Multi-media filter packing selection

2021-07-17

Multi-media filter is a device that uses filter media to pass water with higher turbidity through a certain thickness of granular or non-granular materials under a certain pressure to effectively remove suspended impurities and clarify the water. The equipment is mainly used for water treatment to remove turbidity, softened water, pre-treatment of pure water, etc. The turbidity of the effluent can reach below 3 degrees. So how does the selection and filling of the filler of the equipment proceed?

1. Multi-media filter packing selection instructions
Common filter materials include: anthracite, ceramsite, quartz sand, activated carbon, etc. Among these types of filter materials, quartz sand has the advantages of high density, small particles, and low price; anthracite has the advantages of low density, strong pollution interception ability, etc. Larger particles are more affordable. Anthracite takes into account the retention of quartz sand and the adsorption of activated carbon. It is often used for sewage treatment and degreasing filtration. Activated carbon has the characteristics of low density, strong deodorizing and decolorizing ability, and high price. It is generally used in the filtration of drinking water. Therefore, when choosing packing for a multi-media filter, you need to understand the characteristics of each packing and your own needs, and choose the packing according to your own needs.

2. Multi-media filter filter material filling instructions
The filter layer design of the equipment generally needs to consider the particle size requirements, for example, the particle size of the lower filter material is smaller than the particle size of the upper filter material to ensure the effectiveness and full utilization of the lower filter material. In order to ensure the principle of layering after backwashing, the density of the upper layer needs to be small, and the filter material of the upper layer will sink to the lower layer after backwashing. Take a two-layer filter bed as an example. The upper layer is composed of light filter materials with large filter particles and low density, such as anthracite and activated carbon; the lower layer is generally composed of quartz sand with small particle size and high density. The formation of the upper filter material plays the role of coarse filtration, the resistance is low and the head loss is small, the lower filter material plays the role of fine filtration and has strong dirt interception ability, so that the role of the multi-media filter bed is fully played.

From this point of view, the selection of the filter material of the multi-media filter should not only be based on its own needs, but also the filling of the filter material should be based on its own needs. At the same time, when the equipment is in use, it needs to be operated by a dedicated staff to ensure that there will be no avoidable errors that affect the operation of the equipment.