Analytical Design Principle of Multimedia Filter

多介质过滤器是应用一种或几种过滤介质，在一定的压力下把浊度较高的水经过一定厚度的粒状或非粒资料，从而无效的除去悬浮杂质使水廓清的进程，常用的滤料有石英砂，无烟煤，锰砂等，次要用于水处置除浊，硬化水，纯水的前级预处置等，出水浊度可达3度以下。

Multimedia filter is the process of removing suspended impurities and clearing water ineffectively by using one or several filter media to pass through the granular or non-granular data with a certain thickness under a certain pressure. The commonly used filter media are quartz sand, anthracite, manganese sand, etc. Secondly, it is used for turbidity removal, hardening water and pre-treatment of pure water. The turbidity of effluent can reach 3 degrees. Following.

在水处置上运用的多介质过滤器，罕见的有：无烟煤-石英砂-磁铁矿过滤器，活性炭-石英砂-磁铁矿过滤器，活性炭-石英砂过滤器，石英砂-陶瓷过滤器等。

Multimedia filters used in water treatment are rare: anthracite-quartz sand-magnetite filter, activated carbon-quartz sand-magnetite filter, activated carbon-quartz sand filter, quartz sand-ceramic filter and so on.

多介质过滤器的滤层设计，次要思索的要素爲：

Secondary considerations in the design of multi-media filters are as follows:

1、不同滤料具有较大的密度差，保证反洗扰动后不会发作混层景象。

1. Different filters have large density difference, which ensures that the mixed layer will not occur after backwashing disturbance.

2、依据产水用处选择滤料。

2. Selection of filter material according to the use of water production.

3、粒径要求上层滤料粒径小于下层滤料粒径，以保证上层滤料的无效性和充沛应用。

3. Particle size requires that the particle size of upper filter material is smaller than that of lower filter material, so as to ensure the invalidity and abundant application of upper filter material.

现实上，以三层滤床爲例，下层滤料粒径大，有密度小的轻质滤料组成，如无烟煤、活性炭;中层滤料粒径居中，密度居中，普通爲石英砂组成;上层滤料由粒径小，密度大的重质滤料组成，如磁铁矿。由于密度差的限制，三层介质过滤器的滤料选择根本上是固定的。下层滤料起粗滤作用，上层滤料起精滤作用，这样就充沛发扬了多介质滤床的作用，出水水质分明好于单层滤料的滤床。而关于饮用水，普通制止运用无烟煤，树脂等滤料。

In fact, taking the three-layer filter bed as an example, the lower filter material is composed of light filter material with large particle size and small density, such as anthracite and activated carbon; the middle filter material with medium particle size and density is composed of quartz sand; the upper filter material is composed of heavy filter material with small particle size and high density, such as magnetite. Due to the limitation of density difference, the choice of filter material for three-layer media filter is basically fixed. The lower filter material plays the role of coarse filtration, and the upper filter material plays the role of fine filtration. Thus, the function of multi-media filter bed is fully developed, and the quality of effluent is better than that of single-layer filter material. As for drinking water, anthracite, resin and other filters are generally prohibited.

石英砂过滤器

Quartz sand filter

石英砂过滤器是一种采用石英砂作爲滤料的过滤器。可无效去除水中的悬浮物，并对水中的胶体、铁、无机物、农药、锰、细菌、病毒等净化物有分明的去除作用。其有过滤阻力小，比外表积大，耐酸碱性强，耐氧化，PH适用范围爲2-13，抗净化性好等优点，石英砂过滤器的共同优点还在于经过优化滤料和过滤器的设计，完成了过滤器的自顺应运转，滤料对原水浓度、操作条件、预处置工艺等具有很强的自顺应性，即在过滤时滤床自动构成上疏下密形态，有利于在各种运转条件下保证出水水质，反洗时滤料充沛散开，清洗效果好。砂过滤用具有过滤速度快、过滤精度高、截污容量大等优点。普遍用于电力、电子、饮料、自来水、石油、化工、冶金、纺织、造纸、食品、游泳池、市政工程等各种工艺用水、生活用水、循环用水和废水的预处置范畴。石英砂过滤器设备构造复杂、运转可以完成自动控制、处置流量大、反冲次数少、过滤效率高、阻力小、操作维修方便等特点。

Quartz sand filter is a kind of filter which uses quartz sand as filter material. It can effectively remove suspended solids in water, and has distinct removal effects on colloids, iron, inorganic substances, pesticides, manganese, bacteria, viruses and other purifiers in water. It has the advantages of small filtration resistance, large specific surface area, strong acid and alkali resistance, oxidation resistance, PH application range of 2-13, good purification resistance, etc. The common advantage of quartz sand filter lies in the self-adaptive operation of the filter through optimizing the design of filter material and filter. The filter material has strong self-adaptability to the concentration of raw water, operating conditions and pre-treatment process, that is, when filtering. The filter bed automatically forms the upper sparse and lower dense form, which is beneficial to ensuring the quality of effluent under various operating conditions. When backwashing, the filter material is abundantly dispersed and the cleaning effect is good. Sand filter has many advantages, such as fast filtering speed, high filtering precision and large capacity of intercepting pollutants. It is widely used in the fields of power, electronics, beverage, tap water, petroleum, chemical industry, metallurgy, textile, paper-making, food, swimming pool, municipal engineering and other process water, domestic water, recycled water and wastewater pretreatment. The quartz sand filter has the characteristics of complex structure, automatic control, large disposal flow, less backwash times, high filtration efficiency, low resistance and easy operation and maintenance.

