1、 Function and purpose
The ZPG-SD series fully automatic backwash sewage filter is suitable for industrial wastewater treatment processes, steel plant slag flushing water, power plant processes and cooling water, papermaking processes and influent, chemical production processes and irrigation systems, etc. It is used to filter out various hard particles with a particle size of 3500-300 microns in water, ensuring the safe and reliable operation of the system.

2、 Structure and Working Principle
The ZPG-SD series fully automatic backwash sewage filter adopts high-strength stainless steel mesh, which has the characteristics of large processing capacity, long service life, and high cleaning efficiency. This machine adopts intelligent differential pressure control and timed control to automatically backwash the filter screen. When the pressure difference between the inlet and outlet of the filter reaches the set value or the timer reaches the set time, the electric control box sends a signal to drive the valve to rotate, and at the same time, the drain valve opens. At this time, the water flow is forced to enter the outer side of the filter cartridge and the shell interlayer through the inlet section of the filter cartridge, and in the opposite direction, wash away the impurities adhered to the mesh from the outer side of the filter screen to achieve the purpose of cleaning the filter. When the pressure difference between the inlet and outlet of the filter returns to normal or the timer set time ends, the motor stops rotating and the electric drain valve closes. Throughout the entire process, the liquid did not stop flowing, achieving continuous and automated production.

3、 Performance characteristics
Single unit flow rate: 50-1200M3/H, larger flow rates can be connected in parallel by multiple single units
Minimum working pressure: 0.2Mpa
◎ Maximum working pressure: 1.0/1.6/2.5/4.0Mpa
◎ Maximum operating temperature: 80 ℃
◎ Filtration accuracy: 300-3500 microns
◎ Control mode: differential pressure, time, manual
◎ Control box connection voltage: AC 220V
◎ Rated operating voltage: three-phase AC220v /380v、50HZ

4、 Installation parameters

Note: This table only lists some models. 1. Various sizes of caliber filters can be customized according to customer requirements. 2. The parameters in the table are for reference only. The actual size of the equipment is subject to the supply status

5、 Explanation of related terms
1. BackwashThe water flow drives impurities to wash over the filter screen, and the impurities are trapped at the back end of the filter screen. When the equipment enters the discharge state, the backwash valve installed in the filter screen divides the filter screen into front and back ends, and at the same time, the discharge valve at the back end of the filter screen opens, forming a low-pressure state at the back end. The high-pressure water flow intercepted at the front end will impact the back end of the filter screen from the outside to the inside, causing impurities to be discharged from the discharge valve with the water flow (refer to the legend on page 2).

2. Differential pressure controlThe water flow of the equipment is divided into two parts by the filter screen, but the inlet and outlet flow rates are the same. When impurities accumulate in the filter screen, the inlet flow area decreases, resulting in an increase in fluid pressure in the front section of the filter screen and a pressure difference with the outlet. The more impurities accumulate, the greater the pressure difference. The differential pressure gauge component can extract the differential pressure values at the inlet and outlet, and convert them into current signals to supply to the control box to complete the differential pressure switch control.

3. Timed controlAfter the programmable components inside the control box are programmed with control time and activated, the program will automatically start a series of operations according to the preset time, and the control circuit will complete the backwash and sewage discharge process.
(All the charts listed are based on the manual. If you need to know more, please download the manual for reference.)

Fully automatic backwash filter equipped with a strong magnetic water processor: