Rotary Dryer

Working Principle

In the process of drying the material, the wet material is first sent to the hopper by the belt conveyor or bucket elevator. Then, through the feeding machine of the hopper, the material enters the feeding end through the feeding pipe. To ensure that the material can flow into the dryer smoothly, the inclination angle of the feeding pipe should be greater than the natural angle of repose of the material.

The cylinder of the rotary dryer is a rotating cylinder slightly inclined to the horizontal. The wet material is added from the higher end, and the heat carrier(heating medium) enters from the lower end, contacting the material in countercurrent flow. There is also the case where the heat carrier and the material flow into the cylinder in parallel. With the rotation of the drum of the rotary drum dryer equipment, the material moves to the lower end under the action of gravity.

When the wet material moves forward in the cylinder, it directly or indirectly receives heat from the heating medium, so that the wet material can be dried.The dried material is then sent out through the belt conveyor or screw conveyor at the discharge end.

There is a lifting flight(or copy board) on the inner wall of the drum dryer. Its function is to pick up and scatter the materials to increase the contact surface area between the materials and the airflow, so as to increase the drying rate and promote the advancement of the materials.

The heating medium of the tumble dryer is generally divided into hot air, flue gas,and so on. After the heating medium passes through the rotary drum dryer, a cyclone dust collector is generally required to capture the materials carried in the gas. If it is necessary to further reduce the dust content of the exhaust gas, it should be discharged after passing through a bag filter or a wet dust collector.