Further Studies of the Combustion of Pulverized Char and Low- volatile Coal.
Demeter-JJ; McCann-CR; Bienstock-D
Pres Asme Ann Winter Mtg Detroit Michigan Nov 11-15 1973 Preprint 73-WA/FU2, 1973 Nov; :5 pages
Pulverized char was fired in a dry-bottom, front-wall-fired furnace, capable of burning about 500 lb of the material per hour. Earlier experiments with chars injected at ambient temperatures into this furnace had indicated that increasing amounts of supplementary fuel (natural gas) were required to maintain good combustion as the volatile matter of the char decreased with standardized conditions of burning rate, excess air, and primary air to fuel ratio. In the present investigation, the char-primary air mixture was preheated to eliminate the need for a dual fuel system. Effects of operating parameters such as secondary air preheat and fuel particle size were studied. A low-volatile (5-percent) char was burned successfully without supplemental fuel at a char preheat temperature of 450 deg - 500 deg f and a secondary air temperature of 600 deg f. A char preheat temperature of 550 deg f was required to obtain stable combustion without auxiliary fuel when the secondary air temperature was lowered to 500 deg f. Low-volatile (18 percent) Pocahontas coal could be burned in the experimental combustor without either auxiliary fuel or preheat of the coal, thus giving an indication of the order of difficulty in burning low-volatile char.
Pres. Asme Ann. Winter Mtg., Detroit, Michigan, Nov. 11-15, 1973, Preprint No. 73-WA/FU2