Drum dryer is hot air from the rear forward movement, full contact with the material, by heat conduction, convection, radiation, heat transfer fully utilized; the heat directly to the material, the material constant moisture is evaporated in the cylinder body, the spout of the wind means a lot of water, wet gas extraction, to prevent secondary pollution caused by dust efflux; stir through the inner helix, sweep scattered, copy board, promoting the movement of materials to complete the drying process; countercurrent conduction dehumidifying, avoid reduce duplication drying process. Dryer drum main features: 1, dry strength, due to the highly dispersed material in the gas stream, the entire surface of the particles of active dry effective area. 2, drying time is short processing capacity, high thermal efficiency. When dry unbound water, thermal efficiency up to 60%. 3, the air dryer simple structure, small footprint, easy to build and repair. 4, dryer to achieve a "zero level thrust", greatly reducing wear riding wheel block, cylinder smooth and reliable operation. 5, the dryer uses "Spherical Roller-type device", so with the idler and roller ring forever linear contact, thereby greatly reducing the wear and power loss.