METHOD AND EQUIPMENT FOR GASIFICATION AND BURNING OF SOLID WASTE

摘要

A method and equipment for gasification and burning of solid waste in which the solid waste is subjected to thermal decomposition and gasification at 450 DEG -650 DEG C in a fluidized bed of a fluidized bed gasification furnace, the resultant waste being subjected to melt combustion at 1200 DEG -1500 DEG C in a melt combustion furnace in a subsequent stage, whereby the ash is turned into fused slag. At least one of oxygen, vapor and air is selected as a gas supplied to the fluidized bed in the fluidized bed gasification furnace. The quantity of oxygen in the gas supplied to the fluidized bed is set to 10-30 % of a quantity of theoretical combustion oxygen. The following whirling movements of a fluidized medium are generated. The fluidized medium flows down as it is fluidized in a slow fluidized bed in a central portion of a furnace bottom, flows up as it is fluidized in an active fluidized bed in a peripheral portion of the furnace bottom, flows from a central portion to a peripheral portion in a lower portion of the fluidized bed and from a peripheral portion to a central portion in an upper portion of the fluidized bed as the fluidized medium is fluidized, and flows from a central portion to a peripheral portion in the lower portion of the fluidized bed as the fluidized medium is fluidized. The melt combustion furnace is of a whirling flow type.