Weigher feed system for powders - has separate automatic coarse and fine metering systems and screw conveyer

摘要

A weigher feed system is for pneumatically conveyed powdered or grannular materials. It has premetering of a coarse flow followed by fine metering to the set weight. Before coarse premetering, a quantity of material larger than normally needed for fine metering is separated from the flow and is held back for mechanical fine metering. Coarse premetering is then effected and when a coarse flow contact is reached in the weighter container the retained quantity of material is used for fine metering until the set weight is reached. Pref. the quantity for fine metering is separated by a cyclone separator (1) and deposited onto e.g. a screw conveyor (3).