The multi-column automatic backwashing disc filter is an advanced and easy-to-operate automatic filtration device, consisting of a housing, filter element, backwashing rotating mechanism, differential pressure controller and electrical control part.

1. Working principle of automatic backwash stack filter
The multi-column automatic backwashing disc filter adopts high-strength wedge-shaped wire mesh filter elements and automatically cleans the filter elements through pressure difference control and timing control. When impurities accumulate on the inner surface of the filter element and the pressure difference between the inlet and outlet increases to the set value, or when the timer reaches the preset time, the electrical control box sends a signal to drive the backwashing mechanism.

When the backwash suction cup inlet aligns with the filter element inlet, the drain valve opens. At this point, the system depresses and drains water, creating a negative pressure zone inside the suction cup and filter element where the relative pressure is lower than the water pressure outside the filter element (the backwash pressure difference is controlled at 3 to 4 times the filtration pressure difference).

A portion of the clean circulating water is forced to flow from the outside to the inside of the filter element. The impurity particles adsorbed on the inner wall of the filter element enter the tray with the water flow and are discharged through the drain valve.

2. Functions of the automatic backwashing disc filter product

Self-cleaning function: It uses its own filtered clean water to self-clean the filter screen, eliminating the need to remove the filter screen for cleaning or configure other cleaning systems.

Continuous water supply function: Multiple filter screens are installed in the water tank, which can work simultaneously. During backwashing, each filter screen is cleaned one by one while the others remain in operation, ensuring continuous water supply.

Automatic backwashing function: The pressure difference between the clear water area and the turbid water area is monitored through the differential pressure controller. When the pressure difference reaches the set value, the pressure difference controller outputs a signal, and the electrical control cabinet controls the opening and closing of the backwashing mechanism to achieve automatic backwashing.

3. Application of Automatic Backwashing Disc Filter in Water Treatment of Steel Plants

The steel industry is an important sector in the national economy and a significant indicator of national strength and the level of industrial development. Wastewater from the steel industry mainly comes from water used in the production process, cooling water for equipment and products, flue gas washing and site flushing, etc. However, 70% of the wastewater still comes from cooling water. In the "13th Five-Year Plan", it is required that the water consumption per 10,000 yuan of GDP and per 10,000 yuan of industrial added value be reduced by about 30% respectively across the country. The automatic backwashing disc filter is particularly important for vigorously promoting water-saving technologies in the country's pillar industries and the steel industry, which is also a major water consumer.

The automatic backwashing disc filter is used to filter and intercept particulate impurities in low-viscosity liquids. Its excellent structural design and automatic cleaning function provide users with stable and reliable operation performance, while significantly reducing operation and maintenance costs. Energy conservation, intelligent design, and full-process automation.

The automatic backwashing disc filter is controlled by an automatic program, featuring automatic filtration, automatic differential pressure identification, automatic backwashing and automatic sewage discharge, with low operating costs. Continuous operation, cleaning each filter element one by one, uninterrupted filtration, filtration accuracy covering 10 to 3000 microns; High efficiency, low energy consumption, large effective filtration area, low backwashing frequency, small sewage discharge volume, and small system resistance loss. The backwashing effect is excellent. The unique filter screen structure design and cleaning control method ensure high backwashing intensity and thorough cleaning.