| 摘要 |
A powder spray system for applying particulate powder material to a substrate (12) includes a volumetric or gravimetric dry material feeding device (16) having an outlet (22) connected to a manifold (26) formed with an internal cavity (28) and a plurality of passageways communicating with the internal cavity. A highly accurately metered quantity of powder is transmitted into the internal cavity (28) of the manifold (26), which is either applied to the substrate (12) or recirculated back to the powder source. An air amplifier (52) connected to one of the passageways is operable to draw ambient air through a vent passageway (36) into the internal cavity (28) of the manifold (26) to form a stream of air-entrained powder. The powder stream is then drawn out of the internal cavity (28) of the manifold (26) by the air amplifier (52) into a spray gun (38) for discharge onto the substrate (12). A second air amplifier (64) connected to another passageway (34) formed in the manifold (26) is operated when the first air amplifier (52) in the spray gun (38) is closed to draw the powder entering the manifold (26) into a return line (76) for recirculation back to the powder source (16). |
