Design and Development of a Greenhouse Electrostatic Sprayer and Evaluation of the Droplets Charging

Electrostatic spraying is the method that is noted for improving the spraying efficiency and droplet deposition on plant. The merit of this method is related to the generation of dynamic attraction between the charged pesticide droplets and plant which obtains plant peripheral coating ability against usual spraying methods. In this research design and evaluation of an electrostatic sprayer was described. In this sprayer, electric charging of droplets is performed through the induction method. Atomization of nozzle flow is accomplished by ultrasonic method and the generated droplets buoyancy and guiding them is achieved by airflow of a fan. To evaluate voltage effect, air speed and liquid flow rate on quantity of droplet charging, the tests were conducted in a closed environment. The results showed the positive effect of inductive voltage on charged droplets creation. Increasing of fan speed improves the droplet charging by increasing of passed air flow rate. However, because of wetting phenomenon, increasing of spray flow rate has a negative role during charging process. The maximum charging is occurred at 25 ml/min flow rate, voltage of 7 kV and air flow speed of 23 m/s and the resulting current is about 0.42 μA.