Learn the practical way of starting a boiler on board a ship. Also know about the precautions that are to be taken before starting the boiler
How to operate a boiler?
The operating procedure of a boiler depends on the type and the manufacturer's instruction. Yet, there are few common points that should be kept in mind while operating any type of boiler on board a ship. So lets get down to some basic boiler operation training and the general procedures for operating a boiler are as follows.
Before starting the boiler
The following things should be checked thoroughly before starting the boiler:
- All the up-takes for the exhaust gases should be checked properly for a clear flow and to prevent any kind of obstacle or diversion.All the dampers should be checked for open position. All the vents should also be kept open.
- All feed water connections, combustion air connections and pressure gauges should be opened or checked for proper working condition
- Alarms should be checked for sound and proper working condition
- The connections to the super heater and those in between the super heaters should be opened fully to prevent any kind of disturbance in the steam flow.
- All the boiler water drains and blow-down cocks should be properly closed.
- The boiler should only be filled with De-aerated water till slightly below the working level
- All the header vents should be closed to prevent water leakage
- Water level in the economizer should be checked and the vents should be shut off after blowing out any trapped air.
- Forced draft fans should be checked for speed and sound. In case exhaust gas air heaters are provided, the connections to the forced draft fans should be diverted.
- Fuel oil system should be checked for any closed valves and the fuel oil should be adequately heated before circulation to prevent any kind of pipe blockage.
- Firstly, the forced draft fans should be started to purge the system to remove any trapped exhaust gases or oil vapours.
- All the air slides at different registers should be checked and closed, except the "lightning up" burner.
- Th operating burner should then be lit for low firing rate and efficient combustion
- The fuel oil flow should be matched with the speed of the fan to ensure a complete combustion with steady flame.
- Once the boiler starts and steam starts coming out of the superheater vents, the superheater header vents should be closed.
- As soon as the pressure reaches 210 kpa, the air drum vents should be closed.
- The working pressure should be brought up gradually to avoid overheating and damage to refractory material .
- After the main and auxiliary lines are warmed through, the drains should be closed.
- All the water level gauges should also be blown through and checked to ensure correct reading.
- The safety valves should be lifted and released when the pressure is 3 bar below the normal operating value.
- Once the operating pressure is reached , the boiler should be put on load and the superheater circulatory valves should be closed.
- All the vents, drains and by passes should also be closed.
The water level in the boiler should be properly checked and the cascade system should be monitored for correct operation.