bed ...

  19. Design, analysis and optimization of the power conversion system for the Modular Pebble Bed Reactor System

    E-Print Network [OSTI]

    Wang, Chunyun, 1968-

    2003-01-01

    The Modular Pebble Bed Reactor system (MPBR) requires a gas turbine cycle (Brayton cycle) as the power conversion system for it to achieve economic competitiveness as a GenIV nuclear system. The availability of controllable ...

  20. Packed-Bed Reactor Study of NETL Sample 196c for the Removal...

    Office of Scientific and Technical Information (OSTI)

    Reactor Study of NETL Sample 196c for the Removal of Carbon Dioxide from Simulated Flue Gas Mixture Citation Details In-Document Search Title: Packed-Bed Reactor Study of NETL...

  1. Method and apparatus for improving heat transfer in a fluidized bed

    DOE Patents [OSTI]

    Lessor, Delbert L. (Richland, WA); Robertus, Robert J. (Richland, WA)

    1990-01-01

    An apparatus contains a fluidized bed that includes particles of different triboelectrical types, each particle type acquiring an opposite polarity upon contact. The contact may occur between particles of the two types or between particles of etiher type and structure or fluid present in the apparatus. A fluidizing gas flow is passed through the particles to produce the fluidized bed. Immersed within the bed are electrodes. An alternating EMF source connected to the electrodes applies an alternating electric field across the fluidized bed to cause particles of the first type to move relative to particles of the second type and relative to the gas flow. In a heat exchanger incorporating the apparatus, the electrodes are conduits conveying a fluid to be heated. The two particle types alternately contact each conduit to transfer heat from a hot gas flow to the second fluid within the conduit.

  2. Characterization of Thin-Bedded Reservoir in the Gulf of Mexico: An Integrated Approach. 

    E-Print Network [OSTI]

    Lalande, Severine

    2004-09-30

    complex but the quality of the reservoir is determined by connection and length of beds below the resolution of usual reflection data. Improved characterization is needed to improve development and production of these reservoirs. This study presents...

  3. Low cost monitoring system to diagnose problematic rail bed : case study of Mud Pumping Site

    E-Print Network [OSTI]

    Aw, Eng Sew, 1978-

    2007-01-01

    This thesis describes the development of low cost sensors and wireless sensor network (WSN) platform aimed at characterizing problematic rail beds (subgrade). The instrumentations are installed at a busy high-speed Northeast ...

  4. Electrically recharged battery employing a packed/spouted bed metal particle electrode

    DOE Patents [OSTI]

    Siu, Stanley C. (Alameda, CA); Evans, James W. (Piedmont, CA); Salas-Morales, Juan (Berkeley, CA)

    1995-01-01

    A secondary metal air cell, employing a spouted/packed metal particle bed and an air electrode. More specifically a zinc air cell well suited for use in electric vehicles which is capable of being either electrically or hydraulically recharged.

  5. Pulsed atmospheric fluidized bed combustion. Quarterly technical progress report, July 1992--September 1992

    SciTech Connect (OSTI)

    Not Available

    1992-10-01

    The design of the Pulsed Atmospheric Fluidized Bed Combustor (PAFBC) as described in the Quarterly Report for the period April--June, 1992 was reviewed and minor modifications were included. The most important change made was in the coal/limestone preparation and feed system. Instead of procuring pre-sized coal for testing of the PAFBC, it was decided that the installation of a milling system would permit greater flexibility in the testing with respect to size distributions and combustion characteristics in the pulse combustor and the fluid bed. Particle size separation for pulse combustor and fluid bed will be performed by an air classifier. The modified process flow diagram for the coal/limestone handling system is presented in Figure 1. The modified process flow diagrams of the fluidized bed/steam cycle and ash handling systems are presented in Figures 2 and 3, respectively.

  6. Management and Conservation Article Bed Site Selection by Neonate Deer in

    E-Print Network [OSTI]

    , white-tailed deer. Previous research documented variable behavior of adult female white-tailed deer the dam returns to groom and nurse (Huegel et al. 1986). Choice of bed site is typically limited

  7. Bedmap2: improved ice bed, surface and thickness datasets for Antarctica

    E-Print Network [OSTI]

    Fretwell, P.; Pritchard, H. D.; Vaughan, D. G.; Bamber, J. L.; Barrand, N. E.; Bell, R.; Bianchi, C.; Bingham, R. G.; Blankenship, D. D.; Casassa, G.; Catania, G.; Callens, D.; Conway, H.; Cook, A. J.; Corr, H. F. J.; Damaske, D.; Damm, V.; Ferraccioli, F.; Forsberg, R.; Fujita, S.; Gim, Y.; Gogineni, Sivaprasad; Griggs, J. A.; Hindmarsh, R.; Holmlund, P.; Holt, J. W.; Jacobel, R. W.; Jenkins, A.; Jokat, W.; Jordan, T.; King, E. C.; Kohler, J.; Krabill, W.; Riger-Kusk, M.; Langley, K. A.; Leitchenkov, G.; Leuschen, Carl; Lyendyk, B. P.; Matsuoka, K.; Mouginot, J.; Nitsche, F. O.; Nogi, Y.; Nost, O. A.; Popov, S. V.; Rignot, E.; Rippin, D. M.; Rivera, A.; Roberts, J.; Roberts, J.; Ross, N.; Siegert, M. J.; Smith, A. M.; Steinhage, D.; Studinger, M.; Sun, B.; Tinto, B. K.; Welch, B. C.; Wilson, D.; Young, D. A.; Xiangbin, C.; Zirizzotti, A.

    2013-02-28

    We present Bedmap2, a new suite of gridded products describing surface elevation, ice-thickness and the seafloor and subglacial bed elevation of the Antarctic south of 60° S. We derived these products using data from a ...

  8. Design and performance of a high-pressure Fischer-Tropsch fluidized bed reactor

    SciTech Connect (OSTI)

    Weimer, A.W.; Quarderer, G.J.; Cochran, G.A.; Conway, M.M. )

    1988-01-01

    A 900 kg/day, CO/H/sub 2/, high-pressure, fluidized bed, pilot reactor was designed from first principles to achieve high reactant conversions and heat removal rates for the Fischer-Tropsch (F-T) synthesis of liquefied petroleum gases (LPG's). Suppressed bubble growth at high pressure allowed high reactant conversions which nearly matched those obtained at identical conditions in a lab scale fixed bed reactor. For GHSV approximately 1400 hr/sup -1/ and T = 658 {Kappa} at P approximately 7000 {kappa}Pa, reactant conversion exceeded 75%. The reactor heat removal capability exceeded twice design performance with the fluidized bed easily operating under thermally stable conditions. The fluidized catalyst was a potassium promoted, molybdenum on carbon (Mo/{Kappa}/C) catalyst which did not produce any detrimental waxy products. Long catalyst lifetimes of 1000 hrs on steam between regenerations allowed the fluidized bed to be operated in a batch mode.

  9. Design and Operation of Fluid Beds for Heating, Cooling and Quenching Operations 

    E-Print Network [OSTI]

    Kemp, W. E.

    1981-01-01

    A commercial foundry has been established which makes extensive use of fluid beds in the production of heat treated alloy steel castings. The castings are cooled immediately after solidification by fluidizing the mold sand in which they were cast...

