Spiral desulfurized fly ash return control device

The utility model relates to a desulfurized fly ash return device of a CFB (Circulating Fluidized Bed) semi-dry flue gas desulfurization system, in particular to a desulfurized fly ash spiral return control device, which comprises an ash bucket and an ash inlet flashboard door fixed at the bottom of the ash bucket, the material distribution fluidization box is fixed at the bottom of the ash inletflashboard door; the external ash discharge spiral feeding device comprises an external ash discharge spiral blade; an outer ash discharge spiral blade is rotationally arranged in the outer ash discharge spiral shell; the ash discharge screw driving device is fixed at the other end of the outer ash discharge spiral shell and is connected with one end of the outer ash discharge spiral blade; the circulating ash spiral feeding device comprises a circulating ash spiral blade; a circulating ash spiral blade is rotationally arranged in the circulating ash spiral shell; and the circulating ash screwdriving device is fixed a