Three drum dryer works when the work material by feeding device into the inner rotary drum and achieve downstream drying, the material in the inner constantly took a copy board, scattered spiral marching heat exchange, material movement the other end to the inner layer into the middle, countercurrent drying, the material is repeated constantly in the middle Yang Jin, was traveling way to step back two steps forward, both fully absorb the material in the middle inner cylinder the heat, and absorbing the middle heat roller, and prolong the drying time, the best material in this dry state. The other end of the line to the middle of material falling into the outer layer of the material in the outer drum rectangular multi-loop approach to travel, to the drying effect of the material in the hot air discharge action fast marching drum, there is no effect of the wet material to dry weight and not due to rapid the road, the material within this rectangle copy board is fully dried, thereby completing the drying purposes. Installation test: 1, the device should be installed on a level concrete foundation with anchor bolts. 2, the installation should pay attention to the main body vertical and horizontal. 3. After installation check all parts for loose bolts and host doors are secure and, if requested to tighten. 4, according to the configuration of power equipment and power line control switch. 5, the inspection is completed, empty load test, test the normal production. Three drum dryer, also known as the three return dryer are wet material drying equipment series, is in monocular rotary dryer based on the improvement of energy-efficient products. Such dryer improve the internal structure of the original single cylinder rotary dryer, increasing the pre-drying of wet material into the machine before the wet material and prolong the drying time in the machine, plus sealing, moisture and sound supporting measures, so that the drying machinery production capacity compared with the original single cylinder dryer, increase 50-80%, unit volume evaporation strength up to 120-180kg / m3, standard coal consumption of only 6-8kg / t. Three drum dryer is widely used in various industries slag, clay, coal, iron, ore, and other mixed materials, construction of dry mortar, yellow sand, etc. as well as chemical, foundry industry raw materials drying.