Apparatus for spraying a powder coating with enclosure surrounding a

Abstract

A powder product to be sprayed is conveyed by a stream of gas in a flexible conduit between a storage tank and a spray orifice from which a mixture of the gas and the product is ejected. The mixture is agitated upstream of and in the vicinity of this orifice by oscillating a section of the flexible conduit in the vicinity of this orifice. The powder product sprayer comprises a flexible conduit and a device for circulating a mixture of the product and the gas in this conduit. It further comprises an enclosure surrounding a section of the conduit and a device for oscillating this section of the conduit. The device for oscillating the conduit may comprise a vibrator fixed to this section of the conduit and free to move inside the enclosure. The vibrator may comprise an annular cage surrounding and fixed to this section of the conduit, a ball movable inside the cage and a device for injecting air into the cage in a direction adapted to cause movement of the ball inside the cage. Alternatively, the device for oscillating the conduit may comprise an annular body attached to an inside wall of the enclosure with an annular cavity in this annular body. A device injects air into the cavity and holes in an inside lateral wall of the body discharge in a direction inclined towards the relevant section of the conduit, which passes axially through the annular body. The inside diameter of the annular body is greater than the diameter of the section of the conduit concerned.