Pretreatment filtration system, pretreatment filtration system, multi-media filter, quartz sand filter, activated carbon filter, resin filter tank

过滤器通常有进水装置、配水系统等主要装备，有时还有用来进压缩空气的装置。在过滤器外设有各种必要的管道和阀门等。机械过滤器有罐体常用玻璃钢、不锈钢及碳钢加衬防腐层制成，常用的过滤器滤料有：石英砂、大理石、无烟煤、锰砂及白云石等，其颗料直径大约在0.5-1.5之间。过滤器内即可装填一种填料，又可装填两种或三种填料。

The filter usually has water inlet device, water distribution system and other main equipment, and sometimes has a device used to enter compressed air. All kinds of necessary pipes and valves are set outside the filter. The mechanical filter is made of glass fiber reinforced plastic, stainless steel and carbon steel lined with anti-corrosion coating. The commonly used filter materials are quartz sand, marble, anthracite, manganese sand and dolomite. The particle diameter is about 0.5-1.5. The filter can be filled with one kind of filler and two or three kinds of filler.

过滤器的运行是成周期性的，每个周期可分为过滤、反洗和正洗三个步骤。

The operation of the filter is periodic, and each cycle can be divided into three steps: filtration, backwashing and forward washing.

反洗的目的是清除滤层中积累的污物，以恢复滤层的截污能力。它是过滤器运行的一个重要步骤。为了使反洗的效果良好，在反洗时还通常通入压缩空气。

The purpose of backwashing is to remove the accumulated dirt in the filter layer, so as to restore the interception capacity of the filter layer. It is an important step in filter operation. In order to achieve good backwashing effect, compressed air is usually injected during backwashing.

普通过滤器的运行流速约8～10m/h，当它运行到水流通过滤层的压力降达到允许极限时，停止过滤运行，开始反洗。此时将过滤器内的水排放到滤层的上缘为止，然后送入强度为18-25L/（m2.S）的压缩空气，吹洗3～5min后，在继续供给空气的情况下，向过滤器内送入反洗水，其强度应使滤层膨胀率约达40%～50%。最后，用 水正先下至出水合格，方可开始正式过滤运行。

The operating flow rate of ordinary filter is about 8 ~ 10m / h. When the pressure drop of water flowing through the filter layer reaches the allowable limit, the filtration operation will be stopped and the backwashing will start. At this time, the water in the filter is discharged to the upper edge of the filter layer, and then the compressed air with the strength of 18-25l / (m2. S) is sent to the filter. After 3-5min of purging, the backwash water is sent to the filter under the condition of continuous air supply. The strength should make the expansion rate of the filter layer reach 40% - 50%. Finally, the water is being used until the effluent is qualified before the formal filtration operation can be started.

这种过滤器，除了可以照水通过滤层的压力降来确定是否需要清洗外，也可按照一定的运行时间，来进行清洗。其允许的运行周期，应通过调整试验求得。过滤器不应经常在将要有悬浮物穿过的时候方进行清洗，应稍提前进行，否则滤层不易清洗干净，长此下去会使滤料产生结块。一般允许压力降约为0.5bar。

This kind of filter can not only determine whether it needs to be cleaned according to the pressure drop of water through the filter layer, but also can be cleaned according to a certain operation time. The allowable operation period should be obtained through adjustment test. The filter should not be cleaned when there is going to be suspended solids passing through, but should be cleaned a little in advance, otherwise the filter layer is not easy to clean, and the filter material will agglomerate in the long run. Generally, the allowable pressure drop is about 0.5bar.