YLS overflow screw conveyor is a new type of screw conveyor, with an upward opening discharge port and a certain height overflow hopper. It relies on the compression of the opposite direction spiral blades at the discharge port to overflow the overflow hopper. Suitable for conveying and flow control of powdered and fine-grained materials. It has the characteristics of simple structure and good air locking performance, which can eliminate the need for rigid impeller feeders and other feeding equipment to be directly connected to the discharge port under the silo. Real time sealing and stabilizing effect.