  10. Catalytic hydrodechlorination of industrial wastewater containing chlorinated hydrocarbons in a trickle bed reactor 

    E-Print Network [OSTI]

    Leong, Chee Kong

    1996-01-01

    been demonstrated as a viable wastewater remediation technique with a half-inch co-current down flow trickle bed reactor. Hydrodechlorination reactions were conducted over a 1% and a 2% palladium on carbon catalyst at a fixed system pressure...

  11. Operating Experience of a Coal Fired Fluidized Bed at Georgetown University 

    E-Print Network [OSTI]

    Lutes, I. G.; Gamble, R. L.

    1980-01-01

    Operation of the 100,000 lb/hr capacity, coal fired fluidized bed steam generator at Georgetown University began in July 1979. This project, which was co-funded by Georgetown University and the U. S. Department of Energy, ...

  12. Experimental Study and Computational Simulations of Key Pebble Bed Thermo-mechanics Issues for Design and Safety

    SciTech Connect (OSTI)

    Tokuhiro, Akira; Potirniche, Gabriel; Cogliati, Joshua; Ougouag, Abderrafi

    2014-07-08

    An experimental and computational study, consisting of modeling and simulation (M&S), of key thermal-mechanical issues affecting the design and safety of pebble-bed (PB) reactors was conducted. The objective was to broaden understanding and experimentally validate thermal-mechanic phenomena of nuclear grade graphite, specifically, spheres in frictional contact as anticipated in the bed under reactor relevant pressures and temperatures. The contact generates graphite dust particulates that can subsequently be transported into the flowing gaseous coolent. Under postulated depressurization transients and with the potential for leaked fission products to be adsorbed onto graphite 'dust', there is the potential for fission products to escape from the primary volume. This is a design safety concern. Furthermore, earlier safety assessment identified the distinct possibility for the dispersed dust to combust in contact with air if sufficient conditions are met. Both of these phenomena were noted as important to design review and containing uncertainty to warrant study. The team designed and conducted two separate effects tests to study and benchmark the potential dust-generation rate, as well as study the conditions under which a dust explosion may occure in a standardized, instrumented explosion chamber.

  13. The development of an integrated multistaged fluid-bed retorting process. Final report, September 1990--August 1994

    SciTech Connect (OSTI)

    Carter, S.D.; Taulbee, D.N.; Stehn, J.L.; Vego, A.; Robl, T.L.

    1995-02-01

    This summarizes the development of the KENTORT II retorting process, which includes integral fluidized bed zones for pyrolysis, gasification, and combustion of oil shale. Purpose was to design and test the process at the 50-lb/hr scale. The program included bench- scale studies of coking and cracking reactions of shale oil vapors over processed shale particles to address issues of scaleup associated with solid-recycle retorting. The bench-scale studies showed that higher amounts of carbon coverage reduce the rate of subsequent carbon deposition by shale oil vapors onto processed shale particles; however carbon-covered materials were also active in terms of cracking and coking. Main focus was the 50-lb/hr KENTORT II PDU. Cold-flow modeling and shakedown were done before the PDU was made ready for operation. Seven mass-balanced, steady-state runs were completed within the window of design operating conditions. Goals were achieved: shale feedrate, run duration (10 hr), shale recirculation rates (4:1 to pyrolyzer and 10:1 to combustor), bed temperatures (pyrolyzer 530{degree}C, gasifier 750{degree}C, combustor 830{degree}C), and general operating stability. Highest oil yields (up to 109% of Fischer assay) were achieved for runs lasting {ge} 10 hours. High C content of the solids used for heat transfer to the pyrolysis zone contributed to the enhanced oil yield achieved.

  14. Probabilistic accident consequence uncertainty analysis -- Early health effects uncertainty assessment. Volume 2: Appendices

    SciTech Connect (OSTI)

    Haskin, F.E. [Univ. of New Mexico, Albuquerque, NM (United States); Harper, F.T. [Sandia National Labs., Albuquerque, NM (United States); Goossens, L.H.J.; Kraan, B.C.P. [Delft Univ. of Technology (Netherlands)

    1997-12-01

    The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the US Nuclear Regulatory Commission and the Commission of the European Communities began cosponsoring a joint uncertainty analysis of the two codes. The ultimate objective of this joint effort was to systematically develop credible and traceable uncertainty distributions for the respective code input variables. A formal expert judgment elicitation and evaluation process was identified as the best technology available for developing a library of uncertainty distributions for these consequence parameters. This report focuses on the results of the study to develop distribution for variables related to the MACCS and COSYMA early health effects models. This volume contains appendices that include (1) a summary of the MACCS and COSYMA consequence codes, (2) the elicitation questionnaires and case structures, (3) the rationales and results for the panel on early health effects, (4) short biographies of the experts, and (5) the aggregated results of their responses.

  15. Probabilistic accident consequence uncertainty analysis -- Uncertainty assessment for deposited material and external doses. Volume 2: Appendices

    SciTech Connect (OSTI)

    Goossens, L.H.J.; Kraan, B.C.P.; Cooke, R.M. [Delft Univ. of Technology (Netherlands); Boardman, J. [AEA Technology (United Kingdom); Jones, J.A. [National Radiological Protection Board (United Kingdom); Harper, F.T.; Young, M.L. [Sandia National Labs., Albuquerque, NM (United States); Hora, S.C. [Univ. of Hawaii, Hilo, HI (United States)

    1997-12-01

    The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the US Nuclear Regulatory Commission and the Commission of the European Communities began cosponsoring a joint uncertainty analysis of the two codes. The ultimate objective of this joint effort was to systematically develop credible and traceable uncertainty distributions for the respective code input variables. A formal expert judgment elicitation and evaluation process was identified as the best technology available for developing a library of uncertainty distributions for these consequence parameters. This report focuses on the results of the study to develop distribution for variables related to the MACCS and COSYMA deposited material and external dose models. This volume contains appendices that include (1) a summary of the MACCS and COSYMA consequence codes, (2) the elicitation questionnaires and case structures, (3) the rationales and results for the panel on deposited material and external doses, (4) short biographies of the experts, and (5) the aggregated results of their responses.

  16. Probabilistic accident consequence uncertainty analysis -- Uncertainty assessment for internal dosimetry. Volume 2: Appendices

    SciTech Connect (OSTI)

    Goossens, L.H.J.; Kraan, B.C.P.; Cooke, R.M.; Harrison, J.D.; Harper, F.T.; Hora, S.C.

    1998-04-01

    The development of two new probabilistic accident consequence codes, MACCS and COSYMA, was completed in 1990. These codes estimate the consequence from the accidental releases of radiological material from hypothesized accidents at nuclear installations. In 1991, the US Nuclear Regulatory Commission and the Commission of the European Communities began cosponsoring a joint uncertainty analysis of the two codes. The ultimate objective of this joint effort was to systematically develop credible and traceable uncertainty distributions for the respective code input variables. A formal expert judgment elicitation and evaluation process was identified as the best technology available for developing a library of uncertainty distributions for these consequence parameters. This report focuses on the results of the study to develop distribution for variables related to the MACCS and COSYMA internal dosimetry models. This volume contains appendices that include (1) a summary of the MACCS and COSYMA consequence codes, (2) the elicitation questionnaires and case structures, (3) the rationales and results for the panel on internal dosimetry, (4) short biographies of the experts, and (5) the aggregated results of their responses.

