Filter Operation - General Description (Figure 1)
Water enters the filter through the “Inlet” (1) and passes through the coarse screen (2) that
functions as a “first stop” for rough particles. Water then reaches the fine screen (3), which
further purifies the flow by separating smaller particles from the water. As more water flows
through, impurities build up on the fine screen. As impurities on the screen accumulate, a
pressure imbalance is built up between the internal section of the fine screen (3) and its
external section. When the difference in pressure (DP) reaches the preset value in the
electronic control unit (12), a series of events is triggered while the water continues to flow
to the user. The flushing valve (4) opens, pressure is released from the hydraulic piston (5)
and water flows outside. Pressure in the hydraulic motor chamber (9) and the dirt collector
(7) is significantly lowered, and the dirt collector nozzles (8) begin a suction process. The
water flows through the hydraulic motor (9) which rotates the dirt collector (7) around its
axis. The pressure released from the piston (5) and the high pressure inside the filter cause
linear movement of the dirt collector. The combination of the linear movement and rotation
significantly cleans the entire internal screen (3) surface.
The flushing cycle takes about 10 seconds. The flushing valve (4) closes at the end of the
cycle and the increased water pressure returns the hydraulic piston (5) to its initial position.
The filter is now ready for the next flushing cycle, with clean and filtered water flowing
through the “Outlet” (10).
Note: At the back of the piston is an indicator that pops up when the piston reaches the end
of its motion. –this indicator helps us to check whether the dirt collector, inside the filter,
completed it’s motion.
General Description of the Electronic Control System
The electronic system (12) initiates the cleaning process based on either time differential
(DT) and / or pressure indicator differential. The trigger closes a circuit and then triggers the
electronic control unit after a delay of 15 seconds. The electronic control unit (12) controls
the opening and the closing of the flushing valves (4) via the solenoid valve (13). The flushing
cycle, which takes a total of about 10 seconds (can be adjusted by the operator), resumes its
operation whenever the time cycle ends or the difference in pressure reaches the preset
pressure value set in the controller. If the difference in pressure remains unchanged after
one cycle, another cycle will start after a delay of 15 seconds.
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Figure 1: Filter Assembly
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AF800N
