Keeping a slave boiler pressurized.
In a two-boiler system it’s often a problem to keep the slave boiler at
operation pressure when the steam demand is low. This problem does not appear
when the vessel is loading or unloading in a harbor since those operations
normally need both boilers. On the other hand, when the ship is at sea and only
one oil-fired boiler is used then the slave boiler tends to cool down far below
the required stand by conditions.
Different methods have been used to solve this problem. Installing steam
heating coils in the bottom of the boiler is one method and a sophisticated
start-and-stop method for the slave boiler’s burner to keep the pressure
at desired level is an other.
These installations will be unnecessary if you happen to have an exhaust gas
economizer.
Just connect the exhaust gas economizer to the slave boiler instead of the
master boiler. This operation method will guaranty normal operation pressure on
both boilers all the time at sea.
The method has been used in many ships and the chief engineers are satisfied
with the result.
|
