The common multi-media filters used in water treatment are anthracite quartz sand magnetite filter, activated carbon quartz sand magnetite filter, activated carbon quartz sand filter, quartz sand ceramic filter, etc.

多介質(zhì)過濾器的濾層設(shè)計(jì)，主要考慮的因素為：

The main factors to be considered in the design of multi-media filter are as follows:

1、不同濾料具有較大的密度差，保證反洗擾動(dòng)后不會(huì)發(fā)生混層現(xiàn)象。

1. The density difference of different filter media is large, which can ensure that there will be no mixing layer after backwashing disturbance.

2、根據(jù)產(chǎn)水用途選擇濾料。

2. The filter material is selected according to the purpose of producing water.

3、粒徑要求下層濾料粒徑小于上層濾料粒徑，以保證下層濾料的有效性和充分利用。

3. The particle size of the lower filter material is required to be smaller than that of the upper filter material to ensure the effectiveness and full utilization of the lower filter material.

事實(shí)上，以三層濾床為例，上層濾料粒徑，有密度小的輕質(zhì)濾料組成，如無煙煤、活性炭；中層濾料粒徑居中，密度居中，一般為石英砂組成；下層濾料由粒徑更小，密度的重質(zhì)濾料組成，如磁鐵礦。由于密度差的限制，三層介質(zhì)過濾器的濾料選擇基本上是固定的。上層濾料起粗濾作用，下層濾料起精濾作用，這樣就充分發(fā)揮了多介質(zhì)濾床的作用，出水水質(zhì)明顯好于單層濾料的濾床。而對(duì)于飲用水，一般禁止使用無煙煤，樹脂等濾料。

In fact, taking the three-layer filter bed as an example, the upper filter material has the largest particle size and is composed of light filter materials with low density, such as anthracite and activated carbon; the middle filter material has a medium particle size and a medium density, which is generally composed of quartz sand; the lower layer is composed of heavy filter material with the smallest particle size and the largest density, such as magnetite. Due to the limitation of density difference, the selection of filter material for three-layer media filter is basically fixed. The upper filter material plays the role of coarse filtration, and the lower filter material plays the role of fine filtration, thus giving full play to the role of multi-media filter bed, and the effluent quality is obviously better than that of the single-layer filter bed. For drinking water, it is generally forbidden to use anthracite, resin and other filter materials.

多介質(zhì)過濾器主要由過濾器體、配套管線和閥門構(gòu)成。

The multi-media filter is mainly composed of filter body, matching pipeline and valve.

其中過濾器體主要包括以下組件：簡(jiǎn)體；布水組件；支撐組件；反洗氣管；濾料；排氣閥(外置)等。

The filter body mainly includes the following components: cylinder; water distribution component; support component; backwashing gas pipe; filter material; exhaust valve (external), etc.

濾料的選擇依據(jù)

Selection basis of filter material

(1)必須有足夠的機(jī)械強(qiáng)度，以免在反沖洗過程中很快地磨損和破碎；

(1) It must have enough mechanical strength to avoid rapid wear and breakage in the process of backwashing;

(2)化學(xué)穩(wěn)定性要好；

(2) The chemical stability is good;

(3)不含有對(duì)人體健康有害及有毒物質(zhì)，不含有對(duì)生產(chǎn)有害、影響生產(chǎn)的物質(zhì)；

(3) It does not contain harmful and toxic substances to human health, and does not contain substances harmful to or affecting production;

(4)濾料的選擇，應(yīng)盡量采用吸附能力、截污能力大、產(chǎn)水量高、出水水質(zhì)好的濾料。

(4) The selection of filter media should try to use the filter materials with high adsorption capacity, pollution interception capacity, high water yield and good effluent quality.

在濾料中，卵石主要是起支撐作用，在過濾工藝過程中，因其強(qiáng)度高，相互之間的間距縫隙穩(wěn)定，孔隙大，便于正洗工序中，濾后水順利通過；同樣，反洗工序中，反洗水和反洗空氣等能順利通過。常規(guī)配置中，卵石分為四種規(guī)格，鋪墊方式為自下而上先大后小。

In the filter material, pebbles mainly play a supporting role. In the process of filtration, due to its high strength, stable spacing, and large pores, it is convenient for the filtered water to pass smoothly in the forward washing process; similarly, in the backwashing process, the backwashing water and air can pass smoothly. In the conventional configuration, the pebbles are divided into four specifications, and the paving mode is from bottom to top, first large and then small.