JPS6458902A - Fluidized-bed boiler - Google Patents

Abstract

PURPOSE:To make it possible to eliminate the temperature difference within the furnace and thus to make the temperature uniform by distributing coal fed from coal feed pipes and coal feed pipe nozzles at respective points on a diffusion plate of the fluidized-bed boiler at lesser amounts at furnace central part and more amounts at furnace wall part. CONSTITUTION:The distribution density of a large number of coal feed pipes on a diffusion plate is not set at a predetermined pitch but is set in such a manner that the pitch of arrangement is gradually reduced as represented by P0>P1>...>Pn from the furnace central part toward the furnace wall part. That is, the coal feed pipe nozzles are distributed sparsely at the furnace central part and densely toward the surroundings of the furnace wall part. Thereby, the amount of the fuel fed to the furnace central part where the temperature has been high is reduced, and the amount of the fuel to the vicinity of the furnace wall part where the temperature of the fluidized bed has been low. The temperature within the fluidized-bed is increased becomes uniform. In accordance with this, the overheating of the temperature of the metal of the pipes within the fluidized bed, such as a reheater 5, an overheater 6 or the like within the fluidized bed, can be prevented.