過濾器通常有進水裝置、配水系統等主要裝備，有時還有用來進壓縮空氣的裝置。在過濾器外設有各種必要的管道和閥門等。機械過濾器有罐體常用玻璃鋼、不銹鋼及碳鋼加襯防腐層制成，常用的過濾器濾料有：石英砂、大理石、無煙煤、錳砂及白云石等，其顆料直徑大約在0.5-1.5之間。過濾器內即可裝填一種填料，又可裝填兩種或三種填料。

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.

過濾器的運行是成周期性的，每個周期可分為過濾、反洗和正洗三個步驟。

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

反洗的目的是清除濾層中積累的污物，以恢復濾層的截污能力。它是過濾器運行的一個重要步驟。為了使反洗的效果良好，在反洗時還通常通入壓縮空氣。

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.

普通過濾器的運行流速約8～10m/h，當它運行到水流通過濾層的壓力降達到允許極限時，停止過濾運行，開始反洗。此時將過濾器內的水排放到濾層的上緣為止，然后送入強度為18-25L/（m2.S）的壓縮空氣，吹洗3～5min后，在繼續供給空氣的情況下，向過濾器內送入反洗水，其強度應使濾層膨脹率約達40%～50%。最后，用 水正先下至出水合格，方可開始正式過濾運行。

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.

這種過濾器，除了可以照水通過濾層的壓力降來確定是否需要清洗外，也可按照一定的運行時間，來進行清洗。其允許的運行周期，應通過調整試驗求得。過濾器不應經常在將要有懸浮物穿過的時候方進行清洗，應稍提前進行，否則濾層不易清洗干凈，長此下去會使濾料產生結塊。一般允許壓力降約為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.