Pre-cooling recycling semi-dry process desulfurization dust-removing technique

The invention discloses a semi dry process desulfuration dedust craft of firstly pre-cooling and then circulation, in sequence comprising steps such as pre-cooling, acidity gas absorption, dust dedust, absorbent moistening recirculation. The invention has the advantages of firstly pre-cooling and then circulation desulfuration dedust of flue gas, reducing the addition of adding the circulation ash by back drop, improving the adding of the circulation ash and the working conditions of the moistening system, avoiding the phenomenon of shell clingage and fouling and nonuniform mixing produced by the adding of large amount of moistening water, reducing the running resistance of the system and the energy consumption in service, reducing the specific resistance of the dust in flue gas by pre-moistening the flue gas before desulfuration reaction, improving the dust collection efficiency, reducing the running load of the back drop dedusting equipment because of the great reducing of the dust into the back drop dedusting equipment (dust collector), and prolonging the service life of the dedusting equipment.