The article covers the principle of operation, as well as the results of theoretical research of the improved technology of the screw mixer-feeder unit of a new construction for the drying drum that allows the initial mixing of cotton raw materials with hot air and improves the ecological stability of the environment. The forces acting on the cotton pieces during the drying process have been determined. The graphs of the dependence of the amount of moisture release on the speed and density of hot air at different temperatures during the drying of cotton raw materials have been obtained. The laws of movement of cotton pieces in the screw conveyor along the surface of the screw have been theoretically substantiated.