Rotary Dryer is used for dehumidify material with a certain moisture and granularity degree in concentrating, construction, and metallurgy and chemical plant. This machine adopts the downstream progress. It is easy to operate and maintain, satisfies various materials, can dry any kind of raw materials, as clay, coal, slag and ferrous powder etc and the bulk material in metallurgy and chemical industries. And dry the humidity from 15% to 6%. There are horizontal dryer and double drum dryer types. And we are researching for the three drum dryer. Horizontal is quite cheaper and is 18 meters long. The double drum dryer is about 8 meters long with low energy cost, more economic and less area covered features.