摘要 |
PCT No. PCT/GB94/02407 Sec. 371 Date May 14, 1996 Sec. 102(e) Date May 14, 1996 PCT Filed Nov. 2, 1994 PCT Pub. No. WO95/13879 PCT Pub. Date May 26, 1995An electrostatic spraying device for use in spraying liquids having resistivities of the order of 5x106 ohmxcm and viscosities of the order of 1 Poise at a spraying rate up to at least 4 cc/min (especially paint formulations) is provided with an annular shroud (112) of semi-insulating material (e.g. bulk resistivity of the order of 1011 to 1012 ohmxcm) which is electrically connected to a high voltage generator (126) for supplying high voltage to liquid emerging at the outlet of the nozzle (114). In this way, a voltage is established on the annular electrode (126) which is of the same polarity, and substantially the same magnitude, as the voltage applied to the liquid thereby modifying the potential gradient in the immediate vicinity of the nozzle outlet so as to allow the use of the high voltage needed to effect efficient spraying of liquids having the specified resistivity and viscosity at flow rates up to at least 4 cc/min.
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