- Author
-
Whetstone, J. R.
|
Charagundla, S. R.
|
Macek, A.
|
Semerjian, H. G.
- Title
- Spectroscopic Combustion Temperature Measurements: Effect of Optical Depth in Black Liquor Recovery Boilers.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Journal
-
SPIE Industrial Optical Sensing,
Vol. 961,
78-84,
1988
- Keywords
-
spectroscopy
|
combustion
|
temperature measurements
|
boilers
|
emissions
|
potassium
|
emission spectra
|
absorption
|
pattern recognition
- Abstract
- Results of a study directed toward using observed spectroscopic features for the measurement of temperature in the combustion zone of recovery boilers are described. Emissions of the potassium doublets at 404 and 766 nanometers (nm) have been observed in recovery boilers and temperature and self absorption effects on lines shapes have been modeled. Predicted emission line shapes are strongly dependent upon predicted concentration values of potassium. Proper selection of concentration ranges results in good qualitative agreement of predicted line shapes with those observed in boilers and laboratory flame experiments. These results indicate that the temperature dependence of potassium emissions is complicated by self-absorption effects which limit the optical pathlength over which emissions are practically observable. Temperature measurement may be feasible using pattern recognition methods coupled with algorithms based on an emission model and realistic estimates of the emitting species concentration.