Study On Water And Sand Performance Of Swirl And Screen Type Combined Filter

Filter is the key device to ensure the stable operation of the micro irrigation system.As the core of micro-irrigation systems, its importance has become increasingly prominent.The economic benefits has also been widespread concerned in the community.How to prolong the stable operation time and improve the adaptability of filters become the main direction of research and development.In this paper, based on the indoor experiment, do analysis to the hydraulic characteristics and sediment processing capabilities for spin-drift type combined filter. The main research achievements are:(1)On the basis of the swirl filter and screen Filter,do analysis to the factors of head loss, influencing factors, adaptability and the possibility of combined, through the indoor test and field investigation, make the parameters which influenced the combined filter hydraulic performance and the filtration performance as a variable experiment to carry out. Under clear water conditions, measuring the pressure gauge data of the combined filter which working under different conditions,can find out the value of local head loss under non-blocking conditions.Draw Chart which shows the relationship about time and head loss depending on the experimental data, the semi empirical formula of the head loss is given. From the text of the clear water conditions that the head loss of the combined filter was decided by flow and structure parameters of the filter. And the trend is intensifying.Under the muddy water conditions,through regulating the flow and sand ratio,do analysis to the hydraulic performance of the combined filter,with the sand ratio grow,the time gradually shortened.(2)By drawing the combined filter head loss curves, analyze the characteristics of water conservancy. Experiments show that under the condition of high flow, compared the combined filter with the traditional single screen filter, pressure drop curves for double section type, means two stages of stable series.And the inflection point of head loss which takes great increase come out lately.When the first inflection point appears, the head loss grows in a small rang, then tended to be stable. At that time the water flow reduce to the set water flow’s 85-90%.When the second inflection point occurs, the flow is reduced of the set water flow’s 15-20%. Under the condition of low flow rate, the combined filtering device doesn’t use the swirl filter completely. Not like in the case of high flow formation changed two times,the filtration characteristics of the hydraulic performance shows for single point.When the inflection point appears,turn off the button and observe the screen, Find the inflection point time come out when 50% and 92% filter area be blocked.(3)According to the parameters of centrifugal force field intensity, and the separation efficiency of swirl filter,do analysis on the various components in the process of filtering effect,and contrast on the filtration performance.Experiment shows that compared to single type swirl filter and screen type filter, the combined filtering device can block solid particle impurities effectively, which has enhanced the filtering performance.At the same time, for the installation of Swirl filter, the pressure filtration of the screen type filter greatly reduced.During the experiment, weighing the solid particle impurities in the cyclone filter’s sand storage tank and screen filter,and do the grain size test respectively.At the same time, do analysis to filtration performance factors and adaptability when facing different conditions of Feasibility and disadvantages of the combination.According to the initial value of the filter’s head loss and the flow range of the swirl filter, determining the optimal conditions of combined filtering device is 100-140 m3/h, have the guiding significance for engineering application.