喷头粒径谱和速度场的影响因素测试研究

Measurement experiments were carried out to measure the particle size spectrum and velocity field under different pressures for several small flow nozzles. Through the particle size spectrum measurement with different pressure and height from the nozzle, the particle size spectrum change was analyzed. The spaying particle size spectra with clean water and Emulsifiable Concentrate(EC) mixture were compared to analyze the impact of pesticide formulations on the particle size spectrum. The velocity field at the outlet of nozzle was measured and the velocity distribution of clean water and EC mixture was compared to analysis the pesticide formulations, nozzle type and pressure on the spraying characteristics of nozzles . The experiment results show that the pressure and formulation make different impact on the spraying characteristics for different nozzles. In general, the larger the spray pressure, the smaller the volume median diameter (VMD). Under the same pressure, the VMD of fan nozzle with EC spraying is bigger than that with water. For hollow cone with EC, the particle size spectrum changes, producing tiny droplets distribution . The droplet velocity of the fan nozzle increases with increasing pressure with both water and EC spraying, and the average droplet velocity of the hollow cone nozzle changes little with increasing pressure with water spraying due to reducing of the particle size. When spraying with EC, hollow cone nozzles produce smaller droplets and the droplet mean velocity decreases.)