Quartz sand washing agent: The reason for compression is the colloidal substance accumulated in the gap between the surface of the quartz sand filter material and the surface of the filter material, which changes the flow characteristics of the filter material. During backwashing, these colloidal substances are compressed by the backwash water and easily adhere to the screen gap. The pressure of the backwash water increases (compression) and the flow rate decreases.

Quartz sand washing agent: Therefore, the presence of polymers in the sewage is a direct factor of the pressure during the backwashing of the filter tank. Reasons for running The phenomenon of running is manifested in two aspects: one is running from the upper water collection pipe during backwashing, and the other is running from the lower water distribution pipe during filtering.

Quartz sand washing agent: Normal backwashing is the first expansion of the quartz sand filter material under the action of the backwashing water. The expansion rate is determined by the backwash strength. Generally, 20%-50% is suitable for the quartz sand filter material in the water flow and Vibration, collision, and friction are generated under the dual action of gravity to form a hydraulic level. Dirt will be discharged from the upper catchment and catchment along with the water flow. Each cleaning restores the pollution ability of the quartz sand filter material to a certain degree. The end of the backwash At this time, the filter material particles forming the hydraulic grade return to the support layer in order from large to small.

Quartz sand washing agent: Therefore, even if it is a filter tank with a smooth orifice tube-perforated tube structure, the phenomenon of material running from the upper water collecting pipe during backwashing and from the lower water distribution pipe during filtering will not occur.