In the process of water treatment, filtration generally refers to the process of using quartz sand, anthracite and other granular filter material layer to intercept suspended impurities in water, so as to make water clear. The main function of filtration is to remove the suspended colloidal impurities in water, especially the micro particles and bacteria that can not be removed by precipitation technology. BOD5 and COD also have a certain degree of removal effect. In the industrial circulating water treatment system, the multi-media filter is used to remove the impurities in the sewage, adsorb oil, etc., and make the water quality meet the requirements of recycling.

(1)濾料的機械強度一定要好防止在反衝洗過程中很快地破碎和磨損；

(1) The mechanical strength of the filter material must be better to prevent it from breaking and wearing quickly in the backwashing process;

(2)濾料的化學穩定性要好

(2) The chemical stability of filter material is better

(3)配套管線和閥門。其中多介質過濾器體又包括①簡體；②反洗氣管；③布水組件；④支撐組件；⑤濾料；⑥排氣閥(外置)等。

(3) Matching pipelines and valves. The multi-media filter body also comprises a cylinder body; ② Backwash the trachea; ③ Water distribution components; ④ Support components; ⑤ Filter media; ⑥ Exhaust valve (external), etc.

過濾器體；濾料的選擇依據：濾料不應該含有對人體健康有害的有毒物質，不應含有影響k8凯发官网入口，對k8凯发官网入口有害的物質；

Filter body; The selection basis of filter material: the filter material should not contain toxic substances harmful to human health and production;

(4)濾料的選擇，應盡量采用吸附能力、截汙能力大、產水量高、出水水質好的濾料。其中的卵石，主要是起支撐作用，在過濾工藝過程中，因其強度高，相互之間的間距縫隙穩定，即孔隙大，便於正洗工序中，濾後水順利通過；反之反洗工序中，反洗水和反洗空氣等順利通過。常規配置中，卵石分為四種規格，鋪墊方式，先大後小。

(4) The selection of filter materials should try to use the filter materials with high adsorption capacity, high sewage interception capacity, high water yield and good effluent quality. In the process of filtration, because of its high strength, the gap between them is stable, that is, the pores are large, which is convenient for the smooth passage of filtered water in the washing process; On the contrary, in the backwashing process, the backwashing water and air pass smoothly. In the conventional configuration, the pebbles are divided into four specifications, and the paving method is large first and then small.

濾料的粒徑和裝填高度之間的關係：濾床的高度和濾料的平均粒徑的比值為800～1ooo(設計規範)。濾料的粒徑的大小和過濾精度相關。

The relationship between the particle size of filter media and the loading height: the ratio of the height of filter bed to the average particle size of filter media is 800 ~ 1OOO (design specification). The particle size of filter media is related to the filtration accuracy.