Rotary dryer is widely used for drying slag limestone, coal powder, slag, clay, etc. It can also be used in building materials, metallurgy, chemical and cement industry. The rotary dryer mainly consists of dryer body, raw material feeding plate, driving and supporting device, seal ring, etc. It can be generally divided into four types, they are: rotary dryer, triple-drum dryer, indirect heat transfer dryer, vertical dryer. Different kind of dryer has its own characters and advantages, the specific choice of a special dryer depends on differents elements

Rotary dryer working principle

The rotary dryer is made up of a large, rotating cylindrical tube, usually supported by columns. The dryer slopes slightly so that the discharge end is lower than the material feed end in order to convey the material through the dryer. Material to be dried enters the dryer, and as the dryer rotates, the material is lifted up by a series of internal fins lining the inner wall of the dryer.

When the material gets high enough to roll back off the fins, it falls back down to the bottom of the dryer, passing through the hot gas stream as it falls. This gas stream can either be moving toward the discharge end from the feed end (known as co-current flow), or toward the feed end from the discharge end (known as counter-current flow).

The gas stream can be made up of a mixture of air and combustion gases from a burner, in which case the dryer is called a direct heated dryer. Alternatively, the gas stream may consist of air or another (sometimes inert) gas that is preheated. When the gas stream is preheated by some means where burner combustion gases do not enter the dryer, the dryer known as an indirect-heated type.

Rotary Dryer technical parameters

 

Rotary dryer from Jinma clients' site