The filtration mechanism of the automatic backwashing disc filter lies in the combination of surface filtration and deep filtration achieved by using compacted plastic layers. The core technology is the lamination body, which is composed of polypropylene lamination bodies with grooves in different directions on two sides. When two adjacent lamination bodies overlap, multiple intersection points are formed at the edges of the grooves on the adjacent sides. These intersection points constitute multiple voids and irregular channels. When these channels are filtered from the outside to the inside, they will cause turbulence in the water, ultimately blocking impurities in the water at each intersection. When the stacked bodies are overlapped and installed on the frame of the filter element, under the pressure of the spring and water, the outer side will loosen, forming a filter unit with the inner side tightened. Now, let's take a detailed look at the working principle and structure of the automatic backwashing laminated filter together!

1, the depth and number of the laminated body slots determine the filtration accuracy of the filtration unit.
Work status

During the filtration process, the automatic backwashing disc filter is tightly squeezed by the spring force and water pressure. When water containing impurities passes through, large particles and coarse fibers are directly blocked - this is called surface filtration. Small particles and fibers enter the holes of the grooves and the interior of the stack. Then, as they gradually shrink along the gap, the fine particles and fibers are cut off in the middle of their respective channels. It is called so-called deep filtering.

Backwash status

Backwashing automatically starts within a preset time. The backwashing valve changes the direction of water flow within the filter unit. The spring of the filter element is pushed upward by water pressure, and all the small gaps between the layers are released. The nozzle located in the center of the filter core sprays water along the tangential line, causing the laminated body to rotate. Through the cleaning effect of the water flow and the high-speed centrifugal force of the laminated body, the solid substances enclosed in the laminated body are washed away. Therefore, a good cleaning effect can be achieved with less water. Afterwards, return the backwash valve to the filtration position and use the spring force on the filter element to press the laminated thin sheet again to bring it back to the filtration state.

2. Application in the Automatic Backwashing Disc Filter

The basic filter element of the automatic backwashing disc filter is composed of polypropylene plastic plates with grooves. The edges of the grooves on adjacent plates form multiple layers of filtration precision, capturing solid substances in water, with a filtration precision of 20-200m

The operation and backwashing of this filter are fully automatically controlled. It is simple to operate and manage, and requires little maintenance. There is no need to replace the filter element for several years. It is an advanced water treatment unit system. It is widely applied in the treatment of circulating water and wastewater in industries such as metallurgy, power, chemical engineering, and papermaking, as well as in municipal and agricultural irrigation water, river water purification, pretreatment and protection of ultrafiltration membranes/reverse osmosis membranes, and in the fields of sewage treatment and wastewater recycling. It is also widely used in high-salt water and high-turbidity water fields

3. Features of the automatic backwashing disc filter

(1) Filtration

Filtration technology allows only particles smaller than the required size to enter the system, making it an effective filtration system. There are various types such as standard precision, 20m, 50m, 100m, 150m, 200m, etc. Users can choose filter discs of different precision according to the requirements of water, and the system flow can be flexibly adjusted as needed.

(2) Through standard modularization, land is saved:

The system is based on standard disc-type filter units. The optical drive technicians adopt a modular design, allowing users to make choices as needed. It is flexible, variable and highly compatible. The system is compact and occupies a small area. It can be installed by making full use of corner space. For example, a device with a water treatment capacity of about 300 m ³ /h takes up approximately 6 square meters (for general water quality and filtration grade 100).

(3) Fully automatic operation and continuous water discharge

Among the various units in the filter assembly, the backwashing process can be alternately carried out, automatically switching the action and backwashing states to ensure a continuous supply of water. The backwash water volume is small, accounting for only 0.5% of the total water output. If combined with air-assisted backwashing, water consumption can be reduced to less than 0.2%. High-speed backwashing only takes a few dozen seconds.

The above is a detailed analysis of the working principle and structure of the automatic backwashing disc filter. If you need to know more, please feel free to contact us at any time!