Effect of Nozzles design on the performance of Impact Sprinklers in sprinkler irrigation system

Abstract

Water is limited resource. This is considered to be one of the main challenges for future water policy. Saving water and energy is a requirement to ensure the viability of pressurized irrigation systems. Designing and optimizing sprinkler irrigation systems are mainly based on achieving appropriate hydraulic performance. Spray nozzles being very often a critical component in determining the final quality of the product or the sprinkler irrigation efficiency process. The engineering design factors of sprinkler affect sprinkler system performance. So, this study focuses on some engineering design factors (three different nozzle characteristics (1, 2 and 3) and operating pressures from 150 to 250 kPa), comparing with designed nozzle (No 4) to improve brass impact sprinkler performance. This study sited on Giza region at National Laboratory for testing the components of irrigation networks and field drainage, Agricultural Engineering Research Institute AEnRI, Agricultural Research Center ARC. The result of Christiansen uniformity coefficient CU indicated that designed nozzle No 4 achieving good performance according to American society of Agricultural and Biological Engineers ASABE 2001 starting with operating pressure 150 kPa 74.05 % while nozzle No 3 starting with 175 kPa achieved 75.23 %. Also it was found that nozzle No 4 increasing flow rate by 43.48 %, precipitation rate by 19.92 %, rotation speed by 24.96 %, decreasing coverage radius by 28.38 % and the jet breaks up sufficiently to achieve an adequate water distribution pattern and obtained good droplet size comparing with nozzle No 3. It was found that sprinkler layouts 9m Х 9m overlapping achieved acceptable uniformity at operating pressure 150 kPa. Also the result indicated that nozzle No 4 saved operating time ratio by 26.87 % and decreased over minimum application targeted irrigation depth by 66.7 % at the same overlapping distances and at the same operating pressure 150 kPa.