Screw conveyor is widely used in the grain industry, building materials industry, chemical industry, machinery manufacturing, transportation and other national economy departments. Spiral Conveyor is mainly used for conveying a variety of powdery, granular, small block materials, the delivery of granular materials have grains, beans, flour and other food products, cement, clay, sand and other building materials, salts, alkalis, fertilizers and other chemicals, as well as coal, coke, ore and other bulk goods. Screw conveyor is not suitable to transport perishable, viscous large, large and easily caking materials. In addition to conveying granular materials, can also use screw conveyor to transport a variety of items. The screw conveyor can complete mixing, stirring, cooling and other operations while conveying materials. In port, screw conveyor is mainly used for unloading, unloading operation and the horizontal and vertical conveying of bulk material in warehouse. Using the horizontal spiral shaft directly contacting the material, the screw unloading machine unloaded from both sides of the carriage has been successfully used in domestic ports for many years. The Spiral ship Unloader, which consists of horizontal screw conveyor, vertical screw conveyor and relative screw feeding device, has become a kind of advanced continuous ship unloading machine, which is widely used in the domestic and international bulk cargo wharf.