Tetra Pak Hoyer Frigus 400, Руководство пользователя

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7-10
Tetra Pak
Hoyer
F40 03 GB 00
CAUTION:
All repairs and inspections of the refrigerating plant
must be performed exclusively by a qualified
refrigerator technician.
Condensation
Coolant exiting the refrigerator compressor is
condensed in the plate condenser by water, which
may come from the water supply (or a well, or a
circuit with a cooling tower). The Frigus 600 has a
series of condensers with pressure valves which are
factory set and keep condensation pressure at the
optimal value (12 - 13 bar). If water from a water
tower is used, it should be kept at the same tempe-
rature at all seasons, if possible (with a fan in the
tower controlled by a thermostat) so as to keep the
performance of the refrigerating plant uniform.
The condenser must be kept clean to ensure correct,
efficient operation of the machine. All heat taken out
of the ice cream mix and all energy consumed by
the compressor to transfer this heat are transferred
out of the system (in the cooling water) through the
condenser. If the condenser is dirty, it will be difficult
to get rid of the heat, and the freezer may not cool
down sufficiently and may consume excess energy.
Decreased efficiency of the condenser is normally
due to the combined action of particles of dirt in the
flow of water and substances which have separated
from the water (present even in very clean water).
Dirt particles, if large, will obstruct the passage of
water; substances which separate from water and
deposit on the exchange surfaces will obstruct the
passage of heat.
7.2.3 Maintenance of the refrigerating plant
The electrical system is conceived, designed and
developed to provide maximum protection for the
continuous freezer components.
When a motor stops due to overload, a red light
comes on to indicate that a thermal switch has been
tripped.
If the thermal is tripped again when it is reset, the
problem or short circuit persists and it will be
necessary to inspect the electrical system and
possibly block mechanical components.
7.2.2 Maintenance of the electrical system
If the motor compressor on the refrigerating plant
shuts down, check the pressure switch and
electronic protection (located in the terminal board
above the motor compressor). This must be done
before working on the electrical system. Pay careful
attention to the wiring diagram.
The numbered terminal board appearing in the
diagram mirrors the board installed on the freezer
to make it easy to control it. Maintenance and repair
operations should be performed by a qualified
electrician.
Preventing soiling of the condenser
Prevent problems caused by dirt by keeping dirt
out of the condenser. If cooling water comes from a
circuit in which it is impossible to prevent entry of
foreign particles (such as leaves, blades of grass or
tiny insects in water from a tower or sand in well
water), it will be necessary to decant and separate
out these particles.
As specific protection for the freezer, one or more
filters may be installed at the water intake to stop all
particles over 1 mm (largest dimension). The size
and type of filter must be determined according to
the amount and type of dirt in the water.
To prevent efficiency from being decreased by
substances separating out of the water, first analyse
the water to determine what treatment would be
best. All waters tend to corrode or scale the surfaces
with which they come into contact; it is very difficult
to achieve and maintain a balanced condition in
which there is neither corrosion nor scaling.
The trend to corrode or scale depends on the type
and amount of substances dissolved in water, the
acidity of the water and the temperature at which it
is used. It is recommended that users contact a
specialist firm capable of recommending and
supplying batching devices, substances, and
procedures suited to the specific cooling water
system in use.
This is particularly important in the case of water
towers, where temperature, evaporation and
continual ventilation with air in the environment can
generate waters which are particularly polluted (by
solid particles, algae, mineral salts, micro-organisms,
gases, etc.) and damaging for the entire plant and
the condenser in particular.