活性炭过滤器

Activated carbon filter

滤料爲活性炭，用于去除色、味、余氯和无机物，其次要作用方式是吸附，活性炭是一种人工制成的吸附剂。

The filter material is activated carbon, which is used to remove color, taste, residual chlorine and inorganic substances, followed by adsorption. Activated carbon is an artificial adsorbent.

活性碳过滤器普遍用于生活用水及食品工业、化工、电力等行业的水的预处置。由于活性炭具有兴旺的细孔构造和宏大的比外表积，因而对水中的溶解性无机物，如苯类，酚类化合物等具有很强的吸附才能，而且关于用生物法和化学法很难去除的无机净化物，如色度、异臭、外表活性剂、分解洗濯剂和染料等都有较好的去除效果。粒状活性炭对水中的Ag^ ，Cd^2 ，CrO4^2-等离子去除率达85%以上。经过活性炭滤床后，水中悬固小于0.1mg/L，COD去除率普通爲40%~50%，游离氯小于0.1mg/L。

Activated carbon filters are widely used in the pretreatment of domestic water and water in food industry, chemical industry and power industry. Activated carbon has a flourishing porous structure and a large specific surface area, so it has a strong ability to adsorb soluble inorganic substances in water, such as benzene, phenolic compounds, and other inorganic purifiers, such as chroma, odor, surfactant, decomposition detergent and dyes, which are difficult to remove by biological and chemical methods, have good removal effect. The removal rates of Ag^, Cd^2, CrO4^2-in water by granular activated carbon are more than 85%. After activated carbon filter bed, suspension in water is less than 0.1 mg/L, COD removal rate is generally 40%~50%, and free chlorine is less than 0.1 mg/L.

反冲洗工艺

Backwashing process

过滤器的反洗，次要是指过滤器在运用一定周期后，其滤料层截留和吸附一定量的杂物和污渍，这使得过滤器的出水水质下降，次要表征：过滤器的正常滤后水量变差，进水和出水管道的压力差增大，同时，单台过滤器的流量降低。 反冲洗的原理：水流逆向经过滤料层，使滤层收缩、悬浮，借助水流的剪切力和颗粒的碰撞摩擦力清洗滤料层使滤层内的污物脱离并随反洗水排出。

Backwashing of filters mainly refers to the interception and adsorption of a certain amount of impurities and stains by the filter material layer after a certain period of operation, which makes the water quality of the filters decrease. Secondary characterization: the normal filtered water flow of filters becomes worse, the pressure difference between the inlet and outlet pipelines increases, and the flow of a single filter decreases. The principle of backwashing is that water flows backward through the filter material layer to make the filter shrink and suspend. The filter material layer is cleaned by shearing force of water flow and collision friction of particles, so that the dirt in the filter layer is separated and discharged with the backwashing water.

反冲洗的必要性

Necessity of backwashing

(1)在过滤进程中，原水中的悬浮物等被滤料层截留吸附并不时地在滤料层中积聚，于是滤层孔隙逐步被污物梗塞，在滤层外表构成滤饼，过滤水头损失不时添加。当到达某一限制时，滤料需停止清洗，使滤层恢停工作功能，持续任务。

(1) In the process of filtration, suspended substances in raw water are intercepted and adsorbed by the filter material layer and accumulate in the filter material layer from time to time. As a result, the pore of the filter layer is gradually obstructed by dirt, forming filter cake on the surface of the filter layer, and the loss of the filter head is added from time to time. When reaching a certain limit, the filter material needs to stop cleaning, so that the filter layer restores its working function and continues its task.

(2)过滤时由于水头损失添加，水流对吸附在滤料外表的污物的剪切力变大，其中有些颗粒在水流的冲击下移到上层滤料中去，终会使水中的悬浮物含量不时上升，水量变差，当杂质透过滤层时，过滤器得到过滤效果。因而，到一定水平时，需求清洗滤料，以便恢复滤料层的纳污才能。

(2) The shearing force of water flow on the pollutants adsorbed on the surface of filter material increases with the increase of water head loss during filtration. Some of the particles move to the upper filter material under the impact of water flow, which will eventually cause the suspended matter content in water to rise from time to time and the water quantity to deteriorate. When impurities pass through the filter layer, the filter will get the filtering effect. Therefore, at a certain level, it is necessary to clean the filter material in order to restore the ability of the filter material layer to absorb contamination.

(3)污水中的悬浮物中含有少量无机物，临时滞留在滤层中会招致滤层中细菌微生物富集繁衍，发作厌氧糜烂景象，需活期清洗滤料。

(3) The suspended matter in sewage contains a small amount of inorganic substances, temporary residence in the filter layer will lead to the enrichment and multiplication of bacteria and microorganisms in the filter layer, and the occurrence of anaerobic erosion, which requires active cleaning of the filter material.

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In summary, all of the above-mentioned Jinan Lianzhong Heating Equipment Factory provides, want to know Shandong multi-media filter knowledge, welcome to pay attention to our website. http://www.jnlzsb.com Thank you for your support!