Because of its simple design, versatility, flexibility, large capacity and handle multiple types of raw materials (crushed minerals from the multi-cutting plant) capacity. Drying gas and for rolling the bed transfer process contribution to the team of only 5% of the wet solid materials, the convection heat and mass transfer between the main areas being made on the Raising of the particles in a "floating down" period. In addition, the material is relatively small capacity, 10% - 20%. Therefore, the traditional axial flow rotary drying machine and the gas volume is usually large, medium and relatively high prices, energy. Specially designed rotary drying machine, such as hole-shaped rotary drying machine and heat - dry air flows through the rolling bed of particles, with good drying properties, but this type of drying machine is the high capital investment and maintenance costs.