To supply combustion exhaust gas as primary air by circulating it without delaying drying wastes.
A furnace upstream side wind box 17a of a rotary stoker type incinerator is provided with division wind boxes 31a, 31b, 31c, 31d, 31e and 31f in the upstream and downstream of the furnace. Exhaust gas re-circulation lines 37a, 37b, 37c, 37d, 37e and 37f with an exhaust gas supplying valve 38 are connected to branch lines 33a, 33b, 33c, 33d, 33e and 33f of an air supply line 33 connected to the division wind boxes 31a, 31b, 31c, 31d, 31e and 31f. Temperature distribution in upstream and downstream of the furnace in a drying zone 1a formed in an upstream side end of the furnace inside a rotary stoker main body 1 is measured, and combustion exhaust gas 36 is re-circulated in the only area, in which the waste 14 restricted in temperature change is dried at a constant ratio, to prevent the occurrence of influence for drying the waste 14 even if the hihg-humidity combustion exhaust gas 36 is re-circulated for supply.
MIZUNO MASAYUKI
TANAKA TAKAHIRO
YOKOMIZO HIROSHI
