Study on the Physical Properties of Spray Liquid Droplets Generated as a Result of Air-assisted Electrostatic Spraying System

——Effects of Air-assisted Electrostatic Spraying on Charge to Mass Ratio and Spray Distance——

Abstract

We studied the physical properties of spray liquid droplets generated as a result of air-assisted electrostatic spraying with an aim to improve the pesticide adherence performance demonstrated in a crop community by providing air-assistance from behind the spray nozzle for the control of pests in a greenhouse, plant factory, etc. In the course of this study, we used an electrostatic spraying system equipped with an annular electrode in a wind tunnel in order to examine the relationship between the air-assisted wind speed, the diameter of spray liquid droplets, the spray nozzle height, spray distance, the electrode voltage, the distribution of precipitation of spray liquid droplets, the specific charge of liquid droplets, etc. As a consequence, we identified the increase in the volume of spray liquid droplets reaching the object by horizontally spraying the liquid in an air-assisted manner through the use of a hollow conical spray nozzle and found out that the specific charge of liquid droplets measured at the 100cm spray distance was approx. 8 times greater than when no air-assisted electrostatic spraying was conducted.