The flue gas produced in small boiler or industrial kiln, after the dust of which is preliminarily removed by the dust collector(cyclone dust collector or two-stage electric dust collector can be selected to save investment and operation cost) in the previous stage, is fed into the absorption tower by the induced draft fan for desulphurization and refined dust collection. Several layers of high-pressure water mist spray heads are placed in the tower. The spray head can spray out the high-pressure water mist containing desulphurizing agent. The SO2 and fine dust of the flue gas fully contact and react with the absorption solution and then fall on the tower bottom and flow into the ash water circulating system. The absorption solution, after absorbing the above substances, is regenerated with regenerating agent. The slurry precipitated is pumped into the slurry treatment system with slurry pump for concentration and filtering. The wet slurry obtained can be used as building accessories to be sold and conveyed outwards. While the filter liquor and precipitated supernatant liquor, after PH adjustment and water supplementation, is for cyclic utilization by the high pressure water mist pump to form closed circulation of ash water, which will not only avoid secondary pollution, but also reduce alkaliconsumption and operation cost. The flue gas after desulphurization and dust collection and reaching emission standardprovision will be discharged into the air from the chimney after its mist removed with high efficient mechanical mist eliminator.
The process flow is applicable for small coal-fired boiler, especially for those with capacity less than 35t/h. The front-mounting dry dust collector can conduct continuous reduction and removal for dry ash. The prophase dust collection efficiency is enough when reaching 70~80%. While the dust collection efficiency can be up to 99.5%, after refined dust collection in the desulphurization and dust collection tower. So it is especially applicable for non-ferrous smelting and iron and steel industries.
