Steam is required on a vessel for different purposes ranging from propulsion in steam turbine vessels to heating and operating whistle. Boilers are used to produce steam on a vessel.
What is a Marine Boiler?
A Boiler can be defined as a pressure vessel in which water or other liquid is heated to evaporate and generate steam, the generated steam is then super-heated to high pressure for use external to itself.
Types of Boilers used in ships?
In the marine industry, there are two common types of boilers in use namely: the water-tube boilers and the fire-tube boilers. The most commonly used of the two is the water-tube boilers in which water is passed through lines of tubes where it is heated by a burner or a furnace.
Uses/Application of a boiler on a ship
Depending on the type and size of a ship, boiler usage and application may differ. Ships that runs on steam turbine requires steam to operate. Boilers are used on a ship to generate steam. Apart from usage for propulsion (on steam turbine vessels), there are other applications of steam.
Other Uses of Steam on a ship
- Used in tankers ships to drive cargo pumps for oil transfer
- Used to drive Winch and windlass
- Used for warming-up the engine in cold areas prior to starting
- Used for blowing soot
- Used for making the accommodation warm during cold seasons
- Used to drive derrick on some ships
- Used for ships whistle operation on steam ships and others
- Used for heating heavy fuel oil and lubrication oil
- Used for cargo heating by driving stripper pumps
What is boiler mounting?
Boiler mountings are devices directly fitted to the boiler shell and it includes:
- Steam stop valve
- Safety valve
- Salinity cock or test cock
- Feed check valve
- Air vent cock
- Two gauge glass level indicators
- Scum blow down valve
- Man hole doors
- Bottom blow down valve
Safety devices on a marine boiler
- Water level indicators
- Safety valve
- Low / high water level alarm and shut down
- Pressure gauge
- Low fuel oil pressure alarm
- Low / high fuel oil temperature alarm
- Flame failure alarm
- Low / high steam pressure alarm
- Smoke density alarm
- Force draught fan stop alarm