Physical and chemical transformations during pulverized coal combustion -- optical systems for measurements
- Sandia National Labs., Combustion Research Facility, Livermore, CA (US)
- Physics Dept. New Mexico State Univ., Las Cruces, NM (US)
One of the most difficult problems in developing diagnostic methods for coal combustion research is that of determining the composition of entrained coal, char, and mineral matter particles in the combustion zone. The authors have employed two laser-based techniques for the simultaneous measurement of the size, velocity, and elemental composition of particles in combustion flows. Laser spark spectroscopy, also called laser induced breakdown spectroscopy (LIBS), is used to determine the elemental composition of coal particles. Sizing measurements are done using two-color laser light scattering. Laser spark spectroscopy is a variation of conventional emission spectroscopy which uses a focused pulsed laser beam to generate an optical breakdown, commonly called a laser spark or a laser induced plasma. The origin and uses of this technique are well summarized. Many of its properties are similar to those of conventional arc or spark plasmas as discussed in standard texts on spectrochemistry. As with conventional techniques, the laser spark allows simultaneous multi-element detection. An important advantage is the ability to obtain information in hostile environments, in situ, where electrodes cannot be introduced. Two principal applications for this technique are proposed. The first is the simultaneous measurement of size, velocity, and composition of single particles and is primarily an analytical research tool for coal combustion studies. The second is the measurement of bulk properties before, during and after combustion by coaddition of hundreds or thousands of individual spectra. This can be envisioned as an on-line monitor in an operating combustor. The authors' experiments have elucidated the advantages and difficulties which will be encountered in these applications.
- OSTI ID:
- 6505438
- Report Number(s):
- CONF-8806136-
- Journal Information:
- Am. Chem. Soc., Div. Gas Fuel Chem., Prepr.; (United States), Journal Name: Am. Chem. Soc., Div. Gas Fuel Chem., Prepr.; (United States) Vol. 33:2; ISSN ACGPA
- Country of Publication:
- United States
- Language:
- English
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42 ENGINEERING
421000 -- Engineering-- Combustion Systems
CARBONACEOUS MATERIALS
CHEMICAL COMPOSITION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COAL
COMBUSTION
COMBUSTION PROPERTIES
COMBUSTORS
DATA
DIAGNOSTIC TECHNIQUES
ENERGY SOURCES
EXPERIMENTAL DATA
FLUIDIZED-BED COMBUSTORS
FOSSIL FUELS
FUELS
INFORMATION
KINETICS
LASER-PRODUCED PLASMA
MATERIALS
NUMERICAL DATA
ON-LINE MEASUREMENT SYSTEMS
ON-LINE SYSTEMS
OPTICAL PROPERTIES
OXIDATION
PARTICLE SIZE
PARTICLES
PARTICULATES
PHYSICAL PROPERTIES
PLASMA
PULVERIZED FUELS
REACTION KINETICS
SIZE
SPECTROSCOPY
THERMOCHEMICAL PROCESSES
VELOCITY