Mass and heat transfer in crushed oil shale
Heat and mass transfer between gases and oil-shale particles are both important for all proposed retorting processes. Past studies of transfer in packed beds, which have disagreed substantially in their results, have nearly all been done with beds of regular particles of uniform size, whereas oil-shale retorting involves particles of diverse shapes and widely ranging sizes. To resolve these questions, we have made 349 runs in which we measured mass-transfer rates from naphthalene particles of diverse shapes buried in packed beds through which air was passed at room temperature. This technique permits calculation of the mass-transfer coefficient for each active particle in the bed rather than, as in most past studies, for the bed as a whole. The data were analyzed in two ways: (1) by the traditional correlation of Colburn j/sub D/ vs Reynolds number and (2) by multiple regression of the mass-transfer coefficient on air rate, traditional correlation of Colburn j/sub D/ vs Reynolds number and (3) by multiple regression of the mass-transfer coefficient on air rate, sizes of active and inert particles, void fraction, and temperature. Principal findings are: (1) local Reynolds number should be based on active particle size rather than average size for the bed; (2) no appreciable differences were seen between shallow beds and deep ones; (3) mass transfer was 26% faster for spheres and lozenges buried in shale than for all-sphere beds; (4) orientation of lozenges in shale beds has little effect on mass-transfer rate; (5) a useful summarizing equation for either mass or heat transfer in shale beds is log j.epsilon = -.0747 - .6344 log Re + .0592 log/sup 2/Re where j = either j/sub D/ or j/sub H/, the Chilton-Colburn j-factors for mass and heat transfer, Re = the Reynolds number defined for packed beds, and epsilon = the void fraction in the bed. 12 references, 15 figures.
- Research Organization:
- Lawrence Livermore National Lab., CA (USA)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 6993867
- Report Number(s):
- UCRL-90221; CONF-8404121-7; ON: DE84012614
- Resource Relation:
- Conference: 17. oil shale symposium, Golden, CO, USA, 16 Apr 1984; Other Information: Portions are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
HEAT TRANSFER
MEASURING METHODS
MASS TRANSFER
NAPHTHALENE
OIL SHALES
CALCULATION METHODS
CRUSHING
EQUATIONS
EXPERIMENTAL DATA
AROMATICS
BITUMINOUS MATERIALS
CARBONACEOUS MATERIALS
COMMINUTION
CONDENSED AROMATICS
DATA
ENERGY SOURCES
ENERGY TRANSFER
FOSSIL FUELS
FUELS
HYDROCARBONS
INFORMATION
MATERIALS
NUMERICAL DATA
ORGANIC COMPOUNDS
040500* - Oil Shales & Tar Sands- Properties & Composition