Flue gas circulating fluidized bed desulfurization (CFB-FGD) technology was originally developed by Airbone in the United States in the 1980s, after years of digestion and absorption and operation improvement, semi-dry circulating bed desulfurization process has matured into another new desulphurization technology of our company。Flue gas circulating fluidized bed desulphurization system is mainly composed of absorbent preparation system, Venturi tube absorber, desulphurization dust collector, desulphurization ash circulation system and fluidized air system, process water spray system, compressed air system and control system。Its main features: 1.The process eliminates the lime pulping system of wet desulfurization and the slurry nozzles of the tower, and only sprays water mist and dry slaked lime powder。2.98% of the bed material in the desulfurization tower is involved in the cycle, and the cumulative residence time of the absorber in the absorption tower can reach more than 30min, so that the utilization rate of the absorber can reach more than 95%。3.The desulfurization efficiency of semi-dry method can reach more than 95-99%。4.The process is simplified, the infrastructure investment is relatively low, and the operation and maintenance amount is small, which overcomes the shortcomings of the effluent wastewater of wet desulfurization, does not need to set the desulfurization wastewater treatment device, and the flue gas operating temperature is above the dew point, which reduces the anti-corrosion requirements of the whole system。