An automatic pressure control system for precise spray pattern analysis on spray patternator

Abstract

A study was carried out to develop an automatic pressure control system to regulate the spray pressure of various nozzles, including Type A, Type B, and Type C nozzles. A laboratory-based hydraulic nozzle test setup was utilized to evaluate the performance of hydraulic nozzles at different operating pressures ranging from 2 to 5 kg/cm2 (196.2 kPa–490.33 kPa), with regular intervals of 0.5 kg/cm2 (49.03 kPa). Water pumping was achieved using a 12 V DC diaphragm pump. A comparison was made between the developed pressure control system and a pressure relief valve + gate valve in terms of their ability to control pressure and assess the effectiveness of the developed system. Furthermore, the impact of operating pressure on flow rate, cone angle, swath width, and spray dispersion were examined. Upon utilization of the developed pressure control system to set the operating pressure, the discharge rates exhibited less than 1 % variation across all pressure settings and repetitions. Conversely, when a pressure relief valve and gate valve were used to set the operating pressure, discharge rates for all three nozzles displayed a coefficient of variation (CV) exceeding 1 % at most set pressures. The pressure control system successfully maintained the pressure within ±0.1 kg/cm2 (±9.81 kPa) of the target pressure level. The Type A nozzle exhibited the most uniform volumetric distribution at an operating pressure of 4 kg/cm2 (392.27 kPa), with a CV of 8.52 %, which was the lowest among the three nozzles studied.