滴滤式砂滤池水力特性初步研究

Preliminary study on hydraulic characteristics of sprinkler sand filter

为增强砂滤池过滤性能,探究散水滴滤式砂滤池水力特性,掌握其过水规律,以石英砂为滤池填充滤料,通过物理模型试验,研究饱和砂层散水滴滤模式下滤料粒径、滤层厚度对砂滤池过水流量的影响,建立了关系曲线及函数表达式。结果显示:滤层厚度为0~4 cm时,砂滤池中出水量约由100 cm^3/s增加到600 cm^3/s;砂滤池过水流量与滤层厚度呈单调递增关系,滤料粒径越大,流量增长越快;砂滤池过水流量与滤料粒径呈二次函数递增关系;滤层厚度大于40 cm,以粒径为5~6 mm石英砂作为滤料的砂滤池,过水流量约稳定在410~420 cm^3/s;以粒径为7~8 mm石英砂作为滤料的砂滤池,过水流量稳定在640~650 cm^3/s;粒径为1~2 mm与粒径为3~4 mm对应的流量曲线较为接近,且均随滤层厚度递增。在滤层厚度恒定条件下,增大石英砂粒径,滤池中的过水流量也逐渐增加,且不同滤层厚度对应的流量曲线平行递增。试验得出的砂滤池过水流量与滤料粒径、滤层厚度的拟合曲线可为砂滤池的设计、建造及滤料选择提供理论参考。

In order to improve the performance of sand filter,explore the hydraulic characteristics of sprinkler sand filter and understand the special rules of water flow,effects of particle size and thickness on flow under sprinkler filter mode of saturated sand layer are studied through physical model experiment with quartz sand as filler,and relation curve and function expression are created.Results show that when the filter layer thickness is0-4cm,the water flow in sand filter increases from about100cm3/s to600cm3/s;the flow and thickness present a monotonic increasing relation,and the larger the particle size is,the faster the flow increases;the flow and particle size present a quadratic function increasing relation;when the thickness is above40cm,for sand filter with quartz sand of particle size5-6mm as filler,the flow is stabilized at about410-420cm3/s;for sand filter with quartz sand of particle size7-8mm as filler,the flow is stabilized at640-650cm3/s;for particle size of1-2mm and3-4mm,corresponding flow curves are close,and both increase with the thickness.When the thickness is constant,with increase of particle size of quartz sand,the flow in the filter also increases gradually,and corresponding flow curve at different thickness increases in parallel.The fitting curve of flow,particle size and thickness of sand filter obtained from the experiment may provide theoretical reference for the design and construction of sand filter and the selection of filter material.