| 摘要 |
1,037,521. Spray-producers. DE MACHINES ELECTROSTATIQUES S.A. Nov. 30,1962 [Dec. 8, 1961], No. 44056/61. Heading B2F. Electrostatic spraying apparatus comprises a nozzle having an outlet at one end through which particles suspended in a gas stream are discharged, said outlet being connected to a source of electric potential and means being provided for directing or deflecting the gas stream into a helical path so that the particles migrate towards the wall of the nozzle in their movement towards the outlet. The nozzle comprises a circular vortex chamber 8 opening into a divergent conical portion 9 which terminates in a sharp lip 9a. An annular chamber 10 at the inlet end of the nozzle is connected to the vortex chamber by inlet ports 11 at a tangent to the wall of the vortex chamber 8, Fig. 2 (not shown). The nozzle is secured to a spray gun by a locking ring 19. A low velocity primary air stream carrying particles of nylon or polyvinyl chloride passes along the gun barrel 4 and into the chamber 8. Here it is deflected into a helical path by a high velocity secondary air stream entering the chamber 8 via a passage 12, the annular chamber 10 and inlet ports 11. A trigger 18 actuates a switch 21 in the high voltage supply line to the nozzle and a valve 22 controlling the flow of secondary air to the nozzle. The nozzle may have a conical baffle in the portion 9. Alternatively, the vortex chamber and portion 9 may have a uniform cylindrical cross-section. In another embodiment, the chamber 8 has an involute cross-section having a single port entering it along a generally spiral path. The barrel 4 may have a non-circular cross-section, e.g. in the shape of a cross, formed with a helical twist to impart the desired motion to the primary air stream as it enters the nozzle. The secondary air stream may be omitted and helical motion imparted to the primary air stream by fixed helical blades in the nozzle inlet. |
