Assessment of spray characteristics by studying the effect of nozzle sizes,  air-assisted speed and their interaction

The efficiency of spray applications in agricultural fields is directly affected by nozzle characteristics and sprayer operating parameters. This work investigates the optimization of a comment spray nozzle characteristics in laboratory conditions by testing the effect of different nozzle sizes and air-assisted speeds on the spray pattern including spray width, spray angle, and accumulated amount of spray deposited on the target zone. Four flat fan nozzle sizes (0.3, 0.5, 0.6, and 0.8) and three air-assisted speeds (3.5, 6.5, and 9.5 m s-1) were used. All measurements were performed at the working pressure of 2 bar and a spraying height of 25 cm. Collected data were analyzed using factorial experiments using a completely randomized block design. To test the significance differences between the treatments studied, the least significant difference (L.S.D.) test at the 0.01 probability level was used. Preliminary results showed a significant difference of nozzle size, air-assisted speed, and their interactions on spray characteristics. A larger flat fan nozzle size (0.8) generally produces wider spray patterns. Whereas, the air-assisted speed increases by 9.5 m.s-1 enhances the dispersion of spray droplets, resulting in wider coverage, affected by the result of accumulated spraying, and reducing the deposition efficiency on the grooves of the accumulated liquid collection device. However, the optimal spray width (0.65m) and spray angle (52°) for maximum spray volume (1.6 L.min-1) are achieved when these factors are carefully balanced at nozzle size (0.6) and air assistance speed (6.5 m.s-1). The results of this study provide a comprehensive analysis of how varying these factors affect the spray features and provide practical guidance for optimizing spray characteristics to achieve desired results in different spray applications. The results underscore the importance of selecting nozzle size and air-assisted speed settings for the specific operating conditions to enhance spray effectiveness and efficiency