In the water treatment process of multi-media filter, filtration generally refers to the process of quartz sand and anthracite filter material layer intercepting suspended impurities in water and making water clear. Quartz sand is the most common porous material for filtration. With granular filter materials, powders and various fibers. Commonly used with quartz sand, anthracite activated carbon, magnetite, garnet, porous ceramics and plastic balls and so on.

过滤器 内多介质滤料为均粒砾石、石英砂、磁铁矿、无烟煤等滤料，这些滤料根据其比重和粒径的大小在过滤器罐体内科学有序的分布，如比重小而粒径稍大的无烟煤放在滤床的更上层，比重适中和粒径小的石英砂放在滤床的中层，比重大和粒径大的砾石放在滤床的更下层。这样的配比保证了过滤器在进行反洗的时候不会产生乱层现象，从而保证了滤料的截留能力。

filter The multi-media filter media in the filter tank are high-quality homogeneous gravel, quartz sand, magnetite, anthracite and other filter media. These filter media are scientifically and orderly distributed in the filter tank according to their specific gravity and particle size. For example, anthracite with small specific gravity and slightly larger particle size is placed in the top layer of the filter bed, quartz sand with moderate specific gravity and small particle size is placed in the middle layer of the filter bed, and gravel with large specific gravity and particle size is placed in the bottom layer of the filter bed The bottom. This ratio ensures that the filter will not produce disordered layer when backwashing, so as to ensure the interception capacity of filter material.

多介质过滤器(又称机械过滤器)是以成层状的无烟煤、砂、细碎的石榴石或其他材料为床层，一个典型的多介质过滤器。

Multi media filter (also known as mechanical filter) is a typical multi-media filter with layered anthracite, sand, fine garnet or other materials as the bed.

床的由更轻和更粗品级的材料组成，而更重和更细品级的材料放在床的低部。其原理为按深度过滤--水中较大的颗粒在被去除，较小的颗粒在过滤器介质的较深处被去除。从而使水质达到粗过滤后的标准。

The top layer of the bed consists of the lightest and coarsest grade materials, while the heaviest and finest grade materials are placed in the lower part of the bed. The principle is deep filtration - the larger particles in the water are removed at the top layer, and the smaller particles are removed at the deeper part of the filter medium. So that the water quality can reach the standard after coarse filtration.

设备是压力式的，其原理是当原水自上而下通过滤料时，水中悬浮物由于吸附和机械阻流作用被滤层表面截留下来;当水流进滤层中间时，由于滤料层中的砂粒排列的更紧密，使水中微粒有更多的机会与砂粒碰撞，于是水中凝絮物、悬浮物和砂粒表面相互粘附，水中杂质截留在滤料层中，从而得到澄清的水质。经过滤后的出水悬浮物可在5毫克/升以下。

The principle of the equipment is that when the raw water passes through the filter material from top to bottom, the suspended solids in the water will be intercepted by the surface of the filter layer due to adsorption and mechanical resistance; When the water flows into the middle of the filter layer, because the sand particles in the filter layer are arranged more closely, the particles in the water have more chances to collide with the sand particles, so the flocs, suspended solids and sand particles in the water adhere to each other, and the impurities in the water are trapped in the filter layer, so as to obtain the clarified water quality. The suspended solids in the filtered effluent can be less than 5 mg / L.

多介质过滤器是由几种过滤介质组合添装，在一定的压力下使浊度较高的水通过过滤器，有效去除悬浮物杂质使水澄清的过程，常用的滤料有石英砂，无烟煤，锰砂等，主要是用于水质深度净化的预处理，可根据工艺要求填加不同的滤料。

The multi-media filter is a process of adding several filter media to make the water with high turbidity pass through the filter under a certain pressure to effectively remove the suspended solids and impurities and make the water clear. The commonly used filter media are quartz sand, anthracite, manganese sand, etc., which are mainly used for the pretreatment of water quality deep purification. Different filter media can be added according to the process requirements.