Operation of the Williams Impact Dryer Mill system is completely automated. Feeder (A) introduces raw material into the grinding chamber (B) along with heated gas at a rate that is determined by pressure and temperature sensors located in the system and adjusted automatically. In the grinding chamber, controlled action by the rotating hammers reduces feed to the desired product size. Simultaneously, the hot gas removes moisture. Drying is greatly accelerated by the increased surface area as the particle size is reduced. Controlled velocity in the grinding chamber enables the flow of hot gas to selectively air convey particles, ground to the proper size, up and out of the grinding chamber. Airflow is maintained by the main mill fan (C). The ground product, suspended in air, passes through the adjustable Williams Spinner Separator or Velocity Separator (D) where an accurate size classification is made.

Product-sized material is removed from the air-stream by the cyclone collector (E). Airborne fines which remain entrained in the exhaust gas from the cyclone collector are moved by a high-efficiency fabric dust collector (F). Extreme fines are transported by a second conveyor (G). An exhaust fan discharges clean gases and evaporated moisture from the system.

Patented Inert Gas System: To process explosive material such as coal, and to process all materials with greater thermal efficiency, portions of the exhaust gas generated by exhaust fan (J) can be recycled to burner (H) where the oxygen is consumed in the combustion process.