Design and development of a dual purpose unloading valve for power operated sprayers

Design and development of a dual purpose unloading valve for power operated sprayers

Agricultural production in India has been able to keep pace with the ever increasing population and maintain food security. Consequently, several new and improved equipment have been introduced in agriculture to increase the yield and to save valuable inputs in farm. Among various types of sprayer in use, a power operated sprayer becomes more and more popular with unavailability of labour, less time available for pesticide spraying and availability of improved and advanced power operated sprayers. Power operated sprayers are equipped with the pressure relief valve to protect the system from overload and maintain constant pressure relief valve runs the power source continuously on load. This leads to undue loss of power when system is not operating as during turning and orchard spraying. Test results of the ASPEE control valve proved that there was no significant variation in power consumption on load as well as on unload. In addition, it requires modifications as pressure fluctuations was observed at all pressure levels that is not feasible for spraying. At recommended operating pressure of 1.4 Mpa, overall efficiency was around 35 percent for both nozzles on load and unload. Operating parameters for the DPU-valve were fixed from the control valve testing. A new DPU-valve was designed for maximum pressure of 2.8 Mpa and discharge of 36 1/min. Test results of the DPU-valve with three pumps, HSP (discharge 12 1/min and maximum pressure 2.8 Mpa with 1 hp power consumption), HDP (discharge 36 1/min and maximum pressure 2.8 Mpa with 2 hp power consumption), and HTP (discharge 36 1/min and maximum pressure 2.8 Mpa with 3 hp power consumption) showed that power consumption on load and unload was as high as 1.7 Kw for HTP. Pressure fluctuation was observed for HSP and HDP beyond 2.1 Mpa pressure. This may be due to over design of the orifice area as it was designed for discharge of 36 1/min. Operating pressure remained constant at all pressure levels for HTP. Overall efficiency for both ASPEE control valve and DPU-valve was independent of the type of nozzle and increases at decreasing rate with increase in pressure. In addition, overall efficiency was observed nearly same on load and unload.


Agriculture Sprayers and Dusters by ASPEE Group Of Companies, India.

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This article is written by Shri. Pravin Sopan Barhate of Indian Institute of Technology, Kharagpur on behalf of ASPEE Agriculture Research and Development Foundation. ASPEE Group of Companies is the leading manufacturer and exporter of Agriculture Sprayers and Dusters


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