wet material is sent to the hopper by belt conveyor or bucket elevator, and then the feeder through the hopper enters the feeding port through the feeding pipe. The inclination of the feeding pipe should be greater than the natural inclination of the material, so that the material can flow into the dryer smoothly. Rotary dryer adopts direct flow type of heating with heat soure from firing unit. The material to be dried is pushed back immediately by lifter board when enters the shell from feeding tank and feeding chute. Because the drier is installed in slope, material flows to the back end under gravity and rotation force, meanwhile, it is lifted by board repeatedly and thrown down accordingly, which make the material form even curtain, and exchange heat sufficiently with inner the heat flow. In the end, moisture one the surface and inner of the material is dried by repeatedly scattering.