不同滤网条件的微压过滤冲洗池过滤性能研究

Filtration performance of micro-pressure filtering and washing pool with different screen materials

为探讨微压过滤冲洗池采用不锈钢和腈纶滤网作为过滤元件的过滤性能,以过滤时间、拦截泥沙质量及泥沙去除率为评价指标,在水流含沙量为0.66 kg/m3和流量为5.0 m3/h条件下分别开展了物理模型试验。试验结果表明:在水箱水深变化方面,腈纶滤网存在水深恒定、水深快速增加及水深急速增加3个过滤阶段,而不锈钢滤网没有水深急速增加阶段;两种滤网的水深恒定时间相差不大,但不锈钢滤网的过滤时间略大于腈纶滤网;腈纶滤网拦截泥沙质量大于不锈钢滤网,且腈纶滤网能拦截到更小粒径的泥沙;腈纶和不锈钢滤网的泥沙去除率分别为61.10%~83.50%和44.00%~62.05%,前者是后者的1.35~1.42倍。综合考虑各项指标认为腈纶滤网更适用于微压过滤冲洗池,试验成果可为微压过滤冲洗池的深入研究提供理论依据和技术支撑。

In order to explore the filtration performance of the elements with stainless steel and acrylic filter screen in the pool of filtering and washing under micro-pressure( PFWMP),physical model tests were carried out with the flow rate under 5 m^3/h and the sediment concentration of 0. 66 kg/m^3. Filtration time,quality of intercepted sediment and sediment removal rate were selected as the evaluation indexes.As it is shown in the result,filtration performance of the two filter screens are different. There are three filtration stages with acrylic filter screen,i. e.,constant water depth,rapid increase of water depth and sharp increase of water depth,whereas there is no sharp increase of water depth with stainless steel filter screen. The constant time of the water depth of the acrylic filter screen and the stainless steel filter screen is not much different,but the filtration time of the stainless steel filter is longer than that of the acrylic filter screen. Furthermore,the quality of the sediment intercepted by the acrylic filter screen is better than that of the stainless steel filter screen with a finer particle size. The sediment removal rate of acrylic filter screen and stainless steel filter screen are 61. 10%-83. 50% and 44. 00%-62. 05%,respectively,the former is 1. 35-1. 42 times of the latter. So,acrylic filter screen is selected as the filtration core element of the PFWMP after comprehensive consideration of various indexes. The test results can provide theoretical basis and technical support for the further study of the PFWMP.