EXHAUST GAS TREATING APPARATUS

摘要

An exhaust gas treating apparatus comprising, sequentially arranged from an upstream side to a downstream side of an exhaust gas duct of combustion unit , air preheater (3) for preheating air for combustion in a combustion unit wit h the use of exhaust gas discharged from the combustion unit; gas gas heater (GGH) heat recovering unit (4) composed of a bundle of heat transfer tubes f or recovering the heat of exhaust gas into heating medium; dust collector (5); wet type desulfurizer (7); and gas gas heater (GGH) reheating unit (8) composed of a bundle of heat transfer tubes for heating the exhaust gas from an outlet of the desulfurizer with the heating medium fed from the gas gas heater (GGH) heat recovering unit (4), wherein the heat transfer tube bundle of the heat recovering unit (4) is disposed in a square arrangement to the direction of gas flow so that the exhaust gas flow rate between adjacent hea t transfer tubes disposed at right angles to the direction of gas flow at the GGH heat recovering unit (4), inter-tube flow rate, is 10 m/s or below. The abrasion and corrosion of heat transfer tube bundle can be reduced even when the exhaust gas contains dust in high proportion.