Rotary dryer is divided into many types, for example, limestone dryer, roller dryer, rotary drum dryer and spray dryer. Drying equipment is widely used in building materials, metallurgy, chemical industry and cement industry and is broadly applied to dry the materials such as limestone, coal powder, slag and clay.

Working principles of drying equipment:
The heat source of dryer drum is from combustion devices. This dryer drum adopts direct flow heating method. So the material should be sent to the shell by the feed chamber and feed chute. After that the material will be pushed backward by the spiral shoveling plate. As the rotary drum dryer is located with a tilt, the material flows to the end by the gravity. Meanwhile, it is shoveled repeatedly by the shoveling plate to the upper end then comes down constantly, forming an even curtain in the drum and exchanging heat fully with the hot current in the drum. With the material being raised and scattered again and again, the moisture is dried gradually. Finally it is dried totally.