Research On Air-assisted Electrostatic Induction Spraying System

Owing to the quality degradation of cotton caused by non-uniform spray of defoliant to machine harvest cotton growing in Xingjiang Autonomous Region, a pneumatic electrostatic sprayer whose design was based on pneumatic type electrostatic spray technology was developed. The sprayer was designed with an aim of achieving an optimum droplets deposition and distribution on the surface of the crops, attain a high deposition rate at the back of the crops and concealment part as well as reduce tiny droplet drift and invalid ground deposition. To evaluate the performance of the sprayer, both experimental tests and modeling approach using CFD software were employed. The experimental lab tests on the sprayer’s deposition rate encompass tests for both with and without electrostatic spraying system settings. The results were further verified with similar tests on Xinjiang wine grapes and cotton field.This article gives an insight analysis of the mechanism of the droplets charging process, transport process and subsidence progress, CFD simulation of the movement and deposition of the droplets of an air-assisted electrostatic spraying and an optimized structure and working parameter of the sprayer’s critical component.The results obtained showed that; both droplets deposition uniformity and deposition rate improves if the gas pressure and wind velocity increase to a certain range. In addition, the current value increase gradually along with increase in voltage within-100 V～-1200 V, attain a peak at a voltage of-1200 V then decline with further increase in charging voltage. Moreover, tiny droplets increase along with increase in pressure; 0.15 MPa～0.20 MPa achieving a more uniform droplets distribution. Conclusively, droplets atomization performance and electrical load orthogonal test results indicated that, charge-mass ratio and droplets deposition distribution peak at gas pressure of 0.2 MPa, liquid pressure of 0.0125 MPa and a charging voltage of-1200 V.The effect of electrostatic spray is better and droplets deposition is more uniform because of the good adsorption of the charged droplets, electrostatic spray hence increase the deposition rate of concealment part. Hence, the potential of using air-assisted and electrostatic spraying system to achieve reduced drift and improved droplets deposition was attained.