ES8402064A1 - Cleaning flue gases to remove sulphur di:oxide - Google Patents

Abstract

Flue gases from heating plants, such as oil burners, are cleared by firstly removing solid particles and then removing N oxides and SO2 by passing through an aq. liq. spray and a heat exchanger in which the temp. of the flue gas is reduced to about 20-30 deg. C.. The gases are passed through a film of an alkaline liq., e.g. milk of lime or chloride of lime, through a second aq. liq. spray and finally through a H2SO4 neutralising liq. prior to exhaust to the atmos. or to an additional neutralising device. - There is no reduction of the amt. of SO2 of 98-100% while the flue gases are simultaneously cooled almost to room temp.. EPAB- EP--68006 B A process for cleaning flue gases from heating plants, such as oil burners, before their injection to the atmos. said flue gas contg. as impurities, besides solid particles such as fly ash, nitrogen oxides and sulphur oxides, said process comprising the steps of (a) removing solid particles from the flue gas; (b) passing said flue gas through a first shower of aq. liq.; and (c) passing said flue gas through a second shower of aq. liq., this liw. being emitted in a direction opposite the flow direction of the flue gas, characterised in that the liq. of the first shower is emitted intermittently, and between the steps (b) and (c) above, the temp. of said flue gas is reduced to between 20 and 30 deg. C by passing said flue gas through a heat exchanger in which the flue gas does not directly contact a heat exchanger fluid (=step d). (6pp) GBAB- GB2104885 B A process of cleaning flue gases in which after removal of any solid particles present the gases are cooled to a temperature in the range 20-30 deg. C by passage downward through a heat exchanger, the gases before entering the heat exchanger being passed downward through an intermittent first rain of aqueous liquid which falls on the heat exchanger and after the heat exchanger being washed by a second rain of aqueous liquid and then passed through a neutralizing device.e USAB- US4562053 A A method of cleaning flue gases from heating plants by initially removing coarse particles and then passing the gas through intermittent showers of aq. liq. - After washing the gases pass to a heat exchanger which reduces the flue gas temp. to 20-30 deg.C while the liq. present in the gas washes the heat exchanger surfaces. - The gas then passes on to a further spray washing zone before entering a sulphuric acid neutralisation liq. The cleaned gas is then discharged. Pref. the gases are washed with a mixt. of water and hydrogen peroxide.