DIVEX MHE-02, Инструкция по установке, эксплуатации и обслуживанию

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KI-OM-523 R2 Chapter 1
1.3.2 FLUID SYSTEM
The MHE-02 may function with either salt water or fresh water as the heating medium. The
unit is provided with two inlets for fluid, one for fresh water and one for sea water. The fresh
water line is typically used for flushing the system after use. The freshwater line is fitted with
a check valve to prevent salt water contamination of the fresh water supply. The unit uses
small inexpensive immersion heater elements mounted in the flange plate of the stainless
steel heater tank to heat the fluid. The flow rate of the fluid through the heating tank is
governed by the action of the bypass valve.
The flow rate of fluid from the heater tank to the divers is determined by the motor speed and
the ratio of the pulley set used to couple the motor to the pump. The pump is a positive
displacement pump and is designed and supplied with a pulley arrangement to provide a
flow rate of
30 litres/min .
The fluid to be heated enters the unit at the assigned inlet and flows through a manifold and
a quarter-turn hand valve. The manifold is equipped with analogue temperature and
pressure gauges to provide operator feedback on the fluid supply. The fluid is then piped to
two separate inlet filters. The two filters may be isolated using hand valves on the inlet and
outlet of each filter. Only one filter should be used under normal operation with the other on
standby and ready to be put into operation. These filters clean input water of particulate
matter down to 50µm in order to protect the piston pump and umbilical coupling from being
damaged and prevent clogging of the heating water tubes in the diver suits. The inlet filters
are each fitted with pressure gauges in order to monitor pressure drop across the filter and
indicate the condition of the filter cartridge. A pressure regulating valve fitted after the filter
IMPORTANT
The calculated required temperature rise may be indicated on the heater bank
selection schedule as a maximum for one configuration and a minimum on the
subsequent selection of heater banks. In this case practical application will dictate
which configuration should be used. The higher capacity configuration is usually
used to allow for better control.
If the bypass dump valve remains fully open during normal operation, indicating
heating over-capacity then the lower kW heater configuration should be used to
improve control and unit performance.
If the bypass valve remains fully closed during normal operation, indicating heating
under-capacity or a possible heater bank fault then a higher kW configuration
should be used to improve control.
IMPORTANT
Fluid supply to the unit by the vessel must be maintained above 30 litres/min at 3
bar for correct operation.