GB1301304A - - Google Patents

Abstract

1301304 Electrogasdynamic generators ELECTROGASDYNAMICS Inc 30 Dec 1969 [31 Dec 1968 19 Dec 1969] 63324/69 Heading H2A [Also in Division B2] In an E.G.D. generator, particularly for use with an electrostatic spray gun, turbulence is produced in the moving gas stream by surface discontinuities adjacent a corona discharge zone formed by ionizing and attractor electrodes 124, 194. As shown in Fig. 4, the electrodes are located between a conical insulating transition section 192 and an insulating sleeve 212 having a slightly diverging bore 158, and the discontinuities are formed by recesses 220, 216 on either side of electrode 194. A stream of seeded air enters the generator under pressure at an annular region 114 formed around an insulating sleeve 190 which positions the electrode 124 coaxially with respect to electrode 194, and, after accelerating through the section 192 to about sonic velocity, is converted into a charged aerosol by the electrode which sweeps through the bore 158 and impinges on a chargecollecting electrode 198. Only one recess, 220, may be provided or alternatively, Fig. 5 (not shown), the discontinuities may be formed by a stepped bore in the section 192. A paint spray gun incorporating the generator is shown in Fig. 3. The supply of seeded air is controlled by a trigger 96. After impinging on the electrode 198, the air stream expands into a bore 156 formed in a barrel 34 surrounding the generator and flows through an exit conduit 160 to the atomizing and charging assembly 36 to which paint is also supplied through a hose 24. Electrode 198 is connected to a charging electrode located adjacent the nozzle through which the atomized paint particles leave the gun. A chamber for seeding the air e.g. with paint solvent, is described, Fig. 2 (not shown).