Types of Self Cleaning Filters

JX Filtration December 13, 2023 Self Cleaning Filter

Self-cleaning filters are devices that directly intercept impurities in water using filter screens to remove suspended solids, particles, reduce turbidity, purify water quality, and decrease the generation of system dirt, algae, rust, etc. These precision devices, which purify water quality and protect the normal operation of other system equipment, allow water to enter the self-cleaning filter body through the water inlet. Due to intelligent design (PLC, PAC), the system can automatically recognize the degree of impurity deposition, and the drain valve signal is automatically fully opened.

Scraping Type Self-Cleaning Filter

(1) Filtration Principle: Liquid enters from the inlet, and the scraper is closely attached to the inner surface of the filter screen. The liquid flows through the scraper and flows outward from the inner surface of the filter screen, and impurities are trapped on the inner surface. The liquid flows out from the outlet. As time goes on, impurities gradually increase. When the pressure difference reaches the set value, the scraping type self-cleaning filter will start the automatic cleaning process.

(2) Cleaning Principle: The motor of the scraping type self-cleaning filter is equipped with a scraper with a corrector. The scraper performs up-and-down reciprocating motion to clean the filter screen. When the scraper moves downward, impurities are pushed to the bottom of the filter, and heavy impurities settle in the collection chamber. When the scraper of the scraping type self-cleaning filter moves upward, residual impurities are pushed to the upper end of the filter screen, and impurities are washed away by the flowing liquid, passing through the scraper and returning to the inner surface of the filter screen. When the scraper moves downward, it is scraped away. The scraping type self-cleaning filter performs several strokes for each cleaning, and after cleaning the filter surface, it restores filtering capacity. Normal filtration and flow are not interrupted during cleaning.

(3) Drainage Principle: After multiple cleaning cycles, when impurities accumulate to a certain amount, it is necessary to periodically open the drain valve of the scraping type self-cleaning filter to discharge the waste liquid in the collection chamber. If necessary, it can also be recovered.

Suction Type Self-Cleaning Filter

The water of the suction-type self-cleaning filter enters from the inlet, first passes through the coarse filter screen to filter out larger particles of impurities, and then reaches the fine filter screen. During the filtration process, the fine filter screen gradually accumulates dirt and impurities in the water, forming a layer of impurities. Due to the accumulation of impurities on the inner side of the fine filter screen, a pressure difference is formed on both sides of the fine filter screen.

When this pressure difference reaches the preset value, the self-cleaning process will start automatically: the drain valve opens, the hydraulic motor chamber of the main pipe component releases pressure, and the water is discharged. The pressure in the hydraulic motor chamber and the pressure in the suction chamber drop significantly. Due to the negative pressure, the pressure difference between the suction pipe and the cleaning chamber generates suction through the suction nozzle, creating a suction process.

At the same time, the electric motor of the filter drives the suction pipe to rotate spirally. The axial movement of the suction pipe driven by the piston of the hydraulic cylinder, the combination of axial movement and rotation completely cleans the inner surface of the filter screen. The entire cleaning process takes only tens of seconds. The drain valve is closed at the end of the cleaning. The increased water pressure will cause the piston of the hydraulic cylinder to return to its initial position, and the self-cleaning filter will prepare for the next cleaning cycle. During the cleaning process, the normal filtration of the filter is uninterrupted.

Backwash Self-Cleaning Filter

The water of the backwash self-cleaning filter enters the filter through the inlet, first passes through the coarse filter core assembly to filter out larger particles of impurities, and then reaches the fine filter screen. After the fine filter screen filters out fine particles of impurities, clean water is discharged through the outlet. During the filtration process, impurities gradually accumulate on the inner side of the fine filter screen, forming a pressure difference on both sides of the fine filter screen.

When this pressure difference reaches the preset value, the filter will start the automatic cleaning process: the drain valve opens, the hydraulic motor chamber and the hydraulic cylinder of the main pipe component release pressure, and the water is discharged. The pressure in the hydraulic motor chamber and the pressure in the suction chamber drop significantly. Due to the negative pressure, the suction nozzle generates suction through the pressure difference between the suction pipe and the cleaning chamber, creating a suction process.

JX FILTRATION is a global manufacturer, exporter, and supplier of a wide range of high-performance filtration equipment and a diverse range of high-performance filter elements, including self-cleaning filters, bag filters, cartridge filters, centrifugal solid-liquid filters, candle filter systems, basket filters, etc. The company's series of products have been recognized and praised by customers worldwide.