Droplet Size Distribution of Air-Carrier Sprayer for Orchard

Droplet size distributions of the ceramic hollow cone nozzles used in the air-carrier sprayer for orchard were investigated at several locations under various nozzle injection pressures, air velocities and sprayer velocities. Droplet size was measured by the Malvern particle size analyzer for the horizontal spray and by the water sensitive paper and an image processing system for the vertical spray. For the horizontal and vertical sprays, the volume mean diameter was decreased with the distance from the nozzle due to evaporation. The air velocity of 15-20 m/s was recommended for both minimum drift and pests control. The volume mean diameter of the sprayer was in the range of 40-180 μm for the horizontal spray. The sprayer speed of 11.9 km/h was suitable for pests control.