微灌砂滤料的表层过滤和气水反冲洗试验研究

Surface Filtration and Air-Water Backwashing for Sandy Filter Media in Micro-irrigation

采用砂过滤器模型,在3种滤料粒径的条件下进行了过滤和气水反冲洗试验研究。根据在不同的过滤速度、原水颗粒质量分数、粉煤灰粒径条件下测得的滤层表面的压力,判断各因素与发生表层过滤的关系。以出水浊度随时间的变化,对比3种加气模式以及单纯水洗的效果。试验结果表明,原水颗粒质量分数和煤灰粒径是发生表层过滤的主要影响因素,且砂滤料的粒径越小,越容易发生表层过滤,在一定速度范围内过滤速度的影响最小。反冲洗以出水浊度为指标,气冲-气水混冲-水冲与气水混冲-水冲要优于气冲-水冲和单纯水洗的效果。

Using sandy filer model, the experiment of filtration and air-water backwashing were carried out under three different particle sizes. Under different filtration rates, raw water mass fractions and soot par-tiele sizes, the relationship between the factors and surface filtration was determined by surface water pres- sure tested in the experiment. The effects of three filling patterns and single water backwashing were com- pared by the change of water turbidity following time. Results showed that raw water mass fraction and soot particle size were major factors leading to surface filtration. The smaller of sandy particle size, the more prone to surface filtration. Filtration rate was not a major factor under a certain speed range. Water turbidity was used as the indicator in the backwashing experiment, finding that air-air water-water and air water-water were superior to air-water and single water backwashing.