Automatic backwash strainer working principle:

Automatic backwash strainer, The filtered liquid flow in the housing, filtered by the filter screens, the impurities are trapped inside the filter screens.

when the impurities become more and more, and the pressure difference between the contaminat side and clean side will be increase. When the pressure difference reaches the set value, the differential pressure gauge will signal, and the filter system will start to back wash the filter screens, and then the clean liquid flow out from the housing, the impurities will be discharged by the drain valve.

Automatic backwash strainer working process:

1) The gear motor drive the intermediate shaft and the washing arm do rotation together.the positioning switch control the The rotation angle, and let the point is meet with the cleaned filter screens.
2) Opening the drain valve, and there will be pressure difference between the drain outlet and clean side(outside the filter screens).

3) Because of the pressure difference, the liquid in the clean side will flow to the filter screens inside from the outside of the filter screens, and then the filter system will start to back wash the filter screens, and the impurities will be washed down and discharged from the drain valve.

4)The time of back washing can set by yourself, when the time is up to the setting value, the drain valve will be closed, and back washing process of this group of filter screens is over, and then the next back washing process of other groups of filter screens will be start.

5)When all the filter screens are cleaned, the Zero switch will control the washing arm to original position, and the filter system will stop back washing and continue thefiltration process.
Because the back washing process is proceed one group by one group, so the filter system will keep the filtration working all the time.