Abstract:
A method and apparatus for paint insulation in electrostatic coating, wherein an insulating hollow member is grounded at its outer peripheral wall to prevent the rise in the potential at its inner wall. Consequently, drops of conductive paint such as water-base paint can be easily and continuously insulated when they fall from the upper part of the insulating hollow member.
Abstract:
A device for insulating the spray liquid source from the high tension voltage of an electrostatic spray system when using an electrically conductive spray liquid. The device comprises a spray gun (13), a supply line (12) which connects the spray gun (13) to a spray liquid reservoir (10) and which includes a vessel (16) containing a barrier forming liquid (17) of low electrical conductivity and a density other than that of the spray liquid. The vessel (16), which is substantially non-conductive is connected at its inlet end (24) to the earth potential and at its outlet end (19) to the same high potential as the spray gun (13). An electrode means (22; 25) is provided in the vessel (16) to expose the spray liquid passing through the vessel (16) to at least one intermediate potential for controlling the tension gradient in the barrier forming liquid by limiting and controlling the charging of the spray liquid.
Abstract:
A method and apparatus for paint insulation in electrostatic coating, wherein an insulating hollow member is grounded at its outer peripheral wall to prevent the rise in the potential at its inner wall. Consequently, drops of conductive paint such as water-base paint can be easily and continuously insulated when they fall from the upper part of the insulating hollow member.
Abstract:
A method and a device for insulating the spray liquid source from the high tension voltage of an electrostatic spray gun (13) when using an electrically conductive spray liquid. The spray liquid supply line (12) comprises an insulating device (14) in the form of a closed vessel (16; 26; 36) containing an electrically non-conductive liquid which is not mixable with the spray liquid and which has a density different from that of the latter. A sprinkler nozzle (21; 31; 41) is arranged to disintegrate the spray liquid into drops which are transported through the insulating liquid (17; 27; 35) by the influence of the difference in gravity acting on the two liquids. The spray liquid drops form a discontinuation of the electrical lead through which the high tension voltage propagates upstreams through the supply line (12). Thereby, the upstream parts of the supply line (12) including the spray liquid feed pump (11) and the spray liquid receptacle (10) are not reached by the high tension voltage. A pump (30; 40) and passages (27, 28; 37, 38) are arranged to forcibly circulate the insulating liquid (17; 27) within the vessel (16; 26; 36) such that a movement is superimposed upon the spray liquid transportation movement such that the spray liquid flow capacity through the insulating device is thereby increased.
Abstract:
A method and apparatus for paint insulation in electrostatic coating, wherein an insulating hollow member is grounded at its outer peripheral wall to prevent the rise in the potential at its inner wall. Consequently, drops of conductive paint such as water-base paint can be easily and continuously insulated when they fall from the upper part of the insulating hollow member.
Abstract:
A method and a device for insulating the spray liquid source from the high tension voltage of an electrostatic spray gun (13) when using an electrically conductive spray liquid. The spray liquid supply line (12) comprises an insulating device (14) in the form of a closed vessel (16; 26; 36) containing an electrically non-conductive liquid which is not mixable with the spray liquid and which has a density different from that of the latter. A sprinkler nozzle (21; 31; 41) is arranged to disintegrate the spray liquid into drops which are transported through the insulating liquid (17; 27; 35) by the influence of the difference in gravity acting on the two liquids. The spray liquid drops form a discontinuation of the electrical lead through which the high tension voltage propagates upstreams through the supply line (12). Thereby, the upstream parts of the supply line (12) including the spray liquid feed pump (11) and the spray liquid receptacle (10) are not reached by the high tension voltage. A pump (30; 40) and passages (27, 28; 37, 38) are arranged to forcibly circulate the insulating liquid (17; 27) within the vessel (16; 26; 36) such that a movement is superimposed upon the spray liquid transportation movement such that the spray liquid flow capacity through the insulating device is thereby increased.
Abstract:
An isolator (11) for electrically isolating an electrostatically charged, electrically conductive coating material supply line from a grounded source of conductive coating material (10) while continuously transferring coating material from the source (10) to the supply line. The isolator (11) includes a receptacle (21) for a charged coating material reservoir and an insulative housing (59) surrounding the charged coating material receptacle (21). The coating material in the receptacle (21) is fed through an outlet (22) to the supply line for an electrostatic coating device (12), which is electrostatically charged. Due to the conductive nature of the coating material, the electrostatic potential at the coating device (12) is coupled through the coating material, and the reservoir of coating material in the receptacle (21) is likewise electrostatically charged. The coating material from the grounded coating material source (10) is coupled to a grounded nozzle assembly (26) in a housing which is positioned above the charged coating material receptacle (21). The grounded coating material nozzle assembly (26) includes a nozzle (18) in a bottom portion (33) thereof, and the coating material in the grounded nozzle assembly (26) is mechanically vibrated to produce a pulsed jet droplet flow of electrostatic coating material from the nozzle (37) into the charged coating material receptacle (21).