This is a very simple Screw (Spiral) Feeder and hopper to supply zinc dust to a Merrill Crowe Precipitation system. Its variable speed screw can rotate between 4.17 and 41.7 RPM. The spiral on this zinc dust distributor is 30 mm in diameter by 390 mm long. It is powered by a 3/4 HP electric motor. The zinc delivery or dosage capacity ranges around 5 to 10 kg/h.