Circulating type fluidized bed combustion apparatus

Abstract

Distribution nozzles are arranged on an air distribution plate disposed at the lower portion of a furnace and spaced apart by a predetermined distance from the bottom thereof and one or more spouted nozzles extend upwardly from the air distribution plate so that not only a fluidized bed defined by the air discharged through the distribution nozzle but also one or more spouted beds defined by the air flows injected through the spouted nozzle or nozzles into the fluidized bed are formed within the furnace. Because of the coexistence of the fluidized bed and the spouted bed or beds, the agitated effect in the fluidized bed is enhanced and the combustion efficiency as well as the desulfurization can be pronounced. A particle feeding pipe is connected to the furnace to feed fuel and desulfurizing agent into the furnace. Secondary air from a secondary air supply pipe and portion of ash extracted through the bottom of the furnace by feed means are fed into the furnace at a position higher than the position of the opening of the particle feeding pipe into the furnace. A dust collector is disposed at a top of the furnace to circulate the ash trapped into the fluidized bed, whereby combustion efficiency as well as response to variations of load over a wide range can be ensured.