Heat utilization system and the start-stop during the operation method and heat treatment system,

摘要

PPROBLEM TO BE SOLVED: To provide a heat utilization system which is equipped with a heat exchanger using dust-containing gas, the system preventing the occurrence of dust explosion and inflammation which occur due to the sedimentation of dust in the system, when the system starts or stops, and being excellent in safety by using existing equipment, to provide an operating method when the system starts or stops, and to provide a heat treatment system. PSOLUTION: The heat treatment system is provided with a direct heating-type dryer 1 which dries a material to be treated, a carbonization furnace 6 which carbonizes the dried material, a combustion furnace 11 which burns pyrolysis gas produced in the carbonization furnace 6, a heat exchanger 4 which heat-exchanges high-temperature combustion exhaust gas emitted from the combustion furnace 11 and low-temperature dried exhaust gas emitted from the drier 1, and an exhaust gas treatment line 5 which includes an acidic gas-removing device 52 for removing acidic gas from the combustion exhaust gas which passes through the heat exchanger 4 to be cooled. In this case, when the system starts or stops, at least a part of the combustion exhaust gas is branched from the downstream side of the acidic gas-removing device 52, and the gas, which is low in oxygen content and low in temperature, is introduced into the heat exchanger 4. PCOPYRIGHT: (C)2008,JPO&INPIT