When the filter works, the water to be filtered enters by the water outlet, flows through the filter screen, enters the pipeline required by the user through the outlet for process circulation, and the particle impurities in the water are intercepted in the filter screen. Such a continuous cycle, more and more particles are trapped, the filtration speed is getting slower and slower, and the imported sewage is still flowing into, the filter hole will be smaller and smaller, resulting in a pressure difference between the inlet and outlet, when the tolerance difference reaches the set value, the differential pressure transmitter transmits the electrical signal to the controller, the control system starts the drive motor through the transmission component to drive the shaft to rotate, At the same time, the sewage outlet is opened and discharged from the sewage outlet. When the filter screen is cleaned, the pressure difference is reduced to the minimum value, the system returns to the initial filter, and the system operates normally. The filter consists of a shell, a multi-element filter element, a backwashing mechanism, and a differential pressure controller. The transverse partition in the shell is divided into the upper chamber and the lower chamber, the upper chamber is equipped with a plurality of filter elements, so as to fully filter space and significantly reduce the volume of the filter, and the lower chamber is installed with a backwash suction cup. When working, the turbid liquid enters the lower chamber of the filter through the entrance, and then enters the inner chamber of the filter through the partition hole. Impurities greater than the gap of the filter element are trapped, and the net liquid passes through the gap to the upper chamber, and finally is sent out from the outlet. The filter adopts high strength wedge filter screen, and the filter element is automatically cleaned by pressure difference control and timing control. When the accumulation of impurities in the filter on the surface of the filter element causes the inlet and outlet pressure difference to increase to the set value, or the timer reaches the preset time, the electric control box sends a signal to drive the backwashing mechanism. When the backwashing suction plate port is directly aligned with the inlet of the filter element, the drain valve will be opened. At this time, the system will relieve pressure and drain, and a negative pressure zone with relative pressure lower than the water pressure outside the filter element will appear on the inside of the sucker and the filter element, forcing part of the net circulating water to flow into the inside of the filter element, and the impurity particles adsorbed on the inner wall of the filter element will enter the pan with the water flow and be discharged from the drain valve. The specially designed filter screen creates a spray effect inside the filter element, and any impurities will be washed away from the smooth inner wall. When the filter inlet and outlet pressure difference returns to normal or the timer set time ends, the whole process, the material does not stop flowing, the backwash water consumption is less, and the continuous and automated production is realized. Filters are widely used in metallurgy, chemical industry, petroleum, paper, medicine, food, mining, electricity, urban water supply fields. Such as industrial wastewater, circulating water filtration, emulsion regeneration, waste oil filtration treatment, metallurgical industry continuous casting water system, blast furnace water system, hot rolling with high pressure water descaling system. It is an advanced, efficient and easy to operate automatic filter device.

The water to be treated by the filter enters the body by the water inlet, and the impurities in the water are deposited on the stainless steel filter screen, resulting in a pressure difference. The pressure difference of inlet and outlet is monitored through the pressure difference switch. When the pressure difference reaches the set value, the electric controller gives the hydraulic control valve to drive the motor signal. After the equipment is installed, the technician will debug, set the filtration time and cleaning conversion time, the water to be treated will enter the body from the water inlet, and the filter will begin to work normally. When the preset cleaning time is reached, the electric controller will give the hydraulic control valve and drive motor signals to trigger the following actions: The motor drives the brush to rotate, cleaning the filter element, while the control valve is opened for sewage discharge, the whole cleaning process only lasts for tens of seconds, when the cleaning is finished, the control valve is closed, the motor stops rotating, the system returns to its initial state, and begins to enter the next filtration process. The inside of the shell of the filter is mainly composed of coarse filter screen, fine filter screen, suction pipe, stainless steel brush or stainless steel nozzle, sealing ring, anti-corrosion coating, rotating shaft and so on.

A simple filter is formed by dividing the container into upper and lower cavities with filter media. The suspension is added to the upper chamber, and under pressure enters the lower chamber through the filter medium to become filtrate, and the solid particles are trapped on the surface of the filter medium to form filter slag (or filter cake). During the filtration process, the filter slag layer accumulated on the surface of the filter medium gradually thickens, the resistance of the liquid through the filter slag layer increases, and the filtration speed decreases. When the filter chamber is full of filter slag or the filtration speed is too small, stop filtering, remove the filter slag, and make the filter medium regenerate to complete a filtration cycle.

The liquid must overcome the resistance through the filter slag layer and the filter medium, so there must be a pressure difference on both sides of the filter medium, which is the driving force to achieve filtration. Increasing the pressure difference can accelerate the filtration, but the deformed particles are easy to block the pores of the filter medium when the pressure difference is large, and the filtration slows down.