Effect Of Emitter Structure And Type On Emitter Clogging

Drip irrigation is the most water-saving modern precision irrigation technology in agricultural irrigation,which has the advantages of water saving,energy saving,high automation,increasing crop yield,time saving and labor saving,and can effectively alleviate the contradiction of agricultural water use in arid and semi-arid area.The emitters are the core part of the drip irrigation system.It can evenly and stably drip into the soil after dissipating the pressure water through the complex narrow channel structures.However,due to the high sediment concentration of surface water and other muddy water,it is easy to block the emitters of the drip irrigation system,thus affecting the irrigation efficiency and limiting the popularization and use of drip irrigation technology.At present,there are many researches about the influence of water quality and working pressure on emitter clogging,but few reports about the influence of and emitter type on emitter clogging.In order to find out the influence of emitter channel structure and emitter type on the clogging process of emitter in muddy water drip irrigation system.In this study,one non pressure compensated inlaid drip band E4,three non pressure compensated inlaid cylindrical drip bands E1,E2,E3 and three pressure compensated inlaid drip bands E5,E6,E7 were selected,and two kinds of muddy water were configured for periodic intermittent irrigation test.It provides a theoretical reference for the practice of muddy water drip irrigation in the Yellow River Diversion Irrigation Area,the optimization design of different types of dripper channel structure and the use of drip irrigation belt under different water quality conditions in the same area.The main conclusions are as follows:?1?The emitter channel structure is the main factor that affects the anti clogging performance of different types of emitter,and the minimum cross section is the most critical structural parameter of emitter.The clogging degree of different types of drippers increases with the decrease of the minimum cross section of drippers.When the minimum section size of the dripper is more than 0.73mm,the dripper did not block after two kinds of muddy water tests.?2?the emitter channel structure have an important impact on the quality of the clogging mass.After the muddy water 2 test,the plugging mass of cylinder emitters and pressure compensation emitters were 0.0185-0.0668g and 0.0056-0.0267g,respectively.Among them,the plugging mass of E3 in cylinder emitters was significantly different from that of E1 and E2.With the increase of the minimum cross-section of the dripper,the plugging mass of the cylinder dripper and the pressure compensating dripper decreases,but with the increase of the length of the dripper channel.?3?The dripper type is an important factor affecting the dripper blocking.The structure coefficient of dripper can be used as an important index to measure the anti blocking performance of different types of dripper.The anti blocking performance of dripper increases with the increase of structure coefficient.When the structure coefficient is the same,the relative flow of two kinds of cylindrical drippers is greater than that of pressure compensating drippers.When the structure coefficient is 2%,the relative flow of two kinds of cylindrical drippers is 91.66%and 79.63%respectively,while the relative flow of pressure compensating drippers is only 75.84%and 65.08%.The anti clogging performance of dripper can not only be judged by pressure compensation,but also by considering the type of dripper,structure coefficient of dripper and water quality.?4?With the increase of irrigation times,the pressure compensating dripper is more likely to block the whole dripper than the cylinder dripper.When the structure coefficient is not less than 1%,the slope of the correlation curve of the relative flow rate and irrigation uniformity of the cylindrical emitter is greater than 1,while that of the pressure compensating emitter is less than 1.The fitting straight-line slopes of the cylindrical emitter D_raand Cu are 1.14,1.41 and 0.65,respectively,and that of the pressure compensating emitter is 0.41,0.82,0.81 and 0.45,respectively.The capillary with cylindrical dripper is easier to deposit sediment and reduce sediment entering into the dripper,while the capillary with pressure compensating dripper is relatively difficult to deposit in the capillary,and more sediment is easily discharged from the capillary through the dripper channel.?5?With the increase of the structure coefficient,the mass of different kinds of drippers decreased,and the structure coefficients of cylinder drippers and pressure compensating drippers were E1,E2,E3 and E4,E5,E7 and E6,respectively,while the mass of drippers was E3,E2,E1 and E6,E7,E5 and E4,respectively.