TORAY MBR
Instruction Manual
06-G-MB2-NHPAC-220801
18 of 61
Membrane Module
Air Diffuser
FIC
Filtrate Water
Manifold
PIA
Lower Limit Alarm
Air Outlet
Feed
Chemical
FI
L
H
L:
O
PEN
H:
CL
O
SE
L:CLOSE
H:OPEN
VFD or Auto Valve
PIA
(2) Pump Suction Configuration
Fig. IV-3 illustrates the general configuration for pump suction filtration.
Fig.IV-3 Schematic Flow Diagram for Pump Suction Operation
(In the case of NHPA150-2C)
When incorporating a suction pump to facilitate water flow through the membrane, the filtrate
water flow rate should be controlled using a flow meter fitted with control output signals and a
suction pump fitted with a VFD device or an automatic control valve. In the event the
membrane tank water level reaches the designed lower limit, the filtration mode should be
stopped. As with the gravity filtration mode previously discussed, should the membrane tank
water level reach the designed upper limit, the upper limit controller will close the raw water
inlet control valve.
Since the liquid in the tank contains a significant amount of dissolved air, some of that
dissolved air will accumulate in the filtrate pump suction line.
It would be necessary to
periodically purge the filtrate line of any accumulated air and in this context, it is quite
beneficial to locate the pump at the top of filtrate piping.
A range of methods can be
used to remove air from the filtrate line: vacuum pump, ejector, or manual water injection.
Contact Toray or refer to the engineering manual for the additional details.
Raw
Fine Screen
FIC: Flow Rate Indicator/Controller
LS: Level Switch
PIA : Pressure Indicator/Alarm
FI: Flow Indicator
LS