荷电喷雾技术是一种利用静电作用控制液滴运动来改善喷雾特性的手段,它的效果受到喷雾荷电性能的直接影响。为此,从水雾感应荷电理论出发,建立雾滴群荷电量的理论公式,通过试验研究电极参数对雾滴荷电性能的影响,并测试了喷雾特性。结果表明:1)最佳极间距与液膜破碎长度有关,完全破碎前荷质比随极间距增加而增加,完全破碎后荷质比随极间距增加而减小,荷电性能随电极环直径减小而增大;2)荷电喷雾能提高药液在目标物表面和背部的沉积量,同时改善均匀性;3)雾滴粒径在静电力作用下逐步减小,分布趋于均匀。
Charged-spray technology helps to improve spray through controlling droplets motion with electrostatic effects, its effect is directly determined by the charging of spray droplets. We established theoretical equations of droplet group charge based on the water induction charged theory, study the effects of electrode figuration on droplet charging through experiments, and tested according spray characteristics. The results show are as follws. 1) There is an optimized electrode position related to breakup length. With increasing distance between nozzle and electrode, CMR( charge to mass ratio) increases before liquid film completely breaks, then it decreases after the film break. Meanwhile, the spray charging is enhanced with decreasing annular electrode diameter. 2) Charging spray improves the spray deposition on both sides of the target, while improving the uniformity of deposition. 3) Sauter mean diameters of spray droplets gradually decrease under the effect of electrostatic force, and tend to be distributing more evenly.