After preliminary dust electrostatic precipitator from boiler flue gas by purification tower bottom through ventilation device into the purification tower. Atomized water by double fluid purification tower throat atomization nozzle spray into the purification tower, with a high mass transfer rate in the mixed with flue gas purification tower, flue gas of medium and small droplet and calcium oxide particles with a high mass transfer rate in flue gas SO ₂ acidic material such as mixed reaction, generate CaSO ₄ and CaSO ₃ reaction products, etc. These small dry products from purification tower bottom ash discharging mouth out, most of the flow separation and collection. After purification tower boiler flue gas desulfurization after purification, into the bag dust catcher system.
In order to improve the utilization and desulfurization efficiency of Ca ₂ +, this design set the desulfurization ash recirculation system, according to the concentration of the desulfurization ash in the reactor and the desulfurization efficiency to regulate the circulation ratio. Circulating ash from bag dust collector. Bag precipitator ash hopper ash by screw conveyor is divided into two road, a path star feeder into air chute echo to lower the venturi diffuser outlet purification tower, the rest of the ash pump via direct the other way by storehouse to ashes repository outside.