What are precision filters in water treatment?

Author of the article:Hongjie Water

Security filter, also known as precision filter, is a type of filter widely used in the water treatment industry. Its shell is usually made of stainless steel material, with a single or multiple built-in filter elements. Under pressure, the original liquid passes through the filter material, and the filter residue remains on the pipe wall. The filtrate flows out through the filter material, achieving the purpose of filtration. Due to different filter materials, the filter aperture is also different, with a filter aperture generally ranging from 0.5 to 120 μ M range. There are many types of filter elements for equipment, such as foldable filter elements, wire wound filter elements, high flow filter elements, activated carbon filter elements, etc. 

Reason for flattening of the filter element of the security filter

Security filters are usually installed in front of pressure vessels to remove particles with a turbidity of more than 1 degree, ensuring that the inlet water meets the inlet water requirements of subsequent equipment. However, after a certain period of use, the filter element may experience flattening, which is mainly caused by:

1. The filter element has been used for a long time and has not been replaced in a timely manner

Without timely cleaning and replacement, the resistance of the raw water passing through the filter element increased. During the operation of the high-pressure pump, a vacuum state appeared in the security filter, causing the filter element to be flattened.

Precision filters are usually replaced with a pressure difference of 0.1-0.15mpa at the inlet and outlet, and are usually replaced within 3-4 months.

2. Insufficient support force of filter element framework

The skeleton has insufficient support and poor compression resistance. If the pressure increases slightly, the filter element will shrink.

3. The filter element was not selected properly, and the required filtration accuracy is not appropriate

The selection of filtration accuracy is not appropriate, and not all systems are suitable for filter elements with high filtration accuracy. In the case of poor water quality, selecting a filter element with a high pore size or a pressure exceeding its allowable high working pressure can also cause the filter element to suck flat.

4. Inappropriate inlet pressure

The fluctuating inlet pressure can also cause the filter element to become flat.

In summary, it causes the filter element to become flat and seriously affects the water purification effect. When selecting the filter element, it is necessary to comprehensively consider the operating conditions of the filter element, select the appropriate filter element model and accuracy, and replace it in a timely manner to ensure the accuracy of the effluent and the service life of the subsequent membrane components.