Screw conveyors are widely used in various sectors of the national economy, such as the grain industry, building materials industry, chemical industry, machinery manufacturing industry, and transportation industry. Screw conveyors are mainly used to convey various powdery, granular, and small block materials. The bulk materials conveyed include grains, beans, flour and other grain products, cement, clay, sand and other building materials, salts, alkalis, fertilizers and other chemicals, as well as coal, coke, ore and other bulk cargo. Screw conveyors are not suitable for conveying perishable, sticky, large-block and easy-to-agglomerate materials. In addition to conveying bulk materials, screw conveyors can also be used to transport various pieced items. Screw conveyors can complete mixing, stirring, cooling and other operations while conveying materials. In ports, screw conveyors are mainly used for unloading and unloading operations and horizontal and vertical transportation of bulk materials in warehouses. The screw unloader, which uses a horizontal screw shaft in direct contact with the material to unload the material layer by layer from both sides of the carriage, has been successfully used for many years in domestic ports. The screw ship unloader, which consists of a horizontal screw conveyor, a vertical screw conveyor and a relative screw reclaimer, has become a relatively advanced continuous ship unloading machine and is increasingly widely used in bulk cargo terminals at home and abroad.