| 摘要 |
1404984 Spray producers; generating foam NORDSON CORP 27 July 1972 [30 July 1971] 35254/72 Heading B1C and B2F Liquid discharged from a spray gun is atomised in the atmosphere by the expansion and bursting of microbubbles of gas which have been formed previously within the gun by injecting gas into a thin film of liquid to form a froth. The liquid is caused to flow under pressure, through an annulus 68, Fig 2, as a thin film to which is supplied through radial channels 41, air at a slightly greater pressure. The results in the formation of a froth containing bubbles which are carried by the liquid to a chamber 75. Upon leaving the gun through an orifice 78 the bubbles expand and burst to atomise the liquid. Actuation of a trigger 18, Fig 1, opens an air valve 23 to admit air through conduit 16, the air passing through elements 21, 30, 31, 32, 33 and a needle valve 35, ports 38 and chamber 40 to the channels 41. A needle 45 is also retracted to admit the liquid supplied through a conduit 17. In a modification, Figs 8, 9, 10 (not shown), the liquid is supplied through vertical bores (111) transversely of a flat narrow channel (106) formed between abuting plates (101), (102) while the air is supplied transversely of the channel via a slot (112), the froth being ejected through an elongated outlet (113). A second air slot may be provided. The gun may have electrostatic charging means. |
