Design, manufacture of spray pattern test unit and flow control of sprayer nozzles

The aim of this study was to design and to manufacture a patternator prototype of sixty channel, 120×100 cm dimensions and 80 mm channel height, spraying from a single point, adjustable the spraying height and low-cost for determining the spray pattern of the sprayer nozzles and controlling the flow uniformity, and to determine the spray pattern variables for some spray nozzles. In this patternator prototype, a measuring platform with the on-off mechanism was designed to discharge the liquid from the measure cylinder after each trials and to accelerate the pattern test. In the test unit, the spray pattern visuals on the measure platform was taken photograph, and digitized with the image processing method. After the manufacturing, the effect on the spray pattern of disc-core type hollow cone type spray nozzles with different orifice sizes (Ø1.0 mm, Ø1.2 mm, Ø1.6 mm, Ø2.0 mm and Ø2.4 mm) was investigated. The trials were replicated 40 times for each orifice diameter and conducted at a constant spray pressure of 8.0 bar and a constant spraying height of 55 cm. In conclusion, the variables skewness, kurtosis, variation coefficient (CV%), volumetric distribution uniformity (CV%) for the different nozzle intervals of 25 cm, 30 cm, 35 cm, 40 cm, 45 cm and 50 cm, nozzle spray angle and nozzle actual coverage were determined. According to the results of the multivariate statistical analysis, the spray pattern of the Ø1.2 mm and Ø1.6 mm orifice diameters was found identical, and the other nozzles were determined to be different. While the spray pattern of the nozzle of Ø1.0 mm orifice diameter was visually similar the full cone type flow, the other nozzles had bimodal distribution. The spray angle and spray coverage length of the nozzles with the orifice diameter Ø1.0 mm, Ø1.2 mm and Ø1.6 mm were found lower than the nozzle orifice diameters of which were Ø2.0 mm and Ø2.4 mm. While the orifice diameter of the nozzle increased, the skewness of the spray pattern decreased. The lowest kurtosis data was found for the nozzle of Ø1.0 mm orifice diameter. Volumetric distribution uniformity data with the lowest CV% was obtained at the 25 cm and 30 cm nozzle intervals.