Danfoss iSave 40, Руководство по эксплуатации

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Operation guide | iSave 40
27
180R9239 | AQ299555093252en-001601 | iSave 40 | 09.2022
10.2.3 Daily system shutdown
1. The system is running in normal operation and
producing permeate flow.
2. Stop the high-pressure pump (4).
3. Keep the iSave unit (11) running until the
wanted pressure (5) at the membranes is
reached and the TDS in the high-pressure line
is equal to the TDS in the low-pressure line.
When “HP in” is below 15 bars/217 psig,
the maximum operation period is
10 minutes. If the pressure (10) at “HP in”
drops below 3 bars/43.5 psig, the sound
will change of the iSave. This is due to
cavitation. Also see Data sheet for iSave.
If possible run the iSave at maximum
750 rpm.
4. Stop the iSave unit (11).
5. Stop the seawater supply pump (1).
10.2.4 2-14 days system shutdown
1. Run the “daily system shutdown” procedure.
2. Supply fresh water to the iSave unit (11) and
the SWRO system. Make sure that the iSave
unit and the SWRO system are filled at the
same time to ensure optimal flushing.
3. Run the system while the iSave unit is running,
until all seawater is discharged.
When “HP-in” is below 15 bars/217 psig,
the maximum operation period is
10 minutes. If the pressure (10) in “HP-in”
drops below 3 bars/43.5 psig, the sound
will change of the iSave. This is due to
cavitation. Also see Data sheet for iSave.
If possible, run the iSave at maximum
750 rpm.
4. Stop the iSave unit (11).
5. After the iSave has stopped rotating, stop fresh
water supply.
10.2.5 Long-term system shutdown
For a long-term shutdown period, the SWRO
system including the iSave unit must be
thoroughly flushed with fresh water to remove
any salt. Run the “daily and 2-14 days system
shutdown” procedure.
Further, any biological growth should be
prevented.
Make a final flush of the iSave unit with the same
solution used to preserve the SWRO membranes.
Flush both the high-pressure and low-pressure
sides of the iSave (11). The high-pressure flush is
performed by circulating the solution through
the iSave unit and the membranes by rotating
the iSave unit.
If possible, run the iSave at maximum
750 rpm.
10.3 Membrane cleaning of the RO system
with iSave unit
Below procedures are general guidelines for the
membrane cleaning of SWRO-systems with the
Danfoss iSave. Procedure details may differ
depending on the system design.
The purpose of membrane cleaning is to reduce
scaling and fouling in the membranes. For
optimal performance specific chemicals are
required, depending on the cause of the
contamination.
After chemical treatment the system must be
flushed with fresh water. The flushing water,
coming out of the membranes, may consist of a
large amount of suspended inorganic particles. It
is important to assure that these particles are not
fed into the iSave.
It is recommended to disconnect the
piping from the “HP-in” of the iSave and
flush the contaminated water from the
membranes directly to drain. By discon-
necting the pipes there will be no
accumulation of contaminations in the
HP-piping and HP-valves. See P&ID no 2.
10.3.1 Membrane cleaning
The procedures below are based on Dow’s
Cleaning and Sanitization: Cleaning steps
described in Dow’s Form No. 609-02090-1005.
Other procedure may be used depending on the
membranes used.