大田滴灌自清洗网式过滤器水头损失试验

Experiments on water head losses of self-cleaning screen filter for drip irrigation in field

自清洗网式过滤器是目前国内外大田滴灌应用最广泛过滤器之一,其水头损失是评价过滤器性能的关键参数。该文通过对自清洗网式过滤器清水和浑水水头损失的试验研究,重点分析了80和120目滤网对应的清水和浑水水头损失变化规律。在清水试验中,得出了2种滤网目数对应过滤流量与水头损失变化关系式;在浑水试验中,分别研究了流量一定(220m3/h)和含沙量一定(0.190g/L)条件下水头损失随过滤时间变化规律,重点研究了这2种条件下浑水水头损失的计算方法,并对2种情况下水头损失进行了计算,对各种组合条件下浑水水头损失计算公式进行了拟合,分别得到流量一定条件下10种不同含沙量和含沙量一定条件下5种不同流量的水头损失计算公式。结果表明:各公式拟合精度较高,决定系数均大于0.95,可以用于浑水水头损失计算,研究结果可为实际工程中自清洗网式过滤器水头损失的计算提供参考。

Self-cleaning screen filters were broadly applicated on domestic and foreign market, it was the key parameter of water head loss evaluation. Head loss of clean and muddy water was studied in this study, and the variation law of head loss for 80 meshes and 120 meshes was analyzed. Formulas between flow rate and head loss for two kinds of mesh were obtained through clean water experiment. Under the condition of fixed flow rate （220 m3/h） and sediment content （0.190 g/L） in muddy water experiment, the variation law between head loss and time, and the calculation method of muddy water head loss was researched. The head losses in the two conditions were calculated, and the calculation formulas of head loss in all conditions were simulated. The calculation formulas for ten different sediment contents with certain fixed flow rate and five different flow rates with certain sediment content were developed, respectively. The results showed that all formulas had high precision, and the determination coefficients of which were bigger than 0.95, which could be used to calculate head loss of muddy water. The results of this study provide reference for the calculation of water head loss of self-cleaning screen filters in actual project.