FLY ASH TREATMENT IN REFUSE INCINERATION EQUIPMENT AND DEVICE THEREFOR

摘要

PROBLEM TO BE SOLVED: To reduce the operating cost by adding hydroxide of alkali metal or alkaline earth metal or carbonate of alkali metal or alkaline earth metal to fly ash to lower the thermal decomposition temperature of dioxins and using a heat transfer medium to heat fly ash by exhaust heat from an incineration furnace and thermally decompose dioxins sufficiently and effectively. SOLUTION: In this device, fly ash collected from waste gas is agitated and heated with oxygen insufficient by a heater 16 and is held in that state for specified time and is quickly cooled by a cooler 17 to thermally decompose dioxins in the fly ash. In this case, hydroxide or carbonate of alkali metal or alkaline earth metal is added to the fly ash by a chemical adding device 15 to lower the thermal decomposition temperature of dioxins. The heating of the fly ash in the heater 16 is performed by a heating medium feeder 31 through a heating medium thermally recovered from a exhaust heat recovering device 2 of a refuse incineration furnace 1.