EXHAUST GAS TREATMENT DEVICE

摘要

PURPOSE:To surely prevent the corrosion in a heat exchanger and to decrease the dust concentration discharged into atmosphere by throwing again dust of relatively large particle size cut from a dust collection hopper on the upstream side of an electric precipitator into the upstream side of a heat exchanger. CONSTITUTION:In an exhaust gas treatment device, exhaust gas 2 contg. alkaline dust 7 discharged from a coal fired boiler 1 is given dust removal by an electric precipitator 6 and the exhaust gas 2 where dust has been removed is introduced into a wet desulfurizer 9 through a heat exchanger 8, Sulfur oxide 11 contained in the exhaust gas 2 is removed and simultaneously dust 7 remaining in the exhaust gas 2 is removed by the wet desulfurizer 9. The exhaust gas 2 delivered from the wet desulfurizer 9 exchanges heat with the exhaust gas 2 from the electric precipitator 6 through the heat exchanger 8 and then is discharged into atmosphere. And dust of relatively large particle size cut from a dust collection hopper 15 on the upstream side of the electric precipitator 6 is thrown again into the upstream side of the heat exchanger 8 from a dust rethrow-in line 18. Thus sulfuric acid formed in the heat exchanger 8 is neutralized by the dust 7.