The hot air enters the dryer from the hot blast stove while the materials enter from the hopper. The materials are raised by lifting blades inside the dryer and are dehydrated by the hot air. The materials are discharged from the dryer, while the hot air is taken away upwardly. The materials’ movement is based on the pushing power from the lifting blades. The rotary dryer cannot work independently. It needs cooperatively machines such as heat source (hot blast stove), air blower, cyclone and sometimes dust collecting equipment. This dryer is made of dryer body, hopper, discharge hole, gear ring and light ring.