Claims
- 1. In an electrostatic powder spray system having an electrostatic spray device which electrostatically charges the powder being sprayed therefrom and having a powder feeder for supplying an air-powder mixture to said spray device, said feeder having an output line connected to said spray device through which said mixture is so supplied, the improvement for removing from the particles of powder electrostatic charge which is opposite from that imposed by said spray device comprising:
- an electrical conductor means 75 positioned upstream of said electrostatic spray device adjacent said powder feeder to contact powder passing through said line and electrically biased with respect to said electrostatic spray device so as to discharge said powder with respect to said device before said powder is electrostatically charged at said device.
- 2. The improvement of claim 1 wherein:
- said conductor means is grounded with respect to the ground potential of said spray device.
- 3. The improvement of claim 1 wherein:
- said conductor means is in the form of an electrically conductive tube forming said line.
- 4. The improvement of claim 1 wherein:
- said conductor means is in the form of a wire extending a distance along the length of said line within said line.
- 5. A method for increasing the efficiency of an electrostatic powder spray system of the type having an electrostatic spray device for electrostatically charging solid particulate powder as the powder is sprayed therefrom,
- which method comprises the steps of
- removing from the particles of powder electrostatic charge opposite to that which is imposed by saidspray device upstream of the electrostatic spray device by passing said powder over an electrical conductor which is electrically biased oppositely from the electrostatic spray device, and
- applying an electrostatic charge to the powder as the powder is discharged from the device at a location remote from the powder discharge electrical conductors.
Parent Case Info
This is a division of application Ser. No. 259,591, filed June 6, 1972, now U.S. Pat. No. 3,870,375 and a continuation-in-part of U.S. application Ser. No. 194,830 filed Nov. 2, 1971 now U.S. Pat. No. 3,746,254.
US Referenced Citations (7)
Divisions (1)
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Number |
Date |
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Parent |
259591 |
Jun 1972 |
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Continuation in Parts (1)
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Number |
Date |
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194830 |
Nov 1971 |
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