The roller dryer is a kind of dryer machine, which can handle a large number of materials. Due to its reliable operation, operating flexibility, adaptability, large handling capacity, the dryer machine is widely used in metallurgy, building materials, food, light industry, chemical industry, coal, medicine ore industry. The rotary dryer is generally applicable to granular materials and it can also be used for the drying of some part of sticky pasty materials and the materials with high water content. The advantages of the dryer machine are that large production capacity, wide application range, low flow resistance, easy operation and the operation allows a larger change range.
The wet materials to be dried are transported to the hopper by belt conveyor or bucket elevator, and then enter the feeding end through the feeding hopper by passing through the feeder pipe. The slope of the feeding pipe should be greater than the natural inclination of the materials so that the material can inflow into the dryer machine smoothly. The dryer cylinder is a rotating cylinder which tiltes slightly into the horizontal. Adding materials from the higher end and the heat carrier enter from the low end, forming countercurrent contact with the material. The heat carrier and material can flow into the cylinder at the same time. With the rotation of the cylinder, the material move to the lower end by the role of gravity. In the process of moving forward of the wet materials in the cylinder body, the materials directly or indirectly get the heat of the heating medium so that the wet material is dried, and then the materials are sent by the belt conveyor or screw conveyor in the discharge end. In the wall of the cylinder body, it is equipped with a copy board, whose role is to lift the material up and scatter them to increase the contact surface between the material and the gas stream to improve the drying rate and promote the material to move forward.