erensan°
“The Heating Engineer”
- 33 –
280111
Foam control
When foam formation occurs manifesting itself with fluctuations
in water level and unexplained drops in steam temperature,
steam draught should be reduced to restore constant water
level. To remove foam, water level should be returned to
normal level and steam should be discharged at foam level
continuously. The boiler should be fed with fresh water and
foam discharge should be continued until foaming is prevented
and if foaming cannot be prevented, the boiler should be taken
out of operation and the reasons of the problem should be
investigated.
Boiler feedwater control
Boiler feedwater should be sent to the boiler after passing
through a water softener device and undesired conditions
should be removed making constant analyses of the boiler
water.
Boiler feedwater pumps should be kept under observation
during operation and in case a fault arises, the spare pump
should be operated immediately to prevent feedwater cut.
Blowdown
Maintaining the concentration of solids dispersed in the boiler
water (TDS- Total Dissolved Solids) at an acceptable level can
be provided by constantly analyzing the boiler feedwater and
blowing down continuously from the blowdown pipe installed for
this purpose. If water analyses that can determine the
continuous blowdown quantity and duration are not being
made, the boiler should be blown down by opening fully the
lower blowdown valve once every shift. Blowdowns should be
done when steam draught is at minimum.
While blowing down boiler in cases where there are double
valves on the blowdown line, the valve first opened should be
closed last. Blowdown valves must be opened carefully and
slowly.
The blowdown system should be inspected frequently and
leaking valves should be repaired or replaced. Leaks under high
erensan
°
“The Heating Engineer”
- 34 –
280111
pressure or temperature should be removed after burner is
shut and pressure drops.
During high volume blowdowns, the shutting valve should be
opened slowly to its end and then blowdown should be started
turning the valve slowly ½ turn. In this case, blowdown should
be done until the water level in level gage drops 1.5-2 cm. If
more blowdown is required, blow down should be completed
opening the blowdown valve fully after this stage and first the
blowdown valve then the shutting valve should be closed.
THINGS TO BE DONE IN EMERGENCY CONDITIONS
Abnormally low water level
For whatever reason, if the water level in the level gage drops
below minimum, the burner should be stopped immediately and
steam outlet should be closed. Then the reasons for water level
drop should be investigated.
It is very dangerous to feed water immediately and restore a
closed boiler’s water level to its previous state. Water should
be fed under control after the boiler is cooled down to 50
0
C for
some time.
When the reason for the water level dropping is understood and
the fault is removed, the water should be brought to normal
level and then the boiler should be re-fired. In boilers that have
electrical alarm and locking systems, which notify low water
level, these systems should be always kept in good working
order, providing safety against sudden level drops.
PERFORM THE INSPECTION AND
MAINTENANCE OF THE BOILER AND
BOILER ACCESSORIES FULLY
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