A capacitive type of electrostatic spraying nozzle

Many toxic pesticides are dispensed to protect food crops from pests in farm fields. Greater than 90% of pesticides are commonly applied as aqueous-based sprays. When dispensed with conventional nozzles, a large portion of the spray is often lost as airborne drifts of droplets. In addition, there is a lack of deposition onto the plants due to the rapid gravitational settling of droplets beneath the soil surface. Thus, target deposition efficiencies poorer than 25% are often encountered in agricultural pesticides. Electrostatic spraying technology offers a very favorable means of increasing pesticide droplet deposition onto biological surfaces of living crops. More than a doubling in efficiency is a reasonable goal. In this paper, a new capacitive type of electrostatic spraying nozzle, which utilizes a ring induction electrode installed on the outside of a nozzle frame cone and a pulsed voltage, is proposed and studied experimentally. The results of this study indicate that the proposed capacitive type of electrostatic spraying nozzle exhibits a large current deposition of aqueous sprays on the sample target. Thus, it has promise to be applied as an effective electrostatic spraying nozzle. (C) 2002 Elsevier Science B.V. All rights reserved.