Reserch On Material And Structual Design Of Design Of Pressure Compensating Emitter

Properties of emitter is an important indicator of emitter. Complex construction of pressure compensating emitter makes it with more manufacturing deviation coefficient, higher production cost and poor anti block ability. In addition, it only Consider the influence of structural parameters on hydraulic characteristics of emitter. According to the study of pressure compensating emitters, we have found that hydraulic properties of different materials in the production of the same emitter have large differences. So from the design parameters of hydraulic characteristics of emitter, this study uses emitter hydraulic performance optimization, material properties as a starting point, to design a new type of pressure compensating emitter structures. Using Pro-E software I make out the three dimensional mapping of emitters, using irrigation laser rapid prototyping I make the test specimens and test hydraulic properties of emitters. Moreover foul the short cycle test for testing the water resistance performance. And open mode for optimum structural parameters of irrigation, use different materials to produce the best emitter and test its hydraulic performance. Finally we select a best combination of emitter structures and materials. The main conclusions are as follows:(1)Design a-pressure compensating emitter consisting of cover, gasket and base constitutes, having the advantage of simple knots and good compensation. Range of emitter’s compensation is 10-38 m, flow exponent is 0.065 and rated flow rate is 14 l/h, deviation coefficient of Emitter flow rate is below 0.07, meeting regulatory requirements all;(2)With analysis of SPSS, I find out that minimum flow control make a great difference on emitter flow rate, flow depth and compensation range. Thickness and hardness of Gasket make a difference on the flow. Therefore, when designing this type of emitter, we must consider the minimum flow control depth of irrigation and selection of gasket thickness and hardness. Optimum hydraulic performance parameters of the emitter are as follows: 0.5 mm minimum flow control depth, 23 pad Hardness, 1.7 mm shim thickness;(3)According to the text, the pressure range of pressure compensating emitters is 10-38 m, emitter flow rate deviation coefficient is all below 0.07, meeting regulatory requirements. Simple structure of the emitters is a major factor of flow deviation coefficient;(4)Anti-blocking experiment in short period, this study measured that emitter flow and percentage of rated flow is always higher than the emitters plug flow critical value for 75%. And the emitter has not been blocked and meet the blocking requirements. The emitters are with simple structure. We can use a broader range of water for irrigation. And filter requirements are relatively low, improving the promotion of the emitter greatly;(5)In actual use, material parameters make a larger influence on the hydraulic characteristics of emitter,comparing with uniformity and variation, pressure-flow parameters and other optimal for the pressure-compensated irrigation. I find out that the best material is ABS. pressure compensating emitter using ABS material has performance welding, long service life, correspond to the hydraulic characteristics of the emitter using photosensitive resin production and experimental phase : pressure compensated range is 6-38 m, flow exponent is 0.087, rated flow is 12 L/h;...