Process and device for metering pulverulent materials

摘要

The invention is in a pneumatic powder ejector comprising a suction stage and an injection stage. The suction stage includes a suction chamber (16), a venturi (14) communicating a primary gas to the suction chamber and a lateral suction input (18) offset in relation to the downstream and of the venturi. The injection stage includes a nozzle (22), an injection chamber (36) and a diffuser (38). The stages are located within and coaxially of the body of a tubular ejector. The nozzle includes a path for powder and primary gas between the suction chamber and diffuser, and is formed to provide a flow path of reduced dimension to communicate a secondary or entrainment gas between the diffuser and injection station.