Electrostatic spray gun

Apparatus for electrostatically charging sprayed liquid particles through inductive charging of the particles and/or ion formation by corona discharge, comprising:

• a spray gun having a liquid spray nozzle for atomizing a liquid and directing atomized liquid particles along a spray axis;
• a needle in the path of said particles;
• an electrode assembly including electrode means;
• means for connecting a high voltage power supply of a first polarity to said electrode means;
• means mounting said electrode assembly on said spray gun to position said electrode means around said spray axis to produce an electrostatic charging zone coaxial with said spray axis through which said atomized particles pass, said electrode means being located forwardly of said liquid spray nozzle and sufficiently close to said spray axis to cause a voltage applied to said electrode means to produce in said charging zone a radial electrostatic field gradient sufficient to induce charges on electrically conductive liquid particles and to produce a corona discharge to said needle to cause ions to accumulate on electrically nonconductive liquid particles so as to charge said particles to the opposite electrical polarity as the voltage applied to said electrode means, said electrode means being spaced sufficiently far from said nozzle to suppress flashover.