Abstract:
Abstract: Pesticides electrostatic spray technology of can improve the deposition efficiency of pesticides on the hidded faces of leaves and reduce the pollution of pesticides to the environment. It has become a hot topic for scholars at home and abroad. In order to clarify the research and industrial status of pesticide electrostatic spray technology and the bottlenecks in the industry, the basic theory, mechanism research and analysis, indoor/outdoor electrostatic spray effect evaluation and electrostatic spray equipment industry status of pesticide electrostatic spray technology was systematically analyzed in this paper. Firstly, the droplets charging modes, the charged droplets dynamics, the charge-to-mass ratio(CMR) and the retention time were mainly overviewed. The conclusions about the main force of the charged droplets, the optimal charging parameter of the inductive charging and the reasonable comparison method for the charge-to-mass ratio were gained that the main force imposed charging droplet were electrostatic force, airflow drag force and gravity; Inductive charging is the most commonly used charging technology for electrostatic spray of pesticides, and the best charging voltage was 6-10kV, the electrode material is nickel or nickel-plated copper material, and the distance between the electrode and the nozzle outlet was 5 mm or less. When comparing the CMR between different sprayers, all the current, spray volume, measuring distance, droplet spectrum and particle size, air velocity and distribution should be expressed. Secondly, the test methods of charge-to-mass ratio, potential, droplet size and droplet velocity in electrostatic spray were introduced. The Faraday barrel, Faraday cage and mesh target method were the 3 main methods to measure the CMR. The application of phase doppler particle analyzer (PDPA) and CFD simulation in electrostatic spray technology were proposed. But the application of these advanced testing technologies and the application details of CFD simulation in electrostatic spray still need further study. Thirdly, the influence mechanism of charged droplet deposition was reviewed from 4 aspects of charging parameters, environmental parameters, working parameters and target parameters. It was believed that the electrostatic spray deposition efficiency was affected by the charging parameters, environmental parameters, target parameters and working parameters, but the mechanism of influence was still unclear and still needs further attention. At last, a large number of electrostatic spray indoor/outdoor effect evaluation tests showed that the charged droplets were driven by electrostatic force, airflow drag force and gravity, which contribute to the deposition of mist droplets in the leaves, but the electrostatic spray on the droplets drifting and penetrating properties was still no conclusion. Last for the most, the electrostatic spray technology had the advantage of high efficiency of droplet deposition, but it was still not widely used due to its unsatisfactory application effect. Because of the high sensitivity of various parameters to droplet deposition, the complexity of application environment and objects were the biggest challenges in the application of electrostatic spray technology, and the main bottlenecks were the short retention time and easily adsorbed by the sprayer and the human body. 3 suggestion were listed as: (1) Continue to carry out the research on the matching parameters of the charging parameters, air velocity and the charged droplets, increasing the maximum initial charge, meanwhile ensuring the effective charge when reaching the target.(2) Strengthening the research on mechanism of charged droplet deposition to clarify the key parameters affecting the deposition of charged droplets.(3) In order to ensure the actual effect of electrostatic spray, it is recommended to develop any electrostatic spray equipment in accordance with the specific equipment to develop detailed electrostatic spray operation specifications.