A system and method of pumping a constant volume of powder

摘要

An apparatus and method for pumping a constant volume of powder to a powder spray gun (12) includes a powder pump which meters the powder into a stream of air so that a constant volume of the air entrained powder is distributed to the spray gun (12). The invention also discloses a pressure equalizing system (104) that prevents powder leakage across a powder metering system that meters powder from a reservoir (16) into an outlet tube carrying the constant velocity stream of air. A control system is disclosed which adjusts the rate at which powder is metered into the outlet tube (20) so that the mass flow of powder exiting the outlet tube (20) remains constant.