The clean heat medium heated by the heat source enters the drying chamber along the tangent form, and forms a powerful vortex rotating airflow together with the mechanical stirring mechanism. Wet materials into the drying chamber by the feeder in quantitative mixing and vortex airflow by crushing and drying. The drying chamber is arranged on the top of a size classifier, meet the requirements of dry powder discharged from the top of the tower, collected from the back of the separator, does not meet the requirements of the larger particle drying by the classification ring block, back to the drying chamber, continue to be crushed dry, until dry into a qualified product, with the hot air from the drying chamber, collected by separator. The clean tail gas is evacuated under the action of the draft fan.