Precision filter

► Operating Principle

　　Precision filters mostly use filter cloth, filter mesh, filter plates, sintered filter tubes, wound filter cartridges, melt-blown filter cartridges, etc., as filter elements. Under pressure, the raw water passes through the filter material, and the filter residue remains on the pipe wall, while the filtered water permeates the filter material and flows out, thus achieving the purpose of filtration.

　　Precision filters can remove suspended solids, certain colloidal substances, and fine particles from water.

► Performance Characteristics

　　1. High filtration accuracy, small size, large filtration area;
　　2. Low filtration resistance, high energy, strong interception capacity, long service life;
　　3. High cleanliness of filter element material, no pollution to the filtration medium;
　　4. Resistant to acids, alkalis, and other chemical reagents;
　　5. High strength, high temperature resistance, filter element is not easily deformed;
　　6. Low price, low operating cost, easy to clean, filter element can be replaced, small footprint, etc.
　　Precision filters are widely used in the pretreatment and post-treatment systems of water in the electronics, petroleum, chemical, pharmaceutical, and food industries. They are generally installed before electrodialysis and reverse osmosis and after ion exchange beds.

► Equipment Composition

　　The shell material of the precision filter includes: organic glass, stainless steel, fiberglass reinforced plastic, and anticorrosion carbon steel. It is generally made into a cylindrical container, filled with filter material, and combined with operating pipes and valves. The filter element accuracy is 0.2, 0.45, 1, 3, 5, 10, 20, 30, 50, 75, 100μm, etc. Different accuracy filter elements are selected to achieve different water quality and water volume. Specific specifications, materials, filter materials, and accuracy depend on water requirements and actual conditions. Specifications are Øl50----1500mm, and water production ranges from lt/h²—50t/h².

► Operation and Backwashing of Precision Filters

　　1. Operation: At the beginning of operation, open the inlet valve. Water enters the filter from the bottom of the precision filter. After the container is filled with water, a section of water is discharged through the bottom drain valve (first rinse the container) before closing the bottom drain valve and opening the outlet valve. The water entering from the bottom of the precision filter is filtered through the filter material and supplied to the next level through the outlet valve.
　　2. Backwashing: After a certain period of operation, when the amount of intercepted material in the filter material increases and the water output decreases or the pressure difference is greater than or equal to 0.05MPa, backwashing should be performed: Close the inlet valve and outlet valve, open the backwash valve and bottom drain valve, and backwash the filter material and discharge the pollutants until the backwash water is clear.

► Precautions

　　1. The concentration of suspended solids in the inlet water should be less than 2ppm. Surface water should be clarified, coagulated, and filtered before using precision filtration.

　　2. Before use, rinse the surfactant and soda ash impurities in the filter with clean water.

　　3. The working pressure difference should not be greater than 0.05MPa.