Water treatment system with bidirectional cleaning function

Abstract

The invention discloses a water treatment system with bidirectional cleaning function, and aims to provide a water treatment system capable of realizing bidirectional alternate cleaning. The upper water outlet of a double-end water outlet external-pressing membrane assembly is connected with an upper filtrate collecting conduit, while the lower water outlet is connected with a lower filtrate collecting conduit; the upper filtrate collecting conduit is connected with a first control valve and a second control valve; the lower filtrate collecting conduit is connected with a third control valve and a fourth control valve; the first control valve is connected in parallel with the third control valve and then is connected with a fifth control valve, a water pump and a seventh control valve in turn; one end of an eighth control valve is connected with a second connector of the water pump, while the other end is connected in parallel with the fifth control valve; one end of a sixth control valve is connected with a first connector of the water pump, while the other end is connected in parallel with the seventh control valve; and the second control valve is connected in parallel with the fourth control valve and then is connected with a residual cleaning solution outlet. The system can realize bidirectional alternate cleaning, improve the flushing effect on pollutants in a membrane cavity, and ensure the membrane cleaning efficiency and reflux recovery rate.

Description

technical field [0001] The invention relates to the technical field of water treatment, and more specifically relates to a water treatment system with bidirectional cleaning function which utilizes hollow fiber membranes for water treatment. Background technique [0002] Hollow fiber membrane modules are widely used in the field of water treatment due to their high packing density, self-supporting, simple structure, low cost, and backwashing. Hollow fiber membrane modules can be used in many fields such as ultrapure water preparation, drinking water purification, sewage treatment, and seawater desalination. According to the structural characteristics of the hollow fiber membrane module, it can include two forms of hollow fiber single-end water outlet (that is, one end of the membrane fiber is closed, and one end is used as a collection channel for the filtrate) and double-end water outlet (that is, both ends are used as a collection channel for the filtrate) . Due to the f...

AI Technical Summary

Problems solved by technology

Since the flow directions at both ends of the double-ended water outlet membrane module are opposite during backwashing, the particles entrained in the backwash solution cannot pass through the membrane surface and cannot be discharged from the membrane cavity, and larger particles will stay in the membrane cavity to block the flow. However, substances with slightly smaller particles will adhere to the inner surface or block the membrane pores, forming membrane cavity pollution

Since most of the hollow fiber membrane materials currently used are asymmetric membranes, and the effective layer of the membrane is mostly on the outer surface of the membrane, various membrane cleaning methods will pollute the inner cavity of the membrane with this "small outside and large inside" membrane pore distribution form. hard to recover

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