Scavenge Fires Flashcards
with reference to scavenge fires
State FOUR possible contributing factors
- Worn or Damaged Piston Rings
- Defective Fuel Injectors
- After Burning
- Incorrect Fuel Burning
- Dirty Scavenge Space
Explain how EACH factor mentioned contributes
Worn or Damaged Piston Rings
- This will allow lubricating oil and unburnt fuel to pass from the combustion chamber into the scavenge space.
- This oil-fuel mixture can ignite in high temperatures.
Defective Fuel Injectors
- Poor atomization of fuel leads to incomplete combustion.
- That unburnt fuel has a chance to enter the scavenge space and ignite.
After Burning
- When combustion continues after the exhaust valve has opened, it can lead to hot gases or flames entering the scavenge space.
Incorrect Fuel Burning
- Happens due to poor fuel quality, incorrect timing or injector issues.
- This results in carbon deposits and unburnt fuel entering the scavenge space.
State FOUR indications of a scavenge fire
- High Exhaust Temperature
- Black Smoke Leaking the Funnel
- Turbocharger Surging
- Loss of Power
Describe the actions to be taken by EOOW on discovering a scavenge fire
INITIAL SCAVENGE FIRE
1), Inform Bridge
2), Reduce Engine Speed/Load
3), Lift Fuel Pump to Affected Unit
4), Cylinder Lubrication Increased
5), Coolant should be maintained
6), Drains to be shut to prevent flow of sparks in engine room
- Fire should be extinguished after some time.
IF FIRE SPREAD TO OTHER UNITS/SCAVENGE MANIFOLD
1), Inform Bridge
2), Stop Engine
3), Stop Fuel Supply
4), Open Indicator Cocks and Engage Turning Gear to prevent engine seizure
5), Engine Cooling and Lubrication to be Maintained
6), Close Ventilation
7), Release Fixed Firefighting System or CO2
State TWO dangers of allowing a scavenge fire to exist
- Can Spread to Other Units or Scavenge Manifold
- Crankcase Explosion
- Can Spread to ER
with reference to scavenge fires
State FOUR actions to be taken by EOOW on discovering one engine unit only affected
1), Inform Bridge
2), Reduce Engine Speed/Load
3), Lift Fuel Pump to Affected Unit
4), Cylinder Lubrication Increased
5), Coolant should be maintained
6), Drains to be shut to prevent flow of sparks in engine room
with reference to scavenge fires
State FOUR actions to be taken by EOOW on discovering several engine unit affected at the same time
1), Inform Bridge
2), Stop Engine
3), Stop Fuel Supply
4), Open Indicator Cocks and Engage Turning Gear to prevent engine seizure
5), Engine Cooling and Lubrication to be Maintained
6), Close Ventilation
7), Release Fixed Firefighting System or CO2
Explain the procedure to be carried out before the scavenge space on a large two stroke diesel engine is entered for inspection
TREATED AS AN ENCLOSED SPACE
1), Risk Assessment
2), Permit to Work
3), Tool Box Talk
4), Isolate the Space (engine)
5), Open the Doors and Ventilate the Space (at least 24hrs)
6), Rope Off the Area
7), Ensure Standby Team and Emergency Equipment
8), The Atmosphere Should be Tested with a Gas Detector (Hydrocarbon, Combustibles and Oxygen Levels) (21% for Oxygen)
9), Personal Alarms Should be Worn
10), Communications Should be Established
State FOUR items that would be inspected inside the scavenge space
- Piston Rings
- Piston Crown
- Cylinder Liner
- Stuffing Box
- Piston Skirt
- How Clean it is
State FOUR important factors which contribute to initiation of scavenge fire
- Worn or Damaged Piston Rings
- Defective or Dripping Fuel Injectors
- After-burning in the Cylinder
- Accumulation of Oil and Carbon in the Scavenge Space (dirty scavenge space)
Sate the duties of the EOOW on discovering a scavenge fire
INITIAL SCAVENGE FIRE
1), Inform Bridge
2), Reduce Engine Speed/Load
3), Lift Fuel Pump to Affected Unit
4), Cylinder Lubrication Increased
5), Coolant should be maintained
6), Drains to be shut to prevent flow of sparks in engine room
- Fire should be extinguished after some time.
IF FIRE SPREAD TO OTHER UNITS/SCAVENGE MANIFOLD
1), Inform Bridge
2), Stop Engine
3), Stop Fuel Supply
4), Open Indicator Cocks and Engage Turning Gear to prevent engine seizure
5), Engine Cooling and Lubrication to be Maintained
6), Close Ventilation
7), Release Fixed Firefighting System or CO2
