Study On The Hydraulic And Anti-clogging Performance Of Emitters

Emitters are one of the key parts of drip irrigation system. Thus, the study on the hydraulic performance and anti-clogging ability of emitters has important significance. The content and results analysis in this paper conclude the following four parts: (I) An equipment for testing the hydraulic performance and anti-clogging performance of emitters has been developed. This equipment can test the emitters' hydraulic performance, which includes the relationship between pressure and flow rate, the impact on flow rate by water temperature, manufacturer's coefficient of variation of emitters. It also can test the emitters' anti-clogging ability, which comprises physical clogging and chemical clogging. (2) Hydraulic performance of seven typical emitters forms were studied under different flow passage length respectively through experiments. The exponent of flow state of these emitters was compared. Under the same working pressure and flow rate, the flow passage length and cross-section area of the seven different emitters were compared. According to those results, the anti-clogging ability of emitters was analyzed and several good structural form of flow passage were obtained. In addition, regression model describing the relationship among flow rate, the length of flow passage and work pressure was set up. (3) Quadrature experiment consisted of four experimental factors including dental angle, space between dental structure, dental height and the depth of flow passage of dentate, any one of which has four different values. How these dental structural parameters affected hydraulic performance of dentate emitters was studied. The optimal combination among structural factors was obtained through experimental results. In addition, which experimental factor has significant influence on the exponent of flow state and flow rate of these emitters was analyzed. Finally, several regression models describing the relationship between flow rate and structural parameters of flow passage were set up under the condition of certain flow passage length and 10m working pressure. (4) Anti-clogging experimental scheme was established on the basis of referring to ISO Anti -clogging experimental scheme which is still under discussion. How these structural parameters affected anti -clogging ability of dentate emitters was studied. According to the test results, the optimal combination among structural factors was obtained and which structural factor has significant influence on the anti -clogging ability of these emitters was analyzed. Furthermore, the relationship among flow passage width, flow rate of emitters and anti -clogging ability of dentate emitters was analyzed. (5) Finally, an enlarged emitter model was designed according to hydraulic engineering model principle, which was used for exploring hydraulic similarity between the original model and the enlarged model.