HydroPro-ZZS Filter

HydroPro-ZZS Self-Cleaning Filter For Paper Mill Water Treatment
HydroPro-ZZS Self-Cleaning Filter For Paper Mill Water Treatment

HydroPro-ZZS self-cleaning filter is a filtration equipment for treating wastewater from paper mills. Its key component is the scraper mechanism. However, the scraper mechanisms currently on the market are often difficult to clean thoroughly. Given this defect of the scraper mechanism, a new scraper mechanism was developed based on the analysis of the structures of many scraper mechanisms at home and abroad. In the process of treating paper mill wastewater, ensure that the scraper mechanism is always in contact with the filter screen. This can effectively and thoroughly remove debris deposited on the filter.

HydroPro-ZZS self-cleaning filter has the advantages of efficient self-cleaning and low-pressure loss. Among them, brush-type (scraper-type) self-cleaning filters have obvious advantages when filtering media containing viscosity is required. Therefore, it is most suitable for use in environments with harsh working conditions in industries such as metallurgy, chemical industry, and papermaking.

The HydroPro-ZZS self-cleaning filter uses a scraper to remove sticky particles. Therefore, the scraper mechanism is a key component of the self-cleaning filter, and its cleaning effect mainly depends on the structure of the scraper. The scraper self-cleaning filters currently on the market are difficult to ensure complete local cleaning. This article will introduce in detail the working principle of the HydroPro-ZZS self-cleaning filter, the structure, and the design method of the scraper mechanism.

Structure and working principle of HydroPro-ZZS self-cleaning filter

  • After the medium enters the HydroPro-ZZS self-cleaning filter, impurity particles smaller than the mesh size pass through the filter.
  • Then it flows out from the filter outlet together with the filtered media.
  • Impurity particles are larger than the mesh size. Part of it is directly deposited at the bottom of the filter barrel under the action of gravity and hydrocyclone. The other part sticks to the filter.
  • Impurities reach a certain thickness. The pressure difference between the inside and outside of the filter increases, and the pressure drop loss increases.
  • When the pressure drop loss exceeds the loss required by the filter system process. The differential pressure sensor sends a signal to the control box to start the motor. The scraper starts running to remove debris on the filter.
  • Cleaning process. The scraper is always in contact with the filter screen under the combined action of centrifugal force and spring force.
  • Impurities are removed under the action of tangential force between the scraper and the filter screen. At the same time, it prevents impurities from being squeezed onto the filter screen under the action of normal force.
  • Particles are also deposited at the bottom of the filter cartridge under the action of gravity and cyclones.
  • After the particles at the bottom of the cylinder accumulate to a certain extent, the control box opens the drain valve at the bottom of the filter to remove the particles.

Design scraper

It is necessary to ensure that there is no gap between the scraper and the filter during the working process and that the brush and filter are in contact under the action of centrifugal force. A taper pin is used to define the radial position of the brush. According to the manufacturing level of the industry, the cylindricity error of the filter should be less than 0.0008D (D is the diameter of the filter) under economical processing accuracy.

The spring is in a compressed state so that the normal pressure between the scraper and the filter screen is about 10N. Ensure that the brush and filter are in contact. The scraper is affected by the combined action of centrifugal force, the force of the spring on the scraper, and the force of the filter on the scraper. The centrifugal force is a harmful force for the removal of impurities. To reduce this harmful centrifugal force, the rotation speed of the scraper must be strictly limited.

When designing, other structures and dimensions of the scraper device are mainly considered from the perspective of reducing assembly and processing difficulties and reducing manufacturing costs. For example, to ensure the flexibility of its operation, the support mechanism uses water-lubricated bearings made of polytetrafluoroethylene. The scraper device and the reducer shaft are connected by a universal coupling to compensate for the coaxiality requirements between related assembly and manufacturing parts.


The scraper mechanism of the HydroPro-ZZS self-cleaning filter is an adaptive scraper mechanism. Can automatically adapt to changes in filter structure shape. The slide rail mechanism and spring element are used to enable the scraper to move flexibly in the radial direction. Ensure that the scraper and filter screen are always in a tight fit during the working process of the filter. Effectively ensures the cleaning effect and completely removes debris adhering to the inner surface of the filter. Keep the filter from getting clogged and reduce pressure damage.

The scraper has a fixed position along the axial direction and is evenly distributed in the axial direction. It only moves in a circular motion during operation. Ensure the reliability of scraper operation and uniform removal of debris at various locations on the filter to reduce pressure loss.

After a large number of terminal tests, it has been proved that the scraper mechanism has a reasonable structure and reliable operation. It can completely remove impurities on the filter, especially when the sewage from paper mills contains sticky impurities. More adaptable than existing scraper filters on the market. The research and development of this scraper mechanism helps improve the filtration efficiency of paper mill wastewater.