Rotary drum dryer is drying equipment, widely used in mining. It is divided into direct heat rotary drum dryer and indirect heat rotary drum dryer. Rotary drum dryer is also known as roller dryer or cylinder dryer, which is the most common and widely used drying equipment in mining. It is suitable for the drying of magnetic, heavy mineral and floating concentrates of metal and non-metallic minerals, clay of cement industry and coal slime of coal industry etc. It is characterized by high productivity and easy operation.
Classification of the drum dryer: according to the mode of heat transfer between the drying medium and wet materials, it is divided into direct heat transfer rotary drum dryer (transferring heat with dry media and wet materials directly contact) and indirect heat transfer rotary drum dryer (the required heat for drying passed to the wet material by the cylinder wall indirectly). Because of low transfer efficiency and structural complexity, indirect heat rotary drum dryer is hardly to be chosen. Direct heat transfer rotary drum dryer is divided into downstream and upstream in accordance with the direction of flow of the drying medium and the material. The main part of direct heat transfer rotary drum dryer is a rotating cylinder with a slight angle to the horizon. Cylinder is transmitted by gear, with the general speed of 2 ~ 6r/min. The inclination of the cylinder is decided by its length, usually between 1 ° to 5 °. The material is feed from the higher part of the drum and contacts with hot air. With the rotation of the cylinder, the material flows to the lower end dried and discharged under the force of gravity. Because the dryer is working under negative pressure conditions, the feeding and discharging are sealed to prevent air leakage.
