YAMIT AF-9800 Series Service Maintenance Manual page 5

AF9800
Filter Operation General Description
Filtration
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.
Cleaning Process
When the difference in pressure (ΔP) reaches the preset value on the
differential pressure indicator, Or when the preset time in the controller
arrives, a series of events is triggered while water continues to flow to the
system units. The controller transmits a signal for a 15 second flushing cycle.
The solenoid opens the flushing valve (4), and release the pressure from the
hydraulic piston (5). Water flows outside from the flushing valve (4). Pressure
in the hydraulic chamber (6) and the dirt collector (7) is significantly lowered
resulting in a suction process via the suction nozzles (8) to the dirt collector (7)
and from there to the hydraulic chamber (6) through the flushing valve (4)
outside. The electric motor (9) simultaneously rotates the dirt collector (7)
around its axis. The pressure is released from the piston (5) and the high
pressure inside the filter causes linear movement of the dirt collector. The
combination of the linear movement and rotation efficiently cleans the entire
internal screen (3) surface.
At the end of the 15 second cycle the flushing valve (4) closes and the
operation of the electric motor (9) is stopped. The increased water pressure
returns the hydraulic piston (5) to its initial position. The filter is now ready for
the next cycle, with clean and filtered water flowing through the "Outlet" (10).
The 15 second flushing cycle resumes operation whenever the difference in
pressure reaches the preset pressure value set on the differential pressure
indicator. Or when the preset time in the controller is triggered on. If the
pressure difference remains unchanged after one cycle, another cycle will start
after a delay of 10 seconds
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