Nowadays, with the rapid development of China's economy, science and technology are also constantly developing and progressing, and mechanical equipment is also constantly updating. The drum dryer is also known as the rotary drum dryer or the drum dryer, which is a common and widely used drying equipment in mining equipment. It is suitable for drying magnetic, heavy and floating concentrates of metal and non-metal ores, clay of cement industry and slime of coal mine industry.

According to the heat transfer mode between the drying medium and the wet material, there are two types of direct heat transfer drum dryers and indirect heat transfer drum dryers. Indirect heat transfer rotary dryer is rarely used due to low transmission efficiency and complex structure, so it will not be introduced here. Direct heat transfer rotary dryer is divided into two types according to the direction of drying medium and material flow: forward flow and reverse flow.

The main body of the direct heat transfer rotary dryer is a rotary cylinder slightly inclined to the horizontal line. The cylinder is driven by gears, and the rotation speed is generally 2-6r / min. the inclination of the cylinder is related to its length, usually between 1 ° - 5 °. The materials are fed from the higher section of the rotary drum and contacted with the hot air. With the rotation of the drum, the materials flow to the lower end under the action of gravity and are dried and discharged. Since the dryer works under negative pressure, the feeding and discharging ends are sealed to avoid air leakage.

When the drum dryer works, the fresh air of the equipment is heated to the set temperature when passing through the heat exchanger. Through the scientific and reasonable hot air circulation and hot air distribution mode, the hot air flows through the materials of the dryer for uniform heat and mass exchange. The hot air in each unit circulates under the action of the circulating spiral classifier, and constantly compensates the attenuated temperature to the set state, The system continuously replenishes the fresh air of the dryer, discharges the high humidity air, and discharges the low-temperature and high humidity air to smoothly and efficiently complete the whole dryer process. For materials whose material temperature is not allowed to exceed 60 ℃, the gas temperature of the dryer in the primary drying section can be below 120. The retention time of materials in the final drying section is 3-6 of that in the initial drying section. The paving thickness is 2-4 of the initial dry. For the requirement that the material temperature does not exceed 60, a dryer gas of about 80 ℃ can be used. Use multi-stage combination to give play to the performance advantages of the belt dryer, so as to make the drying more uniform.