Using Variable Spray Angle Fan Nozzle on Long Spray Booms

Abstract

Abstract. A new-concept of using variable spray angle fan spray nozzle in conjunction with pulse width modulation technique was proposed for compensation of the effects of spray boom vibration on chemical application rate and pattern. A brief review of literature regarding techniques used to diminish the effects of long spray booms dynamic behavior on uniformity of spray application reveals that the research work so far has mostly been involved boom positioning, vibration analysis, mathematical modeling and monitoring of boom dynamic behavior, in the hope of finding the ways of attenuation of vibration through improving the design of better boom structure, suspension, and control systems. The present article puts forward the idea of using Variable Spray Angle Fan Spray Nozzle (VSAFSN) along with pulse width modulation (PWM) technique to maintain constant spray coverage, hence, uniformity of spray application while employing variable rate technology (VRT). TEEJET-XR11002 Nozzle was used and preliminary experiments were carried out. Spray pressure range of 55 kPa to 490 kPa, was used to vary spray angle from 78 to 160 degrees. Results showed that the spray maintained its almost normal distribution pattern within full range of spray angle. Relationships between spray angle and operating pressure, and, between spray angle and nozzle flow rate were found as  and  respectively. Keywords: Spray, Boom, Nozzle, Pulse width modulation