滴灌系统网式和叠片式过滤器水力性能试验研究

Hydraulic Performance of Screen and Disc Filters for Drip Irrigation

滴灌系统过滤器的性能直接影响系统正常运行及使用寿命,以网式和叠片式过滤器为研究对象,进行了不同流量下清水和3种质量浓度浑水工况下,不同目数的2种过滤器水头损失和过滤性能试验,分析了过滤器水力性能的影响因素及其相互关系。结果表明,在清水条件下,过滤器的局部水头损失hj与流量Q成正比,随着系统过流量的增加而增加;相同流量下,高目数过滤器产生的水头损失大于低目数;浑水条件下,过滤器的水头损失与系统过流量、含沙量有关。随流量、含沙量的增大,过滤器初始水头损失增大,过滤周期变短。相同条件下,叠片式过滤器的水头损失明显大于网式过滤器,除沙率高于网式过滤器,即网式过滤器水力性能优于叠网式片过滤器,叠片过滤器的过滤效果优于网式过滤器。

The normal operation and service life of drip irrigation system were directly affected by the performance of the filter. The disc and screen filter were taken as the subjects. The head loss and filtration performances experiments of two kinds of filters with different meshes were conducted under the conditions of clean water and three kinds of muddy water with different flows. Factors and mutual relations that influenced the filter＇ s hydrau- lic performance were analyzed. The results showed that under the clean water condition, the filter＇ s head loss in- creased with the increase of the flow that could be described with a quadratic parabola, head loss of filter with larger mesh number was greater when the flow rate was constant. Under muddy water conditions, the filter＇ s head loss was related to the flow variation and sediment concentration. With the increase of flow and sediment concentration, the higher the initial head loss was, the shorter the filtration cycle was. Under the same conditions, the disc filter＇ s head loss and sediment removal rate were both obviously higher than the screen＇ s. In a conclusion, the hydraulic performances of screen filters were better than the disc filter＇ s, and the sediment removal capacity of disc filter are better than screen filter.