Pulse-operated point feeder

摘要

A point feeder for metering powder materials, for example aluminum oxide, to a Hall-Heroult electrolysis cell includes a vertical tube and a horizontal tube which are joined so that they form substantially an L-shaped channel with a material input at an upper end of the vertical tube and a material output at an end of the horizontal tube. The vertical tube is provided with a nozzle device which has one or more downward-facing holes which allow air to penetrate in the form of pulsed air flows to the lower part of the vertical tube and to the whole of the horizontal tube.