1、 The application of disc filters
In various working conditions of production and life, we often use filtration systems. The commonly used filtration systems mainly include pressure filters, mesh filters, membrane filters, filter media (packing media) filters, filter cartridge filters, bag filters, etc. according to different usage requirements. These filtering devices are applied to different working conditions and have their own advantages.
In some applications with high flow and fast filtration speed, disc filters can be used. It can be widely used in industrial and commercial fields, such as HVAC systems in food, textile, metallurgy, plastics, medicine, building materials, papermaking, industrial and commercial buildings.

2、 Working principle of complete equipment
1. Working status:
The sewage flows into the filter through the main inlet pipe, passes through the backwash valve (in this state, the backwash valve allows water to pass through the filter while closing the drainage port), and flows towards each filter disc group of the filter. In the filtration process, the sewage is intercepted in each filter disc group (in the space formed by the curved edges on the disc). The filtered clean water flows out of the internal channels of each filter disc group and enters the main outlet, and is directly supplied to the water section of the system from the outlet.
2. Recoil state
The accumulation of dirt in the filter disk group causes a pressure difference between the inlet and outlet of each filter disk group. When the pressure difference (Δ P) of the filter reaches a pre-set value, the system automatically starts a backwash process. The first backwash valve on the system opens first, triggering several actions simultaneously: the flushing valve closes the outlet of the filter unit and opens the backwash discharge outlet. The filtered clean water from other filtration units in the system enters the backwashing state of the filtration unit through the main outlet, flows into the interior of the disc group through the outlet, and flows out from the outer edge of the disc group together with the dirt to the sewage outlet.
In this way, the water flow removes all dirt from the entire disc assembly.
The backwash cycle is controlled by the pressure difference data on the controller, and the flushing valve is opened and closed through the signal of the time controller. The controller controls the flushing process so that only one filter unit is in backwash state at the same time, while other filter units continue to provide clean water to the system. The flushing process will automatically stop after a certain period of time, and the duration can be pre-set on the controller.

3、 Important control components
1. Differential pressure gauge
For filters, the control method that indicates system blockage and requires backwashing is the differential pressure control method using a differential pressure sensor.
The differential pressure sensor directly reflects the blockage of the equipment, and uses differential pressure as the main control method to keep the filtration system in an effective working mode.
2. Backwash three-way valve
The three-way diaphragm valve, as a backwash valve, is mainly used in various filters. It is generally installed at the inlet of the filter, such as sand filters, activated carbon filters, sponge iron filter deaerators, etc. This valve can achieve automatic control and change the direction of water flow through hydraulic control signals.

4、 Performance characteristics of disc filtration system
1. Efficient and precise filtration:
The special structure filter disc filtration technology has precise and sensitive performance, ensuring that only particles with a diameter smaller than the required size can enter the system, making it an effective filtration system; There are various specifications such as 5 μ, 10 μ, 20 μ, 55 μ, 100 μ, 130 μ, 200 μ, etc. Users can choose different precision filter discs according to their water requirements. The system traffic can be flexibly adjusted as needed.
2. Standardized modularization, saving space:
The system is based on standard disc filter units, designed modularly, allowing users to choose according to their needs, flexible and adaptable, with strong interchangeability. The system is compact, occupies a small area, and can flexibly utilize corner space for installation. For example, equipment with a processing capacity of about 300 m3/h occupies only about 6m2 (for general water quality, with a filtration level of 100 μ).
3. Fully automatic operation, continuous water discharge:
The backwashing process alternates between each unit in the filter combination, automatically switching between working and backwashing states to ensure continuous water discharge; Backwashing consumes less water, accounting for only 0.5% of the water output; If combined with air assisted backwashing, the self consumption of water can be reduced to less than 0.2%. High speed and thorough backwashing can be completed in just a few seconds
4. Long lifespan:
The new plastic filter element is sturdy, wear-resistant, corrosion-resistant, and less prone to scaling. After years of industrial practical verification, it has been used for 6-10 years without wear or aging, and the filtration and backwashing effects will not deteriorate due to usage time.
5. High quality, low maintenance:
The products meet the corresponding quality standards, and all products undergo simulated working condition testing and trial operation before leaving the factory, without the need for special tools and with few components; Easy to use, only requires regular inspections, and almost no daily maintenance.

5、 Equipment selection
1. The selection of disc filters mainly involves determining the type and number of filter heads that make up the filtration system.
2. This depends on three factors: raw water quality, filtration level, and required water flow rate. (Refer to "Application Reference for Disc Filter System")
1)Raw water qualityDivided into four categories: excellent, average, poor, and very poor
A.Excellent water qualityUnpolluted urban tap water and well water extracted from stable aquifers;
B.General water qualityCirculating cooling water, tap water with poor water quality, surface water treated by sedimentation, and drainage treated by effective sedimentation and complete biological treatment;
C.Poor water qualityGroundwater extracted from aquifers with poor water quality, wastewater that has undergone effective sedimentation but has not undergone or has undergone minimal biological treatment, and surface water with abundant microbial growth;
D.Poor water qualityWell water with high or dirty iron content, surface water affected by floods without sedimentation, river water or other surface water with high suspended solids content, untreated drainage.
(To ensure effectiveness, this type of water quality needs to be pre treated and can be equipped with an auxiliary sand remover. The suspended solids content in the influent can reach 1400 g/L. When the water quality is complex, such as high iron and manganese content, it needs to be pre treated with aeration or flocculation.)