How To Solve The Phenomenon of Chaotic Layering of Filter Materials in Multi-media Filters？

The filling order of filter materials in multi-media filters is as follows: anthracite with low density and large particles is selected for the upper layer, followed by quartz sand with high density and small particles, and the bottom layer is a large particle support layer. The reasons for the occurrence of chaotic layer are: first, the backwash intensity is too strong, resulting in excessive backwash water volume, thus forming chaotic layer; second, the water distribution system under the multi-media filter is unevenly distributed, and the local backwash water volume is large, and a certain area has a large amount of backwash water. The amount of backwash water in some parts is small, causing chaos. It is recommended to observe the expansion height of the filter material during backwashing. If the expansion is high, it may be that the backwash water volume is too large; if the expansion height is not large, it is likely to be caused by uneven water distribution or low inlet water flow.

After the filter material becomes turbulent, the filtration effect becomes worse and the effluent pollution index is unqualified, which shortens the operation cycle of the filter element of the subsequent security filter, increases operating costs, and accelerates reverse osmosis pollution. The solution to the phenomenon of filter material chaos is: take out all the filter material from the filter and re-screen it with a sieve with the same mesh size as the filter material. This method is time-consuming and labor-intensive and cannot fully achieve the re-separation effect. Generally, Not adopted. Replace the new filter material. In order to prevent the filter material from being disrupted again, the operating procedures must be strictly followed during the backwashing process, and the backwash water volume must be controlled. The backwash water volume should be 2.5 to 4 times the normal operating water output. In addition, the backwash water volume must be 2.5 to 4 times the normal operating water output. The wash water inlet valve should be opened slowly to avoid instantaneous large flow backwash; if the lower water collection system of the multi-media filter adopts a dome-shaped plate device, it should be changed to a partition water cap device with more uniform water distribution (the water cap is the most It is best to use a double-speed filter cap) to prevent layer chaos caused by large amounts of local backwash water.