Pressure Exchanger - Grundfos BMS Series Service Instructions Manual

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8.3 Pressure exchanger

Warning
Before starting work on the product, make sure
that the power supply has been switched off and
that it cannot be accidentally switched on.
Fault
1. Excessive sound
pressure level.
2. Excessively high
recovery in the SWRO
system.
3. High salinity in the
high-pressure seawater
feed stream.
4. The low-pressure flow
is lower than the high-
pressure flow which
entails mixing and high
SWRO feed water
salinity.
5. Stalled rotor (no
audible rotation).
6. Low reject flow.
16
Possible cause
a) The pressure exchanger operates above the
rated flow rates on the low-pressure side,
high-pressure side or both.
b) The pressure exchanger pump operates with
little or no backpressure.
c) Air in the system.
a) The BMS hs is operating at a flow rate that is
too high.
b) Increased salinity or raw-water temperature. Adjust flow rates in the system. See section
a) Unbalanced system.
b) A jammed or stalled rotor short-circuits the
high-pressure reject water with the high-
pressure feed water. No exchange occurs;
no audible rotation.
a) Operating pressure exchanger pumps below
the rated flow rate results in low rotor
rotation and increased mixing.
b) Malfunctioning and/or stalled BMS hp pump. Check the rotation, operation, flow rates and pressures
a) The system operates above the rated
pressure or below the rated flow capacity.
b) Debris or foreign particles in the device.
c) The system is not properly flow-balanced.
a) Excessive pressure losses through the
SWRO system.
b) Malfunctioning and/or stalled BMS hp pump. Check the operation, flow rates and pressures of the
Remedy
Immediately reduce the flow rate by adjusting the BMS
hp pump and control valve (V2). Rebalance the system
as described in section
Startup
installation and operation instructions (publication
number 98567337).
To increase the system capacity, add the pressure
exchanger pump(s) in parallel to the existing pumps.
Increase the backpressure by adjusting the low-
pressure reject-water valve (V3).
Rebalance the system as described in section
the BMS hp, BMS hs installation and operation
instructions (publication number 98567337).
Vent the system.
Check that the main BMS hs flow rate does not exceed
the membrane array production capacity for a given
temperature, salinity and fouling factor.
in the BMS hp, BMS hs installation and
system
operation instructions (publication number 98567337).
See section in the BMS hp, BMS hs installation
Startup
and operation instructions (publication number
98567337).
See fault number 5.
Increase and balance the flows through the pressure
exchanger pump. Do not exceed the recommended
maximum flow rates. To increase the system capacity,
add pressure exchanger pump(s) in parallel to the
existing pumps. See section
Startup
BMS hs installation and operation instructions
(publication number 98567337).
of the BMS hp pump.
See section in the BMS hp, BMS hs installation
Startup
and operation instructions (publication number
98567337).
Contact Grundfos Service.
See section in the BMS hp, BMS hs installation
Startup
and operation instructions (publication number
98567337).
Contact Grundfos Service.
BMS hp pump.
in the BMS hp, BMS hs
in
Startup
BMSX
in the BMS hp,