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Introduction What is scavenge fire

Causes

Indications

Putting off fire

Preventive measures

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Questions State the common causes of scavengefires

List the indication that a scavenge fireis in

progress State the immediate action to be taken in the

event of a scavenge fire

List with reasons the checks and precautionsnecessary before an engine is put back in toservice following a scavenge fire.

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What is Scavenge Fire Fire in the

scavenge space of

a diesel engine iscalled scavengefire.

Scavenge fire is

caused by ignitionof carbon depositsin the scavengespace.

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What is Scavenge Fire serious damage can

be done to the

piston rod and the scavenge air

box walls, the latterpossibly causing a

reduction in thetension of thestaybolts.

Stay bolts

C S Fi

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Causes o Scavenge FireThe fire triangle

Build up of depositsCylinder oilUn-burnt fuel

Crankcase oil

Blow by

Scavenge air

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Indications Increased exhaust

temperature of effected

cylinder Turbocharger may

surge Scavenge manifold is

hot Engine slow down due

to reduced power

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Putting off fire Reduce speed to slow and

request bridge for permission

to stop. Stop auxiliary blower Stop fuel oil supply to engine

Put the scavenge manifold fireextinguishing system in to

operation to kill the fire.

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Fire Extinguishing System for Scavenge

Air Space

Fire in the scavenge air space can beextinguished by

steam, or

water mist or CO2.

Steam pressure: . 3-10 bar

Freshwater mist pressure: min 3.5 bar

CO2 .. 150 bar Open extinguishing agent to adjacent

cylinder as well to prevent spread offire.

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Putting off fire After fire remove dry deposits

and sludge from scavengespace.

Clean and inspect all thepiston rods and cylinder liners.

Check the alignment of pistonin the liner.

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Prevention of fire Clean scavenge trunking and drains

Scavenge ports clean

Piston rings and liner wear Cylinder oil feed rate with in limits

Stuffing box sealing rings and scarper

rings Fuel injection equipment in good

condition and correct injection timing

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Summary What is scavenge fire

Causes

Indications

Putting off the fire

Prevention