Fire science
No description yet. This curated deck is ready for daily study.
Card preview (24)
Fire science What is the definition of combustion?
An irreversible chemical reaction producing heat and light
Fire science Name the things required to make up the ‘triangle of fire’?
• fuel • heat • oxygen
Fire science Name the three states in which matter can exists?
• solid • liquid • gas
Fire science Name the SI unit that measures heat energy?
joules (J)
Fire science Heat is spread in three ways, what are they?
• convection • conduction • radiation.
Fire science What is the term used to descried a substance that contain oxygen “Lock-up” within its structure which is then released to allow combustion?.
Oxidising agent
Fire science To extinguish a fire it is necessary to break one of the legs on the triangle of fire how can this be achieved?
• cooling • starving • smothering.
Fire science What is a Flash Point?
The lowest temperature at which sufficient vapours are produced for a momentary flash to occur when an ignition source is introduced. But there are insufficient vapours for it to continue burning once the ignition source is removed
Fire science What is Fire Point?
The lowest temperature at which sufficient vapours are produced for the fuel to ignite and continue to burn once an ignition source is introduced.
Fire science What is meant by the term Auto-ignition temperature?
The lowest temperature at which a fuel will ignite and continue to burn without the need for an ignition source
Fire science What do the initials LEL stand for and explain there meaning?
lower explosive limit. Below a fuels LEL it will be too lean to burn
Fire science What do the initials UEL stand for and explain there meaning?
Upper Explosive Limit. Above this the mixture will be too fuel rich to burn
Fire science Describe what the ‘flammable range’ of a fuel is?
The ‘flammable’ range is between the LEL and the UEL and it is the percentage mixtures of fuel and air that are capable of being ignited
Fire science Describe the 4 classes of fire, class A,B,C and D ?.
• Class A - Carbonaceous • Class B - Liquids and Liquefiable Solids • Class C - Gases and Liquefied Gases • Class D - Metals
Fire science What colour is a “diffused” flame?
red & yellow
Fire science What is meant by the term ‘pyrolisis’?
Pyrolisis is the decomposition of a substance by heat which can produce flammable gases
Fire science Define a flashover?
A sudden and sustained transition of a growing fire into a fully developed fire
Fire Science What are the signs of a flashover?
• Intense heat forces crews low • Flames in gas layer • Lowering of neutral plan • All exposed surfaces pyrolising
Fire Science What actions should you take when dealing with a flashover?
• Pulse spray into ceiling , cool gases • Stay low • Consider withdrawing and fire fight from out side • Consider ventilation
Fire science What are the signs of a flashover?
• intense heat forces crews low • flames in gas layer • lowering of neutral plan • all exposed surfaces pyrolising
Fire science What actions should you take when dealing with a flashover?
• pulse spray into ceiling , cool gases • stay low • consider withdrawing and fire fight from out side • consider ventilation
Fire Science What are the external signs of back draught ?
• Fire burning for some time • Fire gases being pushed out under pressure from gaps • Windows blