粒状滤料过滤理论浅析

粒状滤料过滤理论的主要内容是过滤机理、过滤方程式和反冲洗机理。过滤机理有悬浮颗粒的迁移机理、悬浮颗粒的吸附机理和脱落机理等。过滤在水澄清的同时，滤层的水头损失增加，整个过程涉及因素多而且复杂，过滤方程式很难得到解析性的答案，所以过滤方程对过滤过程只起定性的作用。现在反冲洗机理的研究认为，悬浮颗粒从滤料表面脱落是水流剪切和颗粒碰撞综合作用的结果。

Primary Study on Filtration Theory of Grainy Filtering Media

The main content of filtration theory of grainy filtering media consists of filtration mechanism, filtration equation and backwashing mechanism. The mechanism of filtration includes migration, adsorption, shedding of suspending grain, etc. In the process of filtration, head loss increases when water is clarified. The whole filtration relates to many complications. It is difficult to analyze the process of filtration by filtration equations. So filtration equations only determine the nature of filtration process. Now backwashing mechanism considers that the suspending grains fall from the surface of filtration media on account of current cutting and grains collision.