Experimental study on characteristics of laminated sand filter for micro-irrigation

Based on irrigator blocking problem for micro-irrigation, lamination sand filter was studied and designed by analyzing the existing sand filters. Through a great number of tests on hydraulic characteristics, experiments of characteristics of reverse-flushing and anti-blocking and control experiments, the optimum number of lamination was discussed and determined: with fixed diameter Φ₁=20 mm, the optimum lamination number is 48. The property curve equation of hydraulic characteristics and an empirical equation of head-loss of filtering were put forward. The experiments showed that laminated sand filter was of better hydraulic characteristics with bigger filtering capacity and smaller head-loss. With specified flow 10 m³/h, differential pressure of laminated sand filter was 37% smaller than that of filter-head sand filter; with effective filtering and reverse-flushing performance, laminated sand filter was optimum anti-blocking equipment for water-saving irrigation.