AIRE-064-1-4
14
Membrane Module
Air Diffuser
FIC
Permeate Water
Manifold
dPIA
Upper limit
Air Outlet
Feed chemical
FI
L
H
L:OP
EN
H:CLOSE
L:CLOSE
H:OPEN
line to stop raw water coming.
It is recommended to install enough capacity of the buffer tank (the equalization tank) before
the membrane submerged tank to equalize the raw water flow and enable stable operation.
In this natural water head filtration, the air accumulated in the permeate water line should be
discharged once a day at least, otherwise the effective water head is reduced seriously. The air
purge nozzle should be installed at the highest position of the permeate water line and the
automatic shutter valve (the air purge valve) is recommended to be installed on the line just
before the nozzle. (as shown in Fig.IV-2) Stopping the filtration (fully closing the permeate control
valve) and opening the air purge valve for a few minutes, the air is easily purged. If the piping of
the permeate water line climbs over the tank wall, it is required to build a siphon by the suction
pump after every air purge operation.
(2) Filtration with suction pump
The filtration can be also performed with using the suction pump (see Fig. IV-3).
Fig.IV-3 Schematic Flow Diagram for Pump Suction Operation
Raw Water
Fine Screen
FIC: Flow Rate Indicator/Controller
L S : Level Switch
dPIA:
Different
Pressure Indicator/Alarm
FI
：
Flow Meter
LS
