For various reasons, it is often desirable to increase retention time in the rotary kiln. In order to do this, the loading, or how much material is in the rotary kiln at one time, needs to be increased. This is done by adding what is called a “dam” to the interior of the rotary kiln.
A dam in a rotary kiln works much like a dam in a river. When a dam is put into place, material builds up behind the dam, forcing retention time to increase. Material then spills over the dam, and discharges from the rotary kiln (See Figure 1.). Internal dams can also be used if a discharge end dam is not sufficient.
Dams are useful when bed depth needs to be increased, or when retention time needs to be increased, using a rotary kiln that was designed for a particular retention time.
Dams are put in place when retention time needs to be increased using the same size rotary kiln. Dams allow the loading to be increased, which increases retention time by forcing the material to build up in the rotary kiln.
FEECO Rotary Kiln Series: