The screw conveyor is a major unit for industrial and agricultural departments mechanization transportation job,which can make the shipping work reduce the intensity of labor, improve work efficiency. It has a wide range of applications. Applicable to various industries, such as building materials, chemical industry, electric power, metallurgy, coal, food and other industries. Applicable to horizontal or oblique conveying powder, granulated and small lump materials, such as coal, ash, slag, cement, food, etc. The processed material temperature is less than 200 ℃. Screw machine is not suitable for transportation of perishable materials, big viscosity, easy to agglomerate material.