Powder selecting sealing device for improving fineness stability of raw materials

The utility model relates to the technical field of powder selecting machine sealing, in particular to a powder selecting sealing device capable of improving fineness stability of raw materials. According to the technical scheme, the powder concentrator comprises a first mounting frame, a second mounting frame, a powder concentrator body and a base, a first fixing rod and a supporting frame are welded to the top end face of the base, a fixing plate is welded to the inner wall of the supporting frame, and a through hole is formed in the fixing plate; a feeding pipe is fixedly embedded into the top end face of the powder concentrator body, and a fixing frame is welded to the top end face of the powder concentrator body. A second fixing rod and a second driving motor are installed on the inner wall of the fixing frame, and a second lead screw is welded to an output shaft of the second driving motor. A second limiting piece is welded to the bottom end face of the second mounting frame. A first driving motor is in