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ARS Home » Midwest Area » Wooster, Ohio » Application Technology Research » Research » Publications at this Location » Publication #407512
Research Project: Coordinated Precision Application Technologies for Sustainable Pest Management and Crop Protection

Location: Application Technology Research

Title: Flow rate modulation capability and droplet size spectrum of an air-piloted PWM pinch valve coupled with hollow-cone nozzles

Author
item CAMPOS, JAVIER - The Ohio State University
item Zhu, Heping
item Jeon, Hongyoung
item SALCEDO, RAMON - Technical University Of Catalonia
item ROMAN, CARLA - The Ohio State University
item OZKAN, ERDAL - The Ohio State University

Submitted to: ASABE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: 9/20/2023
Publication Date: 10/20/2023
Citation: Campos, J., Zhu, H., Jeon, H., Salcedo, R., Roman, C., Ozkan, E. 2023. Flow rate modulation capability and droplet size spectrum of an air-piloted PWM pinch valve coupled with hollow-cone nozzles. ASABE Annual International Meeting. ASABE Paper No. 2300363.

Interpretive Summary:

Technical Abstract: Electrically controlled pulse width modulation (PWM) solenoid valves are commonly used to manipulate nozzle flow rates to achieve precision variable-rate spray applications. However, some pesticide compositions such as wettable powders have the potential to be stuck in the valve chamber if spray lines are not cleaned well after spray applications, causing malfunctions of the flow modulation. An air-piloted PWM pinch valve was evaluated to manipulate flow rates of hollow-cone nozzles. With this valve, spray solutions only passed through a pinched tube to avoid the pesticide fluid directly contacting the internal chamber. The flow rate modulation was performed by pinching the tube with air-piloted PWM actions so that the internal moving components were isolated from pesticides. Tests were conducted to evaluate the flow rate modulation capability along with droplet size spectra of disc-core hollow-cone nozzles coupled with the PWM pinch valve and compared with a conventional electrically controlled PWM valve. Nozzles were Teejet D2-DC25, D4-DC25, and D5-DC25, operated at 414 and 827 kPa pressures and duty cycles ranging from 10% to 100% with 10% intervals. Flow rates were measured with the instantaneous mass of discharged water for 60 seconds, and the droplet size spectra were determined with a laser particle/droplet imaging analysis system. In general, the air-piloted PWM pinch valve performed similar to the conventional PWM valve with respect to the flow rate modulation accuracy and droplet size spectrum. Thus, it could be potentially used as an alternative PWM valve to apply pesticides with specific formulations such as wettable powders and sticky agents.