Hydraulic Performance of Self-priming Mesh Filter for Micro-irrigation in Northwest China

Abstract

Using Manas riverbed sediment in Northwest China as filter media, a comprehensive study was conducted on the hydraulic performance of the mesh filter, including filtration performance and sewage performance, head loss and sewage time. Relationship among filter head loss, sewage time, flow rate, sand content, filter aperture and particle gradation was established. The results showed that at the filter aperture of 0.100 mm and the influent flow rates of 160 m3/h, 180 m3/h, 200 m3/h and 220 m3/h, the corresponding maximum head loss was 8.97 m, 11 m, 12.95 m and 15.81 m, respectively. With the increase in the influent flow rate, the head loss increased. Influent flow rate, sewage flow rate, sand content, filter aperture and particle gradation jointly affected the sewage time. The sewage time was determined to be in the range of 20–45 s. Mathematical expressions for head loss and sewage time were established through theoretical analysis and verified by the test results. The results showed that the error for the head loss and sewage time between the predicted and experimental results was less than 10%, and the regression coefficient was higher than 0.95. It has been demonstrated that the proposed equations of head loss and sewage time can be used to evaluate self-priming screen filters under various working conditions. From the results, when the sewage time was 45 s, the mesh filter can achieve a higher sewage effect and ensure the efficient operation of the next filtration cycle.