  17. Investigation of Gas Solid Fluidized Bed Dynamics with Non-Spherical Particles

    SciTech Connect (OSTI)

    Choudhuri, Ahsan

    2013-06-30

    One of the largest challenges for 21st century is to fulfill global energy demand while also reducing detrimental impacts of energy generation and use on the environment. Gasification is a promising technology to meet the requirement of reduced emissions without compromising performance. Coal gasification is not an incinerating process; rather than burning coal completely a partial combustion takes place in the presence of steam and limited amounts of oxygen. In this controlled environment, a chemical reaction takes place to produce a mixture of clean synthetic gas. Gas-solid fluidized bed is one such type of gasification technology. During gasification, the mixing behavior of solid (coal) and gas and their flow patterns can be very complicated to understand. Many attempts have taken place in laboratory scale to understand bed hydrodynamics with spherical particles though in actual applications with coal, the particles are non-spherical. This issue drove the documented attempt presented here to investigate fluidized bed behavior using different ranges of non-spherical particles, as well as spherical. For this investigation, various parameters are controlled that included particle size, bed height, bed diameter and particle shape. Particles ranged from 355 µm to 1180 µm, bed diameter varied from 2 cm to 7 cm, two fluidized beds with diameters of 3.4 cm and 12.4 cm, for the spherical and non-spherical shaped particles that were taken into consideration. Pressure drop was measured with increasing superficial gas velocity. The velocity required in order to start to fluidize the particle is called the minimum fluidization velocity, which is one of the most important parameters to design and optimize within a gas-solid fluidized bed. This minimum fluidization velocity was monitored during investigation while observing variables factors and their effect on this velocity. From our investigation, it has been found that minimum fluidization velocity is independent of bed height for both spherical and non-spherical particles. Further, it decrease with decreasing particle size and decreases with decreasing bed diameter. Shadow sizing, a non-intrusive imaging and diagnostic technology, was also used to visualize flow fields inside fluidized beds for both spherical and non- spherical particles and to detect the particle sizes.

  18. Analysis/control of in-bed tube erosion phenomena in the fluidized bed combustion (FBC) system. Quarterly report

    SciTech Connect (OSTI)

    Lee, Seong W.

    1996-01-01

    This technical report summarizes the research work performed and progress achieved during the period of October 1, 1995 to December 31, 1995. A series of material wastage tests was carried out on cooled AISI 1018 steel and three thermal-sprayed coating specimens at an elevated environmental temperature (3000{degrees}C) using a nozzle type erosion tester. Test conditions simulated the erosion conditions at the in-bed tubes of fluidized combustors (FBCs). Angular silica quartz particles of average size 742 {micro}m were used for erodent particles for tests at an impact angle of 30{degrees}, at a particle velocity of 2.5 m/s for exposure periods up to 96 hours. The specimens were water-cooled on backside. Material wastage rates were determined from thickness loss measurements of specimens. Test results were compared with material wastage test results from testing isothermal specimens. The morphology of specimens was examined by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). It was found that the cooled specimens had greater material wastage than that of the isothermal specimens. The material wastage rate of cooling specimen for AISI 1018 was greater than that for thermal- sprayed coatings. The success in reduction of erosion wastage by cooled-coating specimens was related to the coatings, composition and morphology.

  19. Biologically Effective Dose (BED) Correlation With Biochemical Control After Low-Dose Rate Prostate Brachytherapy for Clinically Low-Risk Prostate Cancer

    SciTech Connect (OSTI)

    Miles, Edward F.; Nelson, John W.; Alkaissi, Ali K.; Das, Shiva; Clough, Robert W.; Broadwater, Gloria; Anscher, Mitchell S.; Chino, Junzo P.; Oleson, James R.

    2010-05-01

    Purpose: To assess the correlation of postimplant dosimetric quantifiers with biochemical control of prostate cancer after low-dose rate brachytherapy. Methods and Materials: The biologically effective dose (BED), dose in Gray (Gy) to 90% of prostate (D{sub 90}), and percent volume of the prostate receiving 100% of the prescription dose (V{sub 100}) were calculated from the postimplant dose-volume histogram for 140 patients undergoing low-dose rate prostate brachytherapy from 1997 to 2003 at Durham Regional Hospital and the Durham VA Medical Center (Durham, NC). Results: The median follow-up was 50 months. There was a 7% biochemical failure rate (10 of 140), and 91% of patients (127 of 140) were alive at last clinical follow-up. The median BED was 148 Gy (range, 46-218 Gy). The median D{sub 90} was 139 Gy (range, 45-203 Gy). The median V{sub 100} was 85% (range, 44-100%). The overall 5-year biochemical relapse-free survival (bRFS) rate was 90.1%. On univariate Cox proportional hazards modeling, no pretreatment characteristic (Gleason score sum, age, baseline prostate-specific antigen, or clinical stage) was predictive of bRFS. The BED, D{sub 90}, and V{sub 100} were all highly correlated (Pearson coefficients >92%), and all were strongly correlated with bRFS. Using the Youden method, we identified the following cut points for predicting freedom from biochemical failure: D{sub 90} >= 110 Gy, V{sub 100} >= 74%, and BED >= 115 Gy. None of the covariates significantly predicted overall survival. Conclusions: We observed significant correlation between BED, D{sub 90}, and V{sub 100} with bRFS. The BED is at least as predictive of bRFS as D{sub 90} or V{sub 100}. Dosimetric quantifiers that account for heterogeneity in tumor location and dose distribution, tumor repopulation, and survival probability of tumor clonogens should be investigated.

  20. Deposition of carbonate mud beds within high-energy subtidal sand Dunes, Bahamas

    SciTech Connect (OSTI)

    Dill, R.F.; Steinen, R.P.

    1988-01-01

    Laminated, carbonate mud beds are being deposited in the interisland channels of the Exuma Cays in the Bahamas. They are associated with stromatolites and interbedded with ooid sands that form large migrating subtidal dunes on flood tidal deltas and bars. Currents up to 3 knots sweep in and out of the 4-8 m deep channels 3 hours out of every 6 hours, creating a high-energy bank margin environment not usually considered to be the site of mud-sized particle deposition. Mud deposits reach thicknesses of 1 m and have individual beds 2-5 cm thick. When exposed to flowing seawater, bed surfaces become encrusted with carbonate cement and algal mats. The white interior of mud beds between the crusts appears homogeneous, is soft, and has the consistency of ''tooth paste.'' Loose uncemented ooid sand is found above and below the mud beds, showing that both are occupying the same depositional environment. Rip-up clasts of the crusted mud beds, formed by scour of underlying sands, are carried throughout the channels and accumulate as a lag deposit within the troughs of migrating dunes. Some clasts are colonized by algal mats that trap ooid and skeletal sands forming stromatolite structures that can grow up to 2 m high.

  1. Development of algorithms for capacitance imaging techniques for fluidized bed flow fields

    SciTech Connect (OSTI)

    Loudin, W.J.

    1991-01-01

    The objective of this research is to provide support for the instrumentation concept of a High Resolution Capacitance Imaging System (HRCIS). The work involves the development and evaluation of the mathematical theory and associated models and algorithms which reduce the electronic measurements to valid physical characterizations. The research and development require the investigation of techniques to solve large systems of equations based on capacitance measurements for various electrode configurations in order to estimate densities of materials in a cross-section of a fluidized bed. Capacitance measurements are made for 400 connections of the 32-electrode system; 400 corresponding electric-field curves are constructed by solving a second order partial differential equation. These curves are used to partition the circular disk into 193 regions called pixels, and the density of material in each pixel is to be estimated. Two methods of approximating densities have been developed and consideration of a third method has been initiated. One method (Method 1) is based on products of displacement currents for intersecting electric-field curves on a cross section. For each pixel one point of intersection is chosen, and the product of the capacitance measurements is found. Both the product and the square-root-of-product seem to yield good relative distribution of densities.

