YAMIT AF-9800N Series Service Maintenance Manual page 5

AF9800N
Filter Operation General Description (Figure 1)
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.
5