Patent ID: 6254684
Filing Date: 2001-07-03
Classification: B05B

Abstract:
A powder-spraying appliance for electrostatic powder coating, comprising:a chamber having a cross-section, a length between 7 and 15 cm, a diameter between 2 to 4 cm, an interior, and a main axis;an outlet disposed downstream of said chamber;a plurality of high-voltage electrodes disposed in said chamber for internal charging of a powder of a powder/air mixture, said plurality of high-voltage electrodes annularly distributed in a region upstream of said outlet;a tubular earth electrode disposed centered in said main axis of said chamber and a spatial distance between said tubular earth electrode and said plurality of high-voltage electrodes being between 7 and 14 cm, said tubular earth electrode having an end directed towards said interior of said chamber and said end having a head part formed with rounded edges closing off said end;a covering made of an insulating material covering said head part;a supply conduit for conducting the powder/air mixture and having a cross-section being smaller than said cross-section of said chamber, said supply conduit opening into said chamber transversely to a spraying direction resulting in an intensive swirling of the powder/air mixture; andsaid tubular earth electrode and said plurality of high-voltage electrodes receiving cleaning air for avoiding powder deposits on said tubular earth electrode and said plurality of high-voltage electrodes.