  2. Development of algorithms for capacitance imaging techniques for fluidized bed flow fields. 1990 Annual report

    SciTech Connect (OSTI)

    Loudin, W.J.

    1991-01-01

    The objective of this research is to provide support for the instrumentation concept of a High Resolution Capacitance Imaging System (HRCIS). The work involves the development and evaluation of the mathematical theory and associated models and algorithms which reduce the electronic measurements to valid physical characterizations. The research and development require the investigation of techniques to solve large systems of equations based on capacitance measurements for various electrode configurations in order to estimate densities of materials in a cross-section of a fluidized bed. Capacitance measurements are made for 400 connections of the 32-electrode system; 400 corresponding electric-field curves are constructed by solving a second order partial differential equation. These curves are used to partition the circular disk into 193 regions called pixels, and the density of material in each pixel is to be estimated. Two methods of approximating densities have been developed and consideration of a third method has been initiated. One method (Method 1) is based on products of displacement currents for intersecting electric-field curves on a cross section. For each pixel one point of intersection is chosen, and the product of the capacitance measurements is found. Both the product and the square-root-of-product seem to yield good relative distribution of densities.

  3. Fixed bed reduction of hematite under alternating reduction and oxidation cycles

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Breault, Ronald W.; Monazam, Esmail R.

    2015-02-28

    The rate of the reduction reaction of a low cost natural hematite oxygen carrier for chemical looping combustion was investigated in a fixed bed reactor where hematite samples of about 1 kg were exposed to a flowing stream of methane and argon. The investigation aims to develop understanding of the factors that govern the rate of reduction with in larger reactors as compared to mostly TGA investigations in the literature. Comparison of the experimental data with a model indicated that reaction between the methane and the iron oxide shows multi-step reactions. The analysis also shows that the conversion occurs withmore »a process that likely consumes all the oxygen close to the surface of the hematite particles and another process that is likely controlled by the diffusion of oxygen to the surface of the particles. Additional analysis shows that the thickness of the fast layer is on the order of 8 unit crystals. This is about 0.4% of the hematite; however, it comprises about 20 to 25% of the conversion for the 10 min reduction cycle.« less

  4. Post-treatment of fly ash by ozone in a fixed bed reactor

    SciTech Connect (OSTI)

    Kim Hougaard Pedersen; Merc Casanovas Meli; Anker Degn Jensen; Kim Dam-Johansen

    2009-01-15

    The residual carbon in fly ash produced from pulverized coal combustion can adsorb the air-entraining admixtures (AEAs) added to enhance air entrainment in concrete. This behavior of the ash can be suppressed by exposing the fly ash to oxidizing species, which oxidizes the carbon surface and thus prevents the AEA to be adsorbed. In the present work, two fly ashes have been ozonated in a fixed bed reactor and the results showed that ozonation is a potential post-treatment method that can lower the AEA requirements of a fly ash up to 6 times. The kinetics of the carbon oxidation by ozone was found to be fast. A kinetic model has been formulated, describing the passivation of carbon, and it includes the stoichiometry of the ozone consumption (0.8 mol of O{sub 3}/kg of C) and an ineffective ozone loss caused by catalytic decomposition. The simulated results correlated well with the experimental data. 28 refs., 7 figs., 3 tabs.

  5. Enhanced durability of desulfurization sorbents for fluidized-bed applications

    SciTech Connect (OSTI)

    Gupta, R.P.; Gangwal, S.K.

    1992-11-01

    To extend the operating temperature range and further improve the durability of fluidizable sorbents, zinc titanate, another leading regenerable sorbent, was selected for development in the later part of this project. A number of zinc titanate formulations were prepared in the 50 to 300 [mu]m range using granulation and spray drying methods. Important sorbent preparation variables investigated included zinc to titanium ratio, binder type, binder amount, and various chemical additives such as cobalt and molybdenum. A number of sorbents selected on the basis of screening tests were subjected to bench-scale testing for 10 cycles at high temperature, high pressure (HTHP) conditions using the reactor system designed and constructed during the base program. This reactor system is capable of operation either as a 2.0 in. or 3.0 in. I.D. bubbling bed and is rated up to 20 atm operation at 871[degrees]C. Bench-scale testing variables included sorbent type, temperature (550 to 750[degrees]C), gas type (KRW or Texaco gasifier gas), steam content of coal gas, and fluidizing gas velocity (6 to 15 cm/s). The sorbents prepared by spray drying showed poor performance in terms of attrition resistance and chemical reactivity. On the other hand, the granulation method proved to be very successful. For example, a highly attrition-resistant zinc titanate formulation, ZT-4, prepared by granulation exhibited virtually no zinc loss and demonstrated a constant high reactivity and sulfur capacity over 10 cycles, i.e., approximately a 60 percent capacity utilization, with Texaco gas at 750[degrees]C, 15 cm/s fluidizing velocity and 15 atm pressure. The commercial potential of the granulation method for zinc titanate manufacture was demonstrated by preparing two 80 lb batches of sorbent with zinc to titanium mol ratios of 0.8 and 1.5.

  6. Nuclear Safeguards Considerations For The Pebble Bed Modular Reactor (PBMR)

    SciTech Connect (OSTI)

    Phillip Casey Durst; David Beddingfield; Brian Boyer; Robert Bean; Michael Collins; Michael Ehinger; David Hanks; David L. Moses; Lee Refalo

    2009-10-01

    High temperature reactors (HTRs) have been considered since the 1940s, and have been constructed and demonstrated in the United Kingdom (Dragon), United States (Peach Bottom and Fort Saint Vrain), Japan (HTTR), Germany (AVR and THTR-300), and have been the subject of conceptual studies in Russia (VGM). The attraction to these reactors is that they can use a variety of reactor fuels, including abundant thorium, which upon reprocessing of the spent fuel can produce fissile U-233. Hence, they could extend the stocks of available uranium, provided the fuel is reprocessed. Another attractive attribute is that HTRs typically operate at a much higher temperature than conventional light water reactors (LWRs), because of the use of pyrolytic carbon and silicon carbide coated (TRISO) fuel particles embedded in ceramic graphite. Rather than simply discharge most of the unused heat from the working fluid in the power plant to the environment, engineers have been designing reactors for 40 years to recover this heat and make it available for district heating or chemical conversion plants. Demonstrating high-temperature nuclear energy conversion was the purpose behind Fort Saint Vrain in the United States, THTR-300 in Germany, HTTR in Japan, and HTR-10 and HTR-PM, being built in China. This resulted in nuclear reactors at least 30% or more thermodynamically efficient than conventional LWRs, especially if the waste heat can be effectively utilized in chemical processing plants. A modern variant of high temperature reactors is the Pebble Bed Modular Reactor (PBMR). Originally developed in the United States and Germany, it is now being redesigned and marketed by the Republic of South Africa and China. The team examined historical high temperature and high temperature gas reactors (HTR and HTGR) and reviewed safeguards considerations for this reactor. The following is a preliminary report on this topic prepared under the ASA-100 Advanced Safeguards Project in support of the NNSA Next Generation Safeguards Initiative (NGSI).

  7. Enhanced durability of desulfurization sorbents for fluidized-bed applications

    SciTech Connect (OSTI)

    Gupta, R.P.; Gangwal, S.K.

