Quartz sand filter and air-water backwashing method thereof

Abstract

The invention relates to the field of water treatment facilities, and provides a quartz sand filter and an air-water backwashing method thereof. The quartz sand filter is successively equipped with a filter layer, a first support layer, a second support layer and a third support layer, inside thereof. A layer of air inlet pipe is arranged on an interface of the filter layer and the first support layer inside the quartz sand filter. The air inlet pipe comprises a main air inlet pipe and auxiliary air pipes connected to the main air inlet pipe, wherein the main air inlet pipe is connected with an air inlet arranged on an outer wall of the quartz sand filter; the auxiliary air pipe is equipped with air outlets; and the air inlet pipe is equipped with an intake valve. The backwashing method comprises steps of: (1) air is sent onto the filter layer through the air inlet pipe under a pressure less than 1.5KG / CM<2> and with an air input of 10-15L / S.M<2> to stir the polluted and blocked filter layer; meanwhile, water is sent from bottom at a speed of 10-15M / H, so as to realize mixed cleaning of air and water; (2) air inletting is stopped, and water is sent through a water outlet pipe in the bottom support layer of a filter cylindrical shell to carry out effective and thorough backwashing on the quartz sand layer. Small backwashing water volume and short time of the method in the invention can avoid possibilities of disordered layer and fine sand leakage of a whole arrange sand layer.

Description

technical field [0001] The invention relates to the field of water treatment devices, in particular to a quartz sand filter and a steam water backwashing method thereof. Background technique [0002] Quartz sand filter is a pretreatment equipment in the water treatment system, and there is a quartz sand layer inside it, from top to bottom: [0003] Filter layer - quartz sand: 0.4-0.6mm (grain size) 600-800mm (height) [0004] Supporting layer - quartz sand: 0.6-1.2mm (grain size) 200-400mm (height) [0005] Supporting layer - quartz sand: 1.2-2.0mm (grain size) 200mm (height) [0006] Supporting layer - quartz sand: 3.0-5.0mm (grain size) 200mm (height) [0007] The water inlet of the quartz sand filter is located at the top of the filter cylinder, above the filter layer, and the water outlet is located at the bottom of the filter cylinder, within the supporting layer. Quartz sand is used as a filter material, so that impurities such as particles, suspended solids, sludg...

AI Technical Summary

Problems solved by technology

However, during operation, the 0.4-0.6mm quartz sand filter layer is easily polluted and agglomerated by suspended solids, sludge, colloids and other impurities in the water. It needs to be backwashed and washed with a lot of water, and the cleaning time Very long, and even then it's hard to get it back to optimal filtering

[0008] In the prior art, there is also a method of combined cleaning with steam and water. The air enters from the bottom of the quartz sand filter cylinder, but it still cannot effectively clean the polluted and agglomerated quartz sand filter layer (0.4-0.6mm filter material). Agitation (loosening), and because the filter sand layer and the supporting layer are arranged from top to bottom, from fine to coarse, the agitation of the sand layer from the bottom is likely to stir the entire sand layer, resulting in 0.4- The 0.6mm quartz sand filter layer has sand particles sinking, which reduces the filtering effect, and even small sand particles leak into the back-end system, causing irreparable losses

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