MELBURY HE 3800-10000 -
Installation, Use and Maintenance
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410821-V11
- Internal pressure with the unit of more than 1 bar
cold.
- Remove leaky (permeable) components that are
letting out more gas than as if they were sealed.
If the guidelines above are followed, the unit's system
water has the proper characteristics to last a long time:
8.2 < pH < 9.5 with a water concentration of < 0.1 mg/l.
If there is a chance that oxygen could enter the unit,
you must take additional precautions. Adding an
oxygen scavenger (ex. sodium sulphite) is highly
recommended. We recommend directing any water
treatment questions to specialists, which can provide:
- The appropriate treatment based on the
characteristics of the unit,
- A monitoring agreement with a guarantee as to the
results.
For units in which
the water comes into contact with
heterogeneous materials
, such as copper or
aluminum,
appropriate treatment is recommended
in order to ensure that the unit will last. In most cases,
this consists of adding corrosion inhibitors (in the form
of chemical solutions) to the unit. Referring to a water
treatment specialist is recommended.
Setting up a filtration system
A filtration system on the back of the boiler is
recommended in order to remove suspended particles
Choice of burner / boiler
from the unit.
We recommend adopting modulating burners to avoid
thermal shock in operation.
Hydraulic
Set up an effective degasser as close as possible to
the boiler outlet to evacuate the air from the networks
introduced during the filling and the addition of water
in order to maintain a good convection coefficient.
Add an additional expansion vessel if the characteris-
tics of the pressure maintenance unit do not allow the
pressure variations to be limited to 0.5 bar in order to
limit the variations in hydraulic pressure.
Respect the minimum flow rates recommended.
(chapter 2.5.1. - 2.5.2.)
Unit monitoring
If the recommendations listed above (new installation
or renovation) have been followed, the unit monitoring
is limited to:
- Checking the amount of make-up water (fill water
make-up water volume < 3 times the unit
volume)
- Checking the pH level (stable or slightly increasing)
- Checking the total hardness (stable or slightly
decreasing)
We recommend monitoring these parameters two to
three times a year. Note: Monitoring the quantity of
make-up water is critical to the long life of the unit.
If any of these parameters deviates from the above
recommendations, refer to a water treatment specialist
to correct the problem.
Setting up a plate exchanger
If the recommendations listed above cannot be met, you
can set up a plate exchanger to separate the primary
system from the secondary system, which protects the
boiler from undesirable effects.
Exploitation
The frequency of cold starts should be as low as
possible; during these periods, the flue gas temperature
can be low and cause condensation that is detrimental
to the life of the boiler; it is recommended not to exceed
a cold start per week.
During a cold start, the heat emitters of the installation
will be irrigated when the set temperature is reached;
the temperature rise of the installation will be carried
out at minimum power.
Do not shut off the burner at full load to avoid
temperature shock.
Do not hesitate to add buffer volumes to the plant's
hydraulic system to avoid short operating cycles,
especially when the boiler is protected by an isolation
plate heat exchanger. Regarding the regulation of the
installation, we recommend burner modulation
parameters (PID) sufficiently slow to ensure stability
and low temperature variations, start / stop differentials
/ hysteresis must be reasonable in order to leave a
range of operation sufficient for the burner and to
ensure its modulation (value +/- 4 ° C). All strategies
must allow the burner to be started up for an average
operating time of 30 minutes.
The temperature variations of the boiler must be as low
