ANORDNING VID ETT SPRUTSYSTEM FOR ATT SELEKTIVT INFORA PULVER I EN GASSTROM

摘要

A powder feed control system employs an arrangement of conduits and valves for selectively directing a gas flow either through a powder feeder or through a bypass so as to quickly and precisely control the introduction of powder into and the removal of powder from the gas flow in a plasma spraying system. The arrangement of conduits and valves includes a two-way solenoid operated valve for directing the gas flow either into a powder feeder through a main conduit or into a bypass conduit which rejoins the main conduit on the other side of the powder feeder at a powder shutoff valve and a bypass and check valve. The bypass and check valve insures that the gas flow in the bypass conduit flows to the output rather than upstream to the powder shutoff valve. The powder shutoff valve includes a resilient member mounted within the bore of a housing and collapsible upon itself to close off an internal bore therein in response to the introduction of pressurized gas into a space between the housing bore and the resilient member. Air introduced into a cannister in the powder feeder with the loading of powder into the cannister is removed by an arrangement which includes a valve for selectively coupling the inside of the cannister to a vacuum source.