METHOD OF INCINERATING SLUDGE HAVING HIGH WATER CONTENT

PURPOSE:To keep operating temperature of a fulidized bed at a proper level in incinerating waste matter consisting of sludge having a high content of water and sludge having a low content of water in a fluidized-bed incinerator, by feeding the waste matter into the incinerator in the manner that only the sludge having a high water content is sprayed toward a free board area above the fluidized bed. CONSTITUTION:A furnace 1 is provided with an air inlet port 2 at a lower portion and a gas outlet port 3 at an upper portion, and a bottom plate 4 for supporting a fluidized bed 5 is provided with air nozzles 7 for feeding air introduced into a wind box 6 to the fluidized bed 5. Upwardly of the fluidized bed 5, there are formed a free board section 8 and an after-combustion chamber 9. Further, a nozzle 10 for spraying sludge having a high water content into the furnace is fixed to the wall of the furnace 1, in the manner that it extends through the furnace wall in the direction of the free board section 8. On the other hand, sludge having a low water content is stored in a separate feed tank 11 and ropped onto the fluidized bed 5 from an inlet port 13 by means of a feeder 12. With such an arrangement, it is enabled to keep the operating temperature of the fluidized bed 5 at a proper value and to thereby reduce consumption of auxiliary fuel and generation of Nox.