Low-cost Electrostatic Spray Charging System as an Attachment to Powered Knapsack Mist-blower

Abstract

The introduction of electrically charged sprays in the agricultural application has become inevitable for better control on droplet transference with reduced drift and an increase in application efficiency with less spray chemical requirements. The present study was undertaken to develop an electrostatic induction spray charging system as an attachment to powered knapsack mist-blower. A high voltage generator was fabricated on the basis of the Cockcroft-Walton voltage multiplier principle with the input of 6 V DC battery to provide the high voltage required at the developed charging electrode assembly (Model III, Model IV and Model V) for inducing an electrostatic charge on spray droplets. The three prototypes (III, IV, and V) were evaluated for charge to mass ratio (mC.kg-1) at five electrode potentials (1 kV, 2 kV, 3 kV, 4 kV, and 5 kV), four electrode placement positions (0 mm, 5 mm, 10 mm and 15 mm) and five distances (50 cm, 100 cm, 150 cm, 200 cm, and 250 cm) from the nozzle. Model V with electrode voltage potential at 5 kV and EPP at 5 mm shown the maximum CMR value (1.088 mC.kg-1), followed by Model III (0.888 mC.kg-1) and Model IV (0.777 mC.kg-1) with similar combination of variables. In contrast with a commercial system (ESS-MBP90) it was observed that except at 50 cm distance from the nozzle, Model V (at 4 kV and 5 kV) surpassed the commercial system in CMR from 100 cm to 250 cm distance. The droplet spectrum of the developed system was analyzed and observed that the size of droplets was 100 to 200 µm. The deposition efficiency of the developed system was on par with that commercial unit and was within the range of 60 to 70 percent. The developed system found to be cost-effective and significantly consistent on par with the commercial system.