The rotary dryer is a type of industrial dryer used to reduce or minimize the moisture content of the material it is handling by bringing it into contact with a heated gas. The dryer is made up of a rotating cylinder (“drum” or “shell”), a drive mechanism, and a support structure (commonly concrete posts or a steel frame). The cylinder is inclined slightly with the discharge end is lower than the material feed end so that material moves through the dryer under the influence of gravity. Material to be dried enters the dryer, and as the dryer rotates, the material is lifted up by a series of fins (known as flights) lining the inner wall of the dryer. When the material gets high enough, it falls back down to the bottom of the dryer, passing through the hot gas stream as it falls.