... 2. Good seal performance, good transportation efficiency. Screw conveyor LSY type series spiral conveyor is a kind of new equipment with closed ... in block material, such as clay powder, pulverized coal, cement, sand, grain, small lumps, pebbles and cast iron chip, etc. ... piece material, which includes: clay powder, pulverized coal, cement, sand, grain, small piece of coal, cobble, and cast iron filings ...