Screw conveyor is such an equipment that rotate by the driving motor,to push materials so as to reach the conveying goals. It can transport horizontally, incline or vertical. Screw conveyor has simple structure, little lateral dimensions ,good sealing , easy to be closed and transporting , easy to operate as well as maintenance. From the types of screw conveyor ,it can divide into shafted screw conveyor and shaftless screw conveyor . In addition, shafted screw conveyor is available for transporting materials which are non-sticky ,dry and good flow. From the appearance,it can divide into U trough screw conveyor and tube screw conveyor.