The main factors to be considered in the design of multi-media filter 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生混层现象。

1. Different filter media have large density difference, which ensures that there will be no mixed layer after backwashing disturbance.

2、根据产水用途选择滤料。

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

3、粒径要求下层滤料粒径小于上层滤料粒径，以保证下层滤料的有效性和充分利用。

3. Particle size requires that the particle size of the lower filter material is smaller than that of the upper filter material, so as to ensure the effectiveness and full utilization of the lower filter material.

事实上，以三层滤床为例，上层滤料粒径大，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，一般为石英砂组成；下层滤料由粒径小，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基本上是固定的。上层滤料起粗滤作用，下层滤料起精滤作用，这样就充分发挥了多介质滤床的作用，出水水质明显好于单层滤料的滤床。而对于饮用水，一般禁止使用无烟煤，树脂等滤料。

In fact, taking the three-layer filter bed as an example, the upper 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 medium density is generally composed of quartz sand; the lower 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 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 quality of effluent is obviously better than that of single-layer filter material. For drinking water, anthracite, resin and other filters are generally prohibited.

本文由山东多介质过滤器厂家提供技术支持，更多的详细精彩内容请点击我们的网站：http://www.jnlzsb.com，我们将会全心全意为您提供满意的服务。

This article is supported by Shandong Multimedia Filter Manufacturer. For more details, please click on our official website: http://www.jnlzsb.com. We will provide you with satisfactory service wholeheartedly.