Operation; Standstill; Maintenance; Cleaning - Bitzer K033N Série Mode D'emploi

speed of up to about 1.5 m/s. However, positive experi-
ence must first have been gained from comparable ap-
plications.
Pressure test / test operation
A pressure test should be carried out with a closed
coolant circuit (maximum operating pressure: 10 bar).
With an open circuit a short test run is sufficient.
Corrosion
If the plant is not operated for a long time after pressure
test or test run, the pipes must be protected against
corrosion by:
• pressure test with clean water or dry gas,
• test run with clean water.
If this is not possible, the pipes must be cleaned: Flush
pipes and dry them or fill them with clean water.
Running-in time with open cooling circuits (corrosion
protection)
Within the first months, coolant should constantly flow
through the pressure vessel so that a protective layer
can be built up. During the shut-off periods, a low flow
rate is sufficient.

6 Operation

The pressure equipment must be checked at regular in-
tervals by qualified and authorised staff. The test inter-
vals depend on the mode of operation. They must be
defined by the system operator.

6.1 Standstill

NOTICE
!
!
Risk of corrosion!
During shut-off periods, the coolant side of the
pressure vessel must be protected against cor-
rosion! This applies especially with aggressive
coolants, e.g. brackish water, water containing
solids or liable to biofouling.
Any contamination of the coolant pipe system should
be removed before any long shut-off periods. This ap-
plies especially in cases of organic materials and shell
deposits. With aggressive or corrosive coolants, the
pipe system must be cleaned and dried or filled with
clean water.
DB-200-5

7 Maintenance

The pressure vessels are designed for a maintenance-
free operation. However, it is advisable to clean the
coolant pipes regularly. The contamination depends dir-
ectly on the quality of the coolant used.
• Materials in the coolant in dissolved or solid form can
deposit in the pipes, e.g. lime, sand, algae or silt.
• Organic materials such as algae can build up local
elements. In the worst case, this can lead to pitting.
• With seawater cooling, shells can also grow on the
insides of the pipes.

7.1 Cleaning

WARNING
The pressure equipment is under pressure!
Serious injuries are possible!
Depressurise the pressure equipment!
Wear safety goggles!
WARNING
Coolant can burn skin and eyes
Wear safety goggles!
Suitable cleaning methods and cleaning intervals de-
pend on the type and extent of contamination.
NOTICE
!
!
Risk of corrosion!
Cleaning agent must not react with the pipe ma-
terial!
• Soft deposits such as algae or silt: Brush off care-
fully. Use cleaning agent if necessary. Rinse well af-
terwards.
• Solid coatings, such as lime or shells: Rinse with
suitable solvent. The use of citric acid is very effect-
ive and environmentally friendly:
– Fill with a 25% citric acid / water solution.
– Allow to react for 24 hours. Occasional circulation
by pumping increases the effect.
– Afterwards, flush the released materials out of the
pressure vessel.
Dispose of contaminated coolant properly!

7.2 Extracting the refrigerant

• For repair work at the liquid receivers or when de-
commissioning them, extract or pump down the refri-
gerant as a liquid if possible.
• Dispose of the refrigerant properly.
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