Physical and chemical transformations during pulverized coal combustion -- optical systems for measurements
- Sandia National Laboratories, Livermore, CA (USA)
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 experiments have elucidated the advantages and difficulties which will be encountered in these applications.
- OSTI ID:
- 5339133
- Report Number(s):
- CONF-8806316--
- Journal Information:
- Preprints of Papers, American Chemical Society, Division of Fuel Chemistry; (USA), Journal Name: Preprints of Papers, American Chemical Society, Division of Fuel Chemistry; (USA) Vol. 33:2; ISSN 0569-3772; ISSN ACFPA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
010600 -- Coal
Lignite
& Peat-- Properties & Composition
014000* -- Coal
Lignite
& Peat-- Combustion
CALIBRATION
CARBONACEOUS MATERIALS
CHARS
CHEMICAL COMPOSITION
CHEMICAL REACTION KINETICS
COAL
COMBUSTION KINETICS
DIAGRAMS
EMISSION SPECTROSCOPY
ENERGY SOURCES
ENTRAINMENT
FLOW RATE
FLOWSHEETS
FOSSIL FUELS
FUELS
KINETICS
LASER SPECTROSCOPY
LIGHT SCATTERING
MATERIALS
MINERALS
PARTICLE SIZE
PARTICLES
PERFORMANCE
PHASE STUDIES
PULVERIZED FUELS
PYROLYSIS PRODUCTS
REACTION KINETICS
SCATTERING
SIZE
SPECTROSCOPY