Rotary dryer is a very wide range of drying equipment. The equipment in the original structure on the basis of a substantial breakthrough and innovation, the scope of application is more extensive. Mainly used in chemical industry, light industry, coal, building materials and mining industry occupies an important position. In recent years, rotary dryer has developed very rapidly. Medium-thickness mechanical rotary dryer in the design also appeared in many forms. The main performance of the three areas, namely: large-scale equipment specifications, structural diversity and energy saving and automation.