An electrostatic charging system for hydraulic spray nozzles

Abstract This paper describes a system for applying an electrostatic charge to water drops produced by a hydraulic nozzle. The charge is applied by induction where the spray liquid is at a potential of up to 10 kV and the induction electrode is earthed. Three problems commonly encountered in charging systems have been overcome, viz. electrical discharge of the spray caused by liquid on the induction electrode, short circuiting of the power supply caused by setting of the equipment and raising the sprayer tank to a high voltage caused by using a conducting spray liquid. Even though no attempt was made to optimize the charge level of the system, it was shown that significantly improved deposition and uniformity of spray liquid was possible on artificial targets with the nozzle moving at 2 m/s.