滤层配置特征对砂滤池过滤性能的影响

Effect of filter media configuration characteristics on the performance efficiency in quartz sand filter

滤料粒径、层厚和颗粒分布等滤层配置特征,是保证滤池高效运行的关键因素之一.根据实际应用构造了三种典型的模拟滤层,进行系统的过滤对比试验,研究滤层构造特征对过滤性能的影响.试验结果表明,均质滤料滤层在水头损失增长率、滤后水平均浊度、颗粒物截留效果、滤层产水率以及过滤性能指标F值等多个方面具有优势;滤后水颗粒物截留效果主要决定于滤层厚度,与滤层厚径比L/d值没有相关性;砂滤层对于水中2-5μm之间的颗粒物截留效果差;＂细粒径、浅滤层＂的滤层配置尽管避免了过滤末期浊度值的上升,但存在水头损失增长率大、滤后水平均浊度高、残留颗粒总数大等弊端,采用＂深滤层、均质滤料＂的滤层配置方式应是今后水厂滤池设计和技术改造的主要技术措施。

The particle size,bed depth and configuration of filter media play a key role in filtration process.Based on the practice,three typical monomedium sand configurations were selected to conduct performance comparison with several focuses.The results revealed that homogeneous sand media have some advantages in head-loss increasing control,filtered water average turbidity,particles removal efficiency,filter net production ratio and performance index F value.The particle count control depended on the bed depth mainly,and the effect of filter media equivalent depth L/d on particle removal was proved.The particles with size 2-5 μm was the most groups difficult to remove with sand filter.The less size and depth of media configuration means higher head loss increasing,higher filtered water turbidity and particles count,although this configuration could avoid the detrimental effect from turbidity increasing at the end of run.All of above,the media configuration with deeper bed depth and more uniform size distribution along depth should be regarded as the prior alternative choice for filter design and prompting in the future.