Multi media filter can use a single medium, or choose different media according to their own needs. The multi-media filter can also be divided into single multi-media filter and multi-media filter. Single media filter can also be called shallow media filter, its main filter media are generally quartz sand, granite and volcanic gravel.

多层介质过滤器可称为深 层次介质过滤器，它的过滤介质是由一种以上的过滤介质组成，一般滤料有石英砂，活性炭，无烟煤，锰砂以及其他的接触性介质。

Multilayer media filter can be called deep media filter, its filter media is composed of more than one kind of filter media, the general filter media are quartz sand, activated carbon, anthracite, manganese sand and other contact media.

在过滤刚开始时，需要过滤的水会通过进水口进入介质层，这时大部分的污染物会被拦截在介质的上表面，少量比较细小的污物以及其他的浮动有机物会被截留在介质层的内部，使系统的出水水质可以达到要求，保证系统在生产时不会受到污染物的干扰，可以良好的运行。

At the beginning of filtration, the water to be filtered will enter the medium layer through the water inlet. At this time, most of the pollutants will be intercepted on the upper surface of the medium, and a small amount of relatively small pollutants and other floating organic matter will be intercepted in the medium layer, so that the effluent quality of the system can meet the requirements, and the system will not be disturbed by pollutants during production, It can run well.

当水质中的杂质和各种悬浮物到达一定量的时候，该过滤系统可以通过压差控制装置实时的检测进出口的压差，当压差达到设定值时，电控盒会给控制系统中的三通水力控制阀发送信号，三通水力控制阀会通过水路自动控制它所对应的过滤单元三通阀门.

When the impurities and various suspended solids in the water reach a certain amount, the filter system can detect the pressure difference at the inlet and outlet in real time through the pressure difference control device. When the pressure difference reaches the set value, the electric control box will send a signal to the three-way hydraulic control valve in the control system, and the three-way hydraulic control valve will automatically control the corresponding three-way valve of the filter unit through the waterway

让它可以关闭进口通道的同时打开排污通道，这时会由于排污通道的压力会比较小，其他的过滤单元的水会在水压力的作用下由通过该过滤单元的排污口进入排污管道，完成排污过程。

It can close the inlet channel and open the blowdown channel at the same time. At this time, because the pressure of the blowdown channel will be relatively small, the water of other filtering units will enter the blowdown pipeline through the blowdown outlet of the filtering unit under the action of water pressure, and complete the blowdown process.