Effects of spray pressure, distance, angle and equivalent orifice diameter on spray uniformity for nano-pesticide application

In the application process of nano-pesticides, toxicity of the active ingredients on ecological diversity has attracted great attention. Improving the spray uniformity is the important method to ensure the nano-pesticide benign usage. The relative span (RS) is difficult to characterise the uniformity of the liquid volume and the droplet size at different points in the atomisation field. Therefore, we propose new evaluation indices for the spray uniformity and further discuss the influence of different spray parameters on spray uniformity. The results showed that the equivalent orifice diameter, spray pressure, and distance had little effect on the uniformity of the liquid volume on the spray cross-section. The increase in the equivalent orifice diameter could improve the uniformity of the droplet size span. The increase in the spray pressure also reduced the uniformity of the droplet size span. In addition, this study has provided positive guidance for nozzle design and nano-pesticide application.