Research On Flow Characteristic And Deposition Performance Based On Contacted Charge

Electrostatic spray as a high effective spray technique has outstanding advantages. Nowadays, it was obtain a lot of attention in our country, but multi-nozzle charging problems can only be solved to greatly improve the operating efficiency. According to the existing situations, a lot of literatures were readied. In this paper, flow characteristic and deposition performance were studied for electrostatic boom spraying, which aimed to get its flow patterns and provide a theoretical basis for electrostatic sprayer spray design.The main research and work results include in the following aspects:(1) Electrostatic boom spray system designElectrostatic boom spray test system was designed and developed in this paper. Electrostatic boom spray system consists of two parts: high-voltage charging system and boom sprayer operation and control system. Contact charging method was used in the design of high voltage power supply system. By analyzing the charging principle and taking account of electrostatic spraying system requirements, the charging electrode and high voltage generator model design and selection were mainly completed in this part.(2) Experimental study on electrostatic charging characteristics of boom sprayIn the laboratory environment, charge to mass ratio measuring method which was based on Faraday cage was used to measure the charge to mass ratio of electrostatic boom spraying. The charge to mass ratio of different nozzles was tested under different pressure and charging voltage, which provide selection parameters for the follow tests. The nozzle conformance testing of flow rate and charge to mass ratio was carried out to ensure the nozzles consistency.(3) Flow field measurement of electrostatic boom sprayDroplet size distribution and velocity field of electrostatic boom spray system was measured by using particle image velocimetry and laser particle size analyzer. The influence of different pressure, different charging voltage for the flow field under measurement plane at different heights of boom spray was studied, while the atomization angle was measured by PIV image. The spray flow patterns and influence of different conditions on the droplet size and velocity field were explored to provide a test parameters set reference for subsequent deposition.(4) Spray deposition test of electrostatic boom sprayingSpray deposition for booting stage of rice plants of electrostatic boom spray system were tested. Deposition characteristics of the upper blade, middle blade and lower blade rice plants were gained for different row spacing, spray pressure and charging voltage. The significant effect of deposition factors was analyzed by applies the analysis of variance with different row spacing under different operating conditions.