    1992-11-01

    To extend the operating temperature range and further improve the durability of fluidizable sorbents, zinc titanate, another leading regenerable sorbent, was selected for development in the later part of this project. A number of zinc titanate formulations were prepared in the 50 to 300 {mu}m range using granulation and spray drying methods. Important sorbent preparation variables investigated included zinc to titanium ratio, binder type, binder amount, and various chemical additives such as cobalt and molybdenum. A number of sorbents selected on the basis of screening tests were subjected to bench-scale testing for 10 cycles at high temperature, high pressure (HTHP) conditions using the reactor system designed and constructed during the base program. This reactor system is capable of operation either as a 2.0 in. or 3.0 in. I.D. bubbling bed and is rated up to 20 atm operation at 871{degrees}C. Bench-scale testing variables included sorbent type, temperature (550 to 750{degrees}C), gas type (KRW or Texaco gasifier gas), steam content of coal gas, and fluidizing gas velocity (6 to 15 cm/s). The sorbents prepared by spray drying showed poor performance in terms of attrition resistance and chemical reactivity. On the other hand, the granulation method proved to be very successful. For example, a highly attrition-resistant zinc titanate formulation, ZT-4, prepared by granulation exhibited virtually no zinc loss and demonstrated a constant high reactivity and sulfur capacity over 10 cycles, i.e., approximately a 60 percent capacity utilization, with Texaco gas at 750{degrees}C, 15 cm/s fluidizing velocity and 15 atm pressure. The commercial potential of the granulation method for zinc titanate manufacture was demonstrated by preparing two 80 lb batches of sorbent with zinc to titanium mol ratios of 0.8 and 1.5.

  8. Fluidized-bed retorting of Colorado oil shale: Topical report. [None

    SciTech Connect (OSTI)

    Albulescu, P.; Mazzella, G.

    1987-06-01

    In support of the research program in converting oil shale into useful forms of energy, the US Department of Energy is developing systems models of oil shale processing plants. These models will be used to project the most attractive combination of process alternatives and identify future direction for R and D efforts. With the objective of providing technical and economic input for such systems models, Foster Wheeler was contracted to develop conceptual designs and cost estimates for commercial scale processing plants to produce syncrude from oil shales via various routes. This topical report summarizes the conceptual design of an integrated oil shale processing plant based on fluidized bed retorting of Colorado oil shale. The plant has a nominal capacity of 50,000 barrels per operating day of syncrude product, derived from oil shale feed having a Fischer Assay of 30 gallons per ton. The scope of the plant encompasses a grassroots facility which receives run of the mine oil shale, delivers product oil to storage, and disposes of the processed spent shale. In addition to oil shale feed, the battery limits input includes raw water, electric power, and natural gas to support plant operations. Design of the individual processing units was based on non-confidential information derived from published literature sources and supplemented by input from selected process licensors. The integrated plant design is described in terms of the individual process units and plant support systems. The estimated total plant investment is similarly detailed by plant section and an estimate of the annual operating requirements and costs is provided. In addition, the process design assumptions and uncertainties are documented and recommendations for process alternatives, which could improve the overall plant economics, are discussed.

  9. P-wave re ections in 3-D model of coal basin with boulders (has been accepted for poster presentation at EAGE conference, Leipzig 1998)

    E-Print Network [OSTI]

    Cerveny, Vlastislav

    P-wave re ections in 3-D model of coal basin with boulders (has been accepted for poster to the computation of re ections in 3-D model of coal basin with four boulders located in the upper bed of the coal. Tselentis, pers. comm.). The model is composed of a low velocity layer, upper bed, four boulders, coal seam

  10. Sequestration and Enhanced Coal Bed Methane: Tanquary Farms Test Site, Wabash County, Illinois

    SciTech Connect (OSTI)

    Scott Frailey; Thomas Parris; James Damico; Roland Okwen; Ray McKaskle; Charles Monson; Jonathan Goodwin; E. Beck; Peter Berger; Robert Butsch; Damon Garner; John Grube; Keith Hackley; Jessica Hinton; Abbas Iranmanesh; Christopher Korose; Edward Mehnert; Charles Monson; William Roy; Steven Sargent; Bracken Wimmer

    2012-05-01

    The Midwest Geological Sequestration Consortium (MGSC) carried out a pilot project to test storage of carbon dioxide (CO{sub 2}) in the Springfield Coal Member of the Carbondale Formation (Pennsylvanian System), in order to gauge the potential for large-scale CO{sub 2} sequestration and/or enhanced coal bed methane recovery from Illinois Basin coal beds. The pilot was conducted at the Tanquary Farms site in Wabash County, southeastern Illinois. A four-well designâ?? an injection well and three monitoring wellsâ??was developed and implemented, based on numerical modeling and permeability estimates from literature and field data. Coal cores were taken during the drilling process and were characterized in detail in the lab. Adsorption isotherms indicated that at least three molecules of CO{sub 2} can be stored for each displaced methane (CH{sub 4}) molecule. Microporosity contributes significantly to total porosity. Coal characteristics that affect sequestration potential vary laterally between wells at the site and vertically within a given seam, highlighting the importance of thorough characterization of injection site coals to best predict CO{sub 2} storage capacity. Injection of CO{sub 2} gas took place from June 25, 2008, to January 13, 2009. A â??continuousâ?ť injection period ran from July 21, 2008, to December 23, 2008, but injection was suspended several times during this period due to equipment failures and other interruptions. Injection equipment and procedures were adjusted in response to these problems. Approximately 92.3 tonnes (101.7 tons) of CO{sub 2} were injected over the duration of the project, at an average rate of 0.93 tonne (1.02 tons) per day, and a mode injection rate of 0.6â??0.7 tonne/day (0.66â??0.77 ton/day). A Monitoring, Verification, and Accounting (MVA) program was set up to detect CO{sub 2 leakage. Atmospheric CO{sub 2} levels were monitored as were indirect indicators of CO{sub 2} leakage such as plant stress, changes in gas composition at wellheads, and changes in several shallow groundwater characteristics (e.g., alkalinity, pH, oxygen content, dissolved solids, mineral saturation indices, and isotopic distribution). Results showed that there was no CO{sub 2} leakage into groundwater or CO{sub 2} escape at the surface. Post-injection cased hole well log analyses supported this conclusion. Numerical and analytical modeling achieved a relatively good match with observed field data. Based on the model results the plume was estimated to extend 152 m (500 ft) in the face cleat direction and 54.9 m (180 ft) in the butt cleat direction. Using the calibrated model, additional injection scenariosâ??injection and production with an inverted five-spot pattern and a line drive patternâ??could yield CH{sub 4} recovery of up to 70%.

  11. Is it appropriate to model turbidity currents with the Three-Equation Model?

    E-Print Network [OSTI]

    Hu, Peng; He, Zhiguo

    2015-01-01

    The Three-Equation Model (TEM) was developed in the 1980s to model turbidity currents (TCs) and has been widely used ever since. However, its physical justification was questioned because self-accelerating TCs simulated with the steady TEM seemed to violate the turbulent kinetic energy balance. This violation was considered as a result of very strong sediment erosion that consumes more turbulent kinetic energy than is produced. To confine bed erosion and thus remedy this issue, the Four-Equation Model (FEM) was introduced by assuming a proportionality between the bed shear stress and the turbulent kinetic energy. Here we analytically proof that self-accelerating TCs simulated with the original steady TEM actually never violate the turbulent kinetic energy balance, provided that the bed drag coefficient is not unrealistically low. We find that stronger bed erosion, surprisingly, leads to more production of turbulent kinetic energy due to conversion of potential energy of eroded material into kinetic energy of ...

