UNIFORM FEEDING METHOD OF POWDER FUEL IN COMBUSTION FURNACE

PURPOSE:To provide the uniform distribution of a rate of reduction of nitrogen oxide and the volume of non-combustibles in an entire furnace by a method wherein powder fuel is fed from a pair of fuel injection ports in such a way as injected fuel flows are struck against each other. CONSTITUTION:In a triple-stage combustion method in a box-like vertical furnace, a secondary fuel is fed from a pair of upper and lower lateral injection ports 6 and 7. The upper injection port 6 is arranged at a front wall 8 in such a way as it may face forwardly and downwardly in an inclined orientation and the lower injection port 7 is slightly inclined in a forwardly and upwardly directed condition. Thus, fuel injection flows 9 and 10 fed from these injection ports 6 and 7 are struck to each other to form a cresent-shaped injection flow layer 11. In this way, the secondary fuel is fed to a specified position under a uniformly distributed condition. With this arrangement, it is possible to make a uniform rate of reduction of nitrogen oxide and a uniform distribution of non-combustioned substance in an entire furnace.