During operation, the water to be filtered enters through the inlet, flows through the filter screen, and exits through the outlet into the user's process piping for circulation; particulate impurities within the water are retained inside the filter screen. As this cycle continues, the accumulation of retained particles increases, causing the filtration rate to slow down. Meanwhile, the unfiltered water continues to flow in steadily, and the effective pore size of the filter screen gradually diminishes. Consequently, a pressure differential develops between the inlet and the outlet. When this pressure differential reaches a preset threshold, a differential pressure transmitter sends an electrical signal to the controller. The control system then activates a drive motor, which-via a transmission assembly-rotates a central shaft. Simultaneously, the drain valve opens, allowing the accumulated impurities to be discharged. Once the filter screen has been thoroughly cleaned and the pressure differential drops to a minimum value, the system reverts to its initial filtration state and resumes normal operation.
The filter consists of several key components: a housing, multiple filter elements, a backwashing mechanism, and a differential pressure controller. A horizontal baffle plate within the housing divides its internal cavity into upper and lower chambers. The upper chamber houses the multiple filter elements-an arrangement that maximizes the utilization of filtration space and significantly reduces the overall physical footprint of the filter. The lower chamber accommodates the backwashing suction nozzle. During operation, the unfiltered fluid enters the lower chamber of the filter through the inlet, then flows through perforations in the baffle plate into the interior cavities of the filter elements. Impurities larger than the gaps in the filter elements are retained, while the clean fluid passes through these gaps into the upper chamber and is finally discharged through the outlet. The filter utilizes high-strength wedge-wire screens and employs a dual-mode automatic cleaning mechanism-triggered by either pressure differential control or a preset timer-to clean the filter elements. When the accumulation of impurities on the surface of the filter elements causes the pressure differential between the inlet and outlet to rise to the preset threshold, or when the timer reaches its preset duration, the electric control unit issues a signal to activate the backwashing mechanism. As the backwashing suction nozzle aligns directly with the inlet of a specific filter element, the drain valve opens. At this moment, the system depressurizes and drains water, creating a localized negative pressure zone (lower relative pressure) inside the filter element compared to the water pressure outside it.
This pressure differential forces a portion of the clean circulating water to flow inward from the exterior of the filter element. Consequently, the impurity particles adhering to the inner wall of the filter element are swept along by this reverse flow into the suction nozzle and subsequently discharged through the drain valve. The specially designed filter screen geometry generates a powerful jetting effect within the filter element, ensuring that any remaining impurities are thoroughly flushed away from the smooth inner surface. When the pressure differential between the filter's inlet and outlet returns to normal-or when the timer's preset duration elapses-the entire process concludes. Throughout this operation, the flow of material remains uninterrupted, and water consumption for backwashing is minimal, thereby achieving fully continuous and automated production.
This filter is widely utilized across various sectors, including metallurgy, chemical engineering, petroleum, papermaking, pharmaceuticals, food processing, mining, electric power, and municipal water supply. Its applications encompass the filtration of industrial wastewater and circulating water, the regeneration of emulsions, the treatment and filtration of waste oil, as well as specialized systems within the metallurgical industry-such as continuous casting water systems, blast furnace water systems, and high-pressure water descaling systems for hot rolling. It stands as an advanced, highly efficient, and user-friendly fully automated filtration device.