Cleanable security filter and its application

Abstract

The invention relates to a security filter that can realize online automatic backwashing and its application. The invention solves the technical problems that currently used filter elements in industry have low filter precision, are easy to cause deep pollution, and cannot achieve long-term use through automatic cleaning. The security filter provided in the invention can mainly be used for a double-membrane system in the field of wastewater treatment by a membrane method, such as the security filtering measures in ultrafiltration and reverse osmosis systems, and also can be applied to circulating water replenishing and other water treatment processes with high requirements for filter precision and effluent water quality. The security filter can be used as an effective pretreatment filter means to reduce the influence of particles in water or water quality change caused by inflow water impact on stable running of follow-up processes, so that the effluent water quality can be improved to meet following water use requirements.

Description

technical field [0001] The invention relates to a security filter capable of realizing on-line automatic backwashing and an application system thereof, belonging to the technical field of membrane wastewater treatment and reuse. Background technique [0002] In recent years, with the increasing shortage of fresh water resources and the strengthening of environmental protection law enforcement, technologies related to water saving and emission reduction have been further promoted and applied in practical industrial applications. Among them, the advanced sewage reuse technology - membrane separation Technology has developed rapidly under the existing technical conditions and has been applied to many fields. In a sense, membrane separation technology has become one of the technical foundations for solving current energy, resource and environmental problems and achieving sustainable development. In my country, with the introduction of membrane technology and the deepening of re...

AI Technical Summary

Problems solved by technology

With the increase of surface pollutants, the flux of the filter element will drop significantly, and the filter element in the filter cannot achieve surface filtration due to the defects of the manufacturing technology itself, which will easily lead to deep pollution

When the flux drops to a certain level, the reaction to the safety filter is that the operating pressure increases and the quality of the effluent water deteriorates. At this time, the filter element must be replaced, which increases the operation and maintenance costs.

[0005] At present, the filter elements used in industrial membrane devices have the following disadvantages: (1) The defect in the preparation process of the filter element itself makes the pore size of the filter element too large (generally about 5 μm), and the pore size distribution is uneven, resulting in low filtration accuracy of the filter element; (2) due to the The characteristics of the manufacturing process determine that the filter element cannot achieve surface filtration and is prone to deep pollution; (3) The service life of the existing industrial filter element is short. With the fluctuation of the water quality, it usually ranges from 2 weeks to 1 month and cannot be used for a long time. Frequent replacement of filter elements leads to a substantial increase in operating costs and labor costs

[0006] In view of the problems existing in the actual application of the current security filter element, such as the filter element is easy to form deep pollution, the filtration accuracy is not high, and the operation process is affected by the water quality and fluctuates greatly. At present, there are security filters that use compressed air for backwashing. , but the use of compressed air for backwashing requires high pressure of compressed air on the one hand, the pressure is too high, it is easy to damage the filter element, and the pressure is too small to achieve the purpose of backwashing. In addition, practice has proved that the effect of using compressed air for backwashing No, it is difficult for the air to completely blow away the impurities adhered to the filter element

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