Danfoss MPE 70, Руководство по эксплуатации

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Operating guide | MPE 70
16
180R9426 | AQ367027814446en-000801 | IOM MPE 70 | 08.2022
6.7 Flushing
RO membranes require periodic flushing to
limit biological fouling.
There are two types of flushing: feed water
(Seawater) flush and fresh water (Permeate)
flush.
Regardless of the flush water used, the water
must be pre-filtered to the level described in
chapter 6.8. All parts of the MPE 70 must be
flushed, i.e. LP- and HP flow channels.
It is required to flush with permeate:
• After chemical treatment
• For stops lasting more than 1 day the
MPE 70 must be rotated during
permeate flush
• Before long time shut down
It is required to flush with fresh sea water
prior to every shut down , to remove brine in
the MPE70.
Operating at low pressure should be
limited. Operating at low pressure causes
cavitation but is not critical, it is not
recommended to operate at this state for
longer than 30 min.
Failing to flush the MPE 70 with fresh
water before extended shutdowns
may result in extensive biological
growth and cause corrosion in the
MPE 70 and other equipment in the
RO system.
6.8 Seawater quality
6.8.1 Pre-filtration
It is important that the incoming water is
filtered according to the specification given
in the data sheet appendix 11.1 to assure
optimum service life. A true graded density
melt-blown depth filter cartridge is recom-
mended. Poor pre-filtration of the feed
water will result in reduced service life of the
MPE 70.
The MPE 70 may request a different
pre-filter of the seawater than the HP
pump and other components in the
RO system.
It is important to use a proper filter
housing that allows a good seal
between housing and filter cartridge.
If there is a high risk of water by-pass it
is recommended to use a second stage
filter solution.
As the various filters on the market
differ greatly, Danfoss High Pressure
Pumps recommends using cartridges
with consistent, reliable performance
and high efficiency, in which fibres are
blown continuously onto a central
support core.
Danfoss High Pressure Pumps does not
recommend cartridges requiring any
type of binders or resins.
For more information on the importance
of proper filtration, please consult our
data sheet “Filter solutions for high-pressure
pumps and ERDs”, which also will provide
you with an explanation of filtration defini-
tions and guidance on how to select the
right filter.
6.8.2 Chemicals
The MPE 70 can be flushed with biocide
like the membranes. The biocide must be
compatible with the materials used in the
MPE 70. MPE 70 material can be found in the
parts list, appendix 11.4.