Rotary dryers are slightly inclined cylindrical shells supported by 2 riding rings running on a set of rollers.
Rotary dryers are suitable for drying a wide range of materials because of their ability to process materials having considerable variation in size and composition.
A rotary dryer uses lifters mounted in the shell to produce a cascade of particles falling through a hot gas stream.
The mechanical lifting of the material allows rotary dryers to be used to dry materials ranging from fine filter cake to coarse minerals. It also helps in breaking up lumps, promoting a more uniformly dried material.
The proper design of a rotary dryer is based upon several key factors. The dryer diameter determines the gas
velocity. Lifter design determines how the material will fall through the gas stream. When designed correctly,
the full width of the dryer becomes a shower of material.
Chains may also be used when processing very wet material to improve heat transfer. Dryers are also designed for either parallel flow or counter flow.

The rotary dryer is a type of industrial dryer employed to reduce or minimize the liquid moisture content of the material it is handling by bringing it into direct contact with a heated gas. The dryer is made up of a large, rotating cylindrical tube, usually supported by concrete columns or steel beams. 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 under gravity. 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. Often, indirect heated dryers are used when product contamination is a concern.

Usage:
Suitable for screening flume waters.

Applications:
- Seafood processing - offal
- Pulp & Paper - rejects
- Meat & Poultry processing (offal and feathers)
- Potato processing - flume water