  12. SCIAMACHY'S ABSORBING AEROSOL INDEX AND THE CONSEQUENCES OF INSTRUMENT DEGRADATION

    E-Print Network [OSTI]

    Graaf, Martin de

    SCIAMACHY'S ABSORBING AEROSOL INDEX AND THE CONSEQUENCES OF INSTRUMENT DEGRADATION L. G. Tilstra1- itoring the Absorbing Aerosol Index (AAI) [1] measured by the satellite instrument SCIAMACHY [2]. We find. This we conclude from straightforward calculation of the effect of instrument degradation based

  13. Ecological consequences of early Late Pleistocene megadroughts in tropical Africa

    E-Print Network [OSTI]

    Reiners, Peter W.

    Ecological consequences of early Late Pleistocene megadroughts in tropical Africa Andrew S. Cohen conditions in tropical Africa occurred in several discrete episodes between 135 and 90 ka, as demonstrated]. This resulted in extraordinarily low lake levels, even in Africa's deepest lakes. On the basis of well dated

  14. Thermodynamics and Relativity: Possible Consequences of their Close Link

    E-Print Network [OSTI]

    Jean-Louis Tane

    2008-05-25

    The first part of this paper is a summary of a hypothesis previously advanced, suggesting the existence of a close link between thermodynamics and relativity. The second part is a preliminary comment about some possible consequences in the fields of physics, astronomy and biology.

  15. Consequences of Fault Currents Contributed by Distributed Generation

    E-Print Network [OSTI]

    the system Zbus matrix. The effects of merchant plants, such as Independent Power Producers, are not taken Power Systems Engineering Research Center A National Science Foundation Industry/University Cooperative Research Center since 1996 PSERC #12;Power Systems Engineering Research Center Consequences of Fault

  16. Causes and Consequences of Corruption Dr. Bonnie Palifka

    E-Print Network [OSTI]

    Post, David M.

    -Ackerman, Susan. 1999. Corruption and Government: Causes, Consequences, and Reform. Cambridge: Cambridge of Economic Issues XLI,4: 1043-1061. How is corruption measured? Assignment: browse the websites of Transparency International (http://www.transparency.org/) and the World Bank (http://www1.worldbank

  17. Combustion of municipal solid wastes with oil shale in a circulating fluidized bed. Quarterly report, quarter ending 31 December 1994

    SciTech Connect (OSTI)

    Not Available

    1995-01-01

    The test plan is designed to demonstrate that oil shale co-combusted with municipal solid waste (MSW) can reduce gaseous pollutants (SO{sub 2}, CO) to acceptable levels (90%+ reduction) and produce a cementitious ash which will, at a minimum, be acceptable in normal land fills. The small-scale combustion testing will be accomplished in a 6-in. circulating fluid bed combustor (CFBC) at Hazen Research Laboratories. This work will be patterned after the study the authors conducted in 1988 when coal and oil shale were co-combusted in a program sponsored by the Electric Power Research Institute. The specific purpose of the test program will be to: determine the required ratio of oil shale to MSW by determining the ratio of absorbent to pollutant (A/P); determine the effect of temperature and resident time in the reactor; and determine if kinetic model developed for coal/oil shale mixture is applicable.

  18. Causes and Consequences of Parasitism in the California Fiddler Crab, Uca crenulata

    E-Print Network [OSTI]

    Mora, Adrienne Brooke

    2013-01-01

    and A.F. Read. 2005. Evolutionary causes and consequences ofCALIFORNIA RIVERSIDE Causes and Consequences of ParasitismOF THE DISSERTATION Causes and Consequences of Parasitism in

  19. Moving granular-bed filter development program topical report. Base contract test plan

    SciTech Connect (OSTI)

    Newby, R.A.; Dilmore, W.J.; Fellers, A.W.; Gasparovic, A.C.; Kittle, W.F.; Lippert, T.E.; Smeltzer, E.E.; Yang, W.C.

    1991-10-17

    The Westinghouse Science & Technology Center has proposed a novel moving granular-bed filter concept, the Standleg Moving Granular-Bed Filter (S-MGBF) system, that overcomes the inherent deficiencies of the current state-of-the-art moving granular-bed filter technology. The S-MGBF system combines two unique features that make it highly effective for use in advanced coal-fueled power plants. First, the S-MGBF system applies pelletization technology to generate filter pellets from the power plant solid waste materials, and uses these pellets as a ``once-through`` filtering media to eliminate the need for costly, complex, and large filter media recycling equipment. This pelletizing step also generates a more environmentally acceptable solid waste product and provides the potential to incorporate gas-phase contaminant sorbents into the filtering media. Secondly, the S-MGBF system passes these pellets and the flyash laden power plant gas through a highly compact S-MGBF that uses cocurrent gas-pellet contacting in an arrangement that greatly simplifies and enhances the distribution of dirty gas to the moving bed and the disengagement of clean gas from the moving bed.

  20. Bulk chemical and Hfâ??W isotopic consequences of incomplete accretion during planet formation

    E-Print Network [OSTI]

    Dwyer, Christina A; Nimmo, Francis; Chambers, John E

    2015-01-01

    Bulk chemical and Hf–W isotopic consequences of incompletestyle affects the bulk chemical and isotopic outcomes ofto investigate the bulk chemical and isotopic consequences

  1. The Consequences of Strategic Alliances Between International Airlines: The Case of Swissair and SAS

    E-Print Network [OSTI]

    Youssef, Waleed; Hansen, Mark

    1993-01-01

    Intemationai Airline Equity_ Alliances, Ph.D. Disse~aation,Consequences of Strategic Alliances Between InternationalThe Consequences Strategic Alliances BetweenInternational

  2. Causes and Consequences of Variation in Fern Leaf Form and Physiology

    E-Print Network [OSTI]

    Czerniak, Christine Fiona

    2013-01-01

    gradient: patterns and causes. Ecotropica (Bonn) 13: 27-43.new insights into the causes and consequences of variationCALIFORNIA Los Angeles Causes and Consequences of Variation

  3. STORAGE OF CHILLED NATURAL GAS IN BEDDED SALT STORAGE CAVERNS

    SciTech Connect (OSTI)

    JOel D. Dieland; Kirby D. Mellegard

    2001-11-01

    This report provides the results of a two-phase study that examines the economic and technical feasibility of converting a conventional natural gas storage facility in bedded salt into a refrigerated natural gas storage facility for the purpose of increasing the working gas capacity of the facility. The conceptual design used to evaluate this conversion is based on the design that was developed for the planned Avoca facility in Steuben County, New York. By decreasing the cavern storage temperature from 43 C to -29 C (110 F to -20 F), the working gas capacity of the facility can be increased by about 70 percent (from 1.2 x 10{sup 8} Nm{sup 3} or 4.4 billion cubic feet (Bcf) to 2.0 x 10{sup 8} Nm{sup 3} or 7.5 Bcf) while maintaining the original design minimum and maximum cavern pressures. In Phase I of the study, laboratory tests were conducted to determine the thermal conductivity of salt at low temperatures. Finite element heat transfer calculations were then made to determine the refrigeration loads required to maintain the caverns at a temperature of -29 C (-20 F). This was followed by a preliminary equipment design and a cost analysis for the converted facility. The capital cost of additional equipment and its installation required for refrigerated storage is estimated to be about $13,310,000 or $160 per thousand Nm{sup 3} ($4.29 per thousand cubic feet (Mcf)) of additional working gas capacity. The additional operating costs include maintenance refrigeration costs to maintain the cavern at -29 C (-20 F) and processing costs to condition the gas during injection and withdrawal. The maintenance refrigeration cost, based on the current energy cost of about $13.65 per megawatt-hour (MW-hr) ($4 per million British thermal units (MMBtu)), is expected to be about $316,000 after the first year and to decrease as the rock surrounding the cavern is cooled. After 10 years, the cost of maintenance refrigeration based on the $13.65 per MW-hr ($4 per MMBtu) energy cost is estimated to be $132,000. The gas processing costs are estimated to be $2.05 per thousand Nm{sup 3} ($0.055 per Mcf) of gas injected into and withdrawn from the facility based on the $13.65 per MW-hr ($4 per MMBtu) energy cost. In Phase II of the study, laboratory tests were conducted to determine mechanical properties of salt at low temperature. This was followed by thermomechanical finite element simulations to evaluate the structural stability of the cavern during refrigerated storage. The high thermal expansion coefficient of salt is expected to result in tensile stresses leading to tensile failure in the roof, walls, and floor of the cavern as it is cooled. Tensile fracturing of the cavern roof may result in loss of containment of the gas and/or loss of integrity of the casing shoe, deeming the conversion of this facility not technically feasible.

  4. Atmospheric fluidized bed combustion (AFBC) plants: an operations and maintenance study

    SciTech Connect (OSTI)

    Jack A. Fuller; Harvie Beavers; Robert Bessette [West Virginia University, Morgantown, WV (United States). College of Business and Economics

    2006-06-15

    The authors analyzed data from a fluidized bed boiler survey distributed during the spring of 2003 to develop appropriate AFBC (Atmospheric Fluidized Bed Combustion) performance benchmarks. The survey was sent to members of CIBO (Council of Industrial Boiler Owners), who sponsored the survey, as well as to other firms who had an operating AFBC boiler on-site. There were three primary purposes for the collection and analysis of the data contained in this fluidized bed boiler survey: (1) To develop AFBC benchmarks on technical, cost, revenue, and environmental issues; (2) to inform AFBC owners and operators of contemporary concerns and issues in the industry; (3) to improve decision making in the industry with respect to current and future plant start-ups and ongoing operations.

  5. Experimental Evaluation of Latent Variable Models for Dimensionality Reduction 

    E-Print Network [OSTI]

    Carreira-Perpinan, Miguel A; Renals, Steve

    1998-01-01

    We use electropalatographic (EPG) data as a test bed for dimensionality reduction methods based in latent variable modelling, in which an underlying lower dimension representation is inferred directly from the data. Several ...

  6. Probalistic Criticality Consequence Evaluation (SCPB:N/A)

    SciTech Connect (OSTI)

    P. Gottlieb; J.W. Davis; J.R. Massari

    1996-09-04

    This analysis is prepared by the Mined Geologic Disposal System (MGDS) Waste Package Development (WPD) department with the objective of providing a comprehensive, conservative estimate of the consequences of the criticality which could possibly occur as the result of commercial spent nuclear fuel emplaced in the underground repository at Yucca Mountain. The consequences of criticality are measured principally in terms of the resulting changes in radionuclide inventory as a function of the power level and duration of the criticality. The purpose of this analysis is to extend the prior estimates of increased radionuclide inventory (Refs. 5.52 and 5.54), for both internal and external criticality. This analysis, and similar estimates and refinements to be completed before the end of fiscal year 1997, will be provided as input to Total System Performance Assessment-Viability Assessment (TSPA-VA) to demonstrate compliance with the repository performance objectives.

  7. Research on the pyrolysis of hardwood in an entrained bed process development unit

    SciTech Connect (OSTI)

    Kovac, R.J.; Gorton, C.W.; Knight, J.A.; Newman, C.J.; O'Neil, D.J. . Research Inst.)

    1991-08-01

    An atmospheric flash pyrolysis process, the Georgia Tech Entrained Flow Pyrolysis Process, for the production of liquid biofuels from oak hardwood is described. The development of the process began with bench-scale studies and a conceptual design in the 1978--1981 timeframe. Its development and successful demonstration through research on the pyrolysis of hardwood in an entrained bed process development unit (PDU), in the period of 1982--1989, is presented. Oil yields (dry basis) up to 60% were achieved in the 1.5 ton-per-day PDU, far exceeding the initial target/forecast of 40% oil yields. Experimental data, based on over forty runs under steady-state conditions, supported by material and energy balances of near-100% closures, have been used to establish a process model which indicates that oil yields well in excess of 60% (dry basis) can be achieved in a commercial reactor. Experimental results demonstrate a gross product thermal efficiency of 94% and a net product thermal efficiency of 72% or more; the highest values yet achieved with a large-scale biomass liquefaction process. A conceptual manufacturing process and an economic analysis for liquid biofuel production at 60% oil yield from a 200-TPD commercial plant is reported. The plant appears to be profitable at contemporary fuel costs of $21/barrel oil-equivalent. Total capital investment is estimated at under $2.5 million. A rate-of-return on investment of 39.4% and a pay-out period of 2.1 years has been estimated. The manufacturing cost of the combustible pyrolysis oil is $2.70 per gigajoule. 20 figs., 87 tabs.

  8. Exploratory and basic fluidized-bed combustion studies. Quarterly report, January-March 1980

    SciTech Connect (OSTI)

    Johnson, I.; Myles, K.M.; Swift, W.M.

    1980-12-01

    This work supports development studies for both atmospheric and pressurized fluidized-bed coal combustion. Laboratory and process development studies are aimed at providing needed information on limestone utilization, removal of particulates and alkali metal compounds from the flue gas, control of SO/sub 2/ and trace pollutants emissions, and other aspects of fluidized-bed combustion. This report presents information on: (1) the development of a limestone utilization predictive methodology, (2) studies of particle breakup and elutriation, (3) basic studies on limestone sulfation enhancement by hydration, (4) studies of the kinetics of the hydration process, and (5) an investigation of various hydration process concepts.

  9. Under consideration for publication in J. Fluid Mech. 1 Erosion of a granular bed driven

    E-Print Network [OSTI]

    Kudrolli, Arshad

    relating some #12;Bed Erosion by Laminar Flow 3 measure of the fluid forcing at the onset of granular flowUnder consideration for publication in J. Fluid Mech. 1 Erosion of a granular bed driven by laminar fluid flow By A L E X A N D E R E. L O B K O V S K Y1, A S H I S H V. O R P E2, R Y A N M O L L O Y2

  10. On the recovery of traveling water waves with vorticity from the pressure at the bed

    E-Print Network [OSTI]

    Vera Mikyoung Hur; Michael R. Livesay

    2015-10-08

    We propose higher-order approximation formulae recovering the surface elevation from the pressure at the bed and the background shear flow for small-amplitude Stokes and solitary water waves. They offer improvements over the pressure transfer function and the hydrostatic approximation. The formulae compare reasonably well with asymptotic approximations of the exact relation between the pressure at the bed and the surface wave in the zero vorticity case, but they incorporate the effects of vorticity through solutions of the Rayleigh equation. Several examples are discussed.

  11. Method and apparatus for gasifying with a fluidized bed gasifier having integrated pretreating facilities

    DOE Patents [OSTI]

    Rice, Louis F. (Arcadia, CA)

    1981-01-01

    An integral gasifier including a pretreater section and a gasifier section separated by a distribution grid is defined by a single vessel. The pretreater section pretreats coal or other carbon-containing material to be gasified to prevent caking and agglomeration of the coal in the gasifier. The level of the coal bed of the pretreater section and thus the holding or residence time in said bed is selectively regulated by the amount of pretreated coal which is lifted up a lift pipe into the gasifier section. Thus, the holding time in the pretreater section can be varied according to the amount of pretreat necessary for the particular coal to be gasified.

  12. On the recovery of traveling water waves with vorticity from the pressure at the bed

    E-Print Network [OSTI]

    Hur, Vera Mikyoung

    2015-01-01

    We propose higher-order approximation formulae recovering the surface elevation from the pressure at the bed and the background shear flow for small-amplitude Stokes and solitary water waves. They offer improvements over the pressure transfer function and the hydrostatic approximation. The formulae compare reasonably well with asymptotic approximations of the exact relation between the pressure at the bed and the surface wave in the zero vorticity case, but they incorporate the effects of vorticity through solutions of the Rayleigh equation. Several examples are discussed.

  13. A Fluidized Bed Chiller: A New Approach in Making Slush-Ice 

    E-Print Network [OSTI]

    Klaren, D. G.; Van Der Meer, J. S.

    1991-01-01

    stream_source_info ESL-IE-91-06-05.pdf.txt stream_content_type text/plain stream_size 29778 Content-Encoding ISO-8859-1 stream_name ESL-IE-91-06-05.pdf.txt Content-Type text/plain; charset=ISO-8859-1 A FLUIDIZED BED... CHILLER: A NEW APPROACH IN MAKING SLUSH-ICE Dr.Ir. D.G. Klaren M.Sc. Technical Director Gebr. Scheffers B.V. Schiedam, The Netherlands ABSTRACT A fluidized bed heat exchanger already successfully applied for heat transfer applications involving...

  14. NEUTRINO SPECTRA FROM ACCRETION DISKS: NEUTRINO GENERAL RELATIVISTIC EFFECTS AND THE CONSEQUENCES FOR NUCLEOSYNTHESIS

    SciTech Connect (OSTI)

    Caballero, O. L.; McLaughlin, G. C. [Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States); Surman, R., E-mail: lcaballe@uw.edu, E-mail: olcaball@ncsu.edu, E-mail: gail_mclaughlin@ncsu.edu, E-mail: surmanr@union.edu [Department of Physics and Astronomy, Union College, Schenectady, NY 12308 (United States)

    2012-02-01

    Black hole (BH) accretion disks have been proposed as good candidates for a range of interesting nucleosynthesis, including the r-process. The presence of the BH influences the neutrino fluxes and affects the nucleosynthesis resulting from the interaction of the emitted neutrinos and hot outflowing material ejected from the disk. We study the impact of general relativistic effects on the neutrinos emitted from BH accretion disks. We present abundances obtained by considering null geodesics and energy shifts for two different disk models. We find that both the bending of the neutrino trajectories and the energy shifts have important consequences for the nucleosynthetic outcome.

  15. Neutrino Spectra from Accretion Disks: Neutrino General Relativistic Effects and the Consequences for Nucleosynthesis

    E-Print Network [OSTI]

    O. L Caballero; G. C. McLaughlin; R. Surman

    2011-05-31

    Black hole accretion disks have been proposed as good candidates for a range of interesting nucleosynthesis, including the r-process. The presence of the black hole influences the neutrino fluxes and affects the nucleosynthesis resulting from the interaction of the emitted neutrinos and hot outflowing material ejected from the disk. We study the impact of general relativistic effects on the neutrinos emitted from black hole accretion disks. We present abundances obtained by considering null geodesics and energy shifts for two different disk models. We find that both the bending of the neutrino trajectories and the energy shifts have important consequences for the nucleosynthetic outcome

  16. Conventional regression models Auto-generated units

    E-Print Network [OSTI]

    McCullagh, Peter

    Conventional regression models Auto-generated units Consequences of auto-generation Inference regression models Auto-generated units Consequences of auto-generation Inference and prediction Outline 1 Conventional regression models Gaussian models Binary regression model Properties of regression models Problems

  17. Mitigation of Severe Accident Consequences Using Inherent Safety Principles

    SciTech Connect (OSTI)

    R. A. Wigeland; J. E. Cahalan

    2009-12-01

    Sodium-cooled fast reactors are designed to have a high level of safety. Events of high probability of occurrence are typically handled without consequence through reliable engineering systems and good design practices. For accidents of lower probability, the initiating events are characterized by larger and more numerous challenges to the reactor system, such as failure of one or more major engineered systems and can also include a failure to scram the reactor in response. As the initiating conditions become more severe, they have the potential for creating serious consequences of potential safety significance, including fuel melting, fuel pin disruption and recriticality. If the progression of such accidents is not mitigated by design features of the reactor, energetic events and dispersal of radioactive materials may result. For severe accidents, there are several approaches that can be used to mitigate the consequences of such severe accident initiators, which typically include fuel pin failures and core disruption. One approach is to increase the reliability of the reactor protection system so that the probability of an ATWS event is reduced to less than 1 x 10-6 per reactor year, where larger accident consequences are allowed, meeting the U.S. NRC goal of relegating such accident consequences as core disruption to these extremely low probabilities. The main difficulty with this approach is to convincingly test and guarantee such increased reliability. Another approach is to increase the redundancy of the reactor scram system, which can also reduce the probability of an ATWS event to a frequency of less than 1 x 10-6 per reactor year or lower. The issues with this approach are more related to reactor core design, with the need for a greater number of control rod positions in the reactor core and the associated increase in complexity of the reactor protection system. A third approach is to use the inherent reactivity feedback that occurs in a fast reactor to automatically respond to the change in reactor conditions and to result in a benign response to these events. This approach has the advantage of being relatively simple to implement, and does not face the issue of reliability since only fundamental physical phenomena are used in a passive manner, not active engineered systems. However, the challenge is to present a convincing case that such passive means can be implemented and used. The purpose of this paper is to describe this third approach in detail, the technical basis and experimental validation for the approach, and the resulting reactor performance that can be achieved for ATWS events.

  18. Neutronic analysis of pebble-bed cores with transuranics 

    E-Print Network [OSTI]

    Pritchard, Megan Leigh

    2009-05-15

    in Microparticle Zones .................... 49 16 Energy Dependent Neutron Flux in Pebble Zones ............................... 50 17 Unit Cell Geometric Modifications for M/F Ratio Adjustments .......... 51 18 Spectral Variations in the Prototype... compositions based on spent LWR fuel. The objective of the research in this thesis is to: square4 Validate several models and various modeling techniques and capabilities 6 square4 Analyze configuration variation capabilities to achieve prolonged...

  19. An Agent-Based Test Bed for the Integrated Study of Retail and Wholesale Power System Operations

    E-Print Network [OSTI]

    Tesfatsion, Leigh

    with smart-grid functionality. The test bed will seam together two existing test beds, the AMES Wholesale and wholesale power sys- tem operation with smart-grid functionality. This project is innovative in three key of retail and wholesale power mar- kets operating over transmission and distribution grids with "smart-grid

  20. Abstract--Encouraged by previous performance of a hydraulic bed sensor, this work presents a new hydraulic transducer

    E-Print Network [OSTI]

    He, Zhihai "Henry"

    Abstract--Encouraged by previous performance of a hydraulic bed sensor, this work presents a new hydraulic transducer configuration which improves the system's ability to capture a heartbeat signal from. II.HYDRAULIC BED SENSOR A.Transducer construction The overall procedure and materials