Pyrometric temperature and size measurements of burning coal particles in a fluidized bed combustion reactor

The article reports on the application of fiber-optic two-color optical pyr ometry to the measurement of temperature and size of combusting coal partic les in an atmospheric fluidized bed combustion reactor. The utility of the measuring technique is that it makes possible nonintrusive in situ measurem ent of the dependence between the temperature and size of combusting fuel p articles. The method allows the temperatures of the fluidized bed and indiv idual fuel particles to be determined wherever these deviate from the bed t emperature. Besides giving these temperatures, this method also allows for the statistical determination of the particle size distribution within the population of observed particles. The effects of bed temperature (1130-1200 K) and oxygen concentration (5-8 vol%) on the temperature of combusting We sterholt high volatile bituminous coal particles were studied in a laborato ry-scale bubbling fluidized bed combustor. The average particle temperature exceeded the bed temperature by about 100-200 K,while the maximum particle temperatures were nearly 600 K above the bed temperature. The interrelatio n between the size (< 1.2 mm) and temperature of burning coal particles is presented. (C) 1999 by The Combustion Institute.