Compact structure, small cross sectional area, light weight, good sealed performance, high transmission efficiency, process arrangement flexible, installed, tear down, easy moving, and safe operation. Applicable to transport all kinds of powder, granular, small in block material, such as clay powder, pulverized coal, cement, sand, grain, small lumps, pebbles and cast iron chip, etc. Not suitable for conveying big viscosity, and easy to agglomerate, perishable materials.