When the filter is working, the water to be filtered enters through the inlet, flows through the filter screen, and exits through the outlet into the user's required pipeline for process circulation. Particulate impurities in the water are trapped inside the filter screen. This continuous circulation results in more and more particles being trapped, slowing down the filtration speed, while wastewater continues to enter, causing the filter pores to become smaller. This creates a pressure difference between the inlet and outlet. When the pressure difference reaches a set value, the differential pressure transmitter sends an electrical signal to the controller. The control system starts the drive motor, which drives the shaft to rotate via the transmission assembly. Simultaneously, the drain port opens, allowing wastewater to be discharged. Once the filter screen is cleaned, the pressure difference drops to its minimum value, and the system returns to its initial filtration state, resuming normal operation.
The filter consists of a housing, multiple filter elements, a backwashing mechanism, and a differential pressure controller. A horizontal partition inside the housing divides its interior into upper and lower chambers. The upper chamber contains multiple filter elements, maximizing filtration space and significantly reducing the filter's volume. The lower chamber houses the backwash suction cup. During operation, the turbid liquid enters the lower chamber of the filter through the inlet and then enters the inner chamber of the filter element through the baffle holes. Impurities larger than the filter element gaps are trapped, while the clean liquid passes through the gaps to reach the upper chamber and is finally discharged from the outlet. The filter uses a high-strength wedge-shaped filter screen, and the filter element is automatically cleaned through differential pressure control and timed control.
When impurities accumulate on the surface of the filter element, causing the inlet-outlet pressure difference to increase to the set value, or when the timer reaches the preset time, the electric control box sends a signal to drive the backwashing mechanism. When the backwash suction cup port is directly opposite the filter element inlet, the drain valve opens, and the system depressurizes and drains water. A negative pressure zone appears between the suction cup and the inside of the filter element, with a relative pressure lower than the water pressure on the outside of the filter element. This forces some of the clean circulating water to flow from the outside of the filter element into the inside, and the impurity particles adsorbed on the inner wall of the filter element are carried into the suction cup and discharged from the drain valve. The specially designed filter screen creates a jetting effect inside the filter element, ensuring that any impurities are washed away from the smooth inner wall. When the pressure difference between the filter inlet and outlet returns to normal or the timer expires, the material flows continuously throughout the process, with minimal backwashing water consumption, achieving continuous and automated production.
The filter is widely used in metallurgy, chemical, petroleum, papermaking, pharmaceutical, food, mining, power, and urban water supply industries. Applications include industrial wastewater filtration, circulating water filtration, emulsion regeneration, waste oil filtration, continuous casting water systems and blast furnace water systems in the metallurgical industry, and high-pressure water descaling systems for hot rolling. It is an advanced, efficient, and easy-to-operate fully automatic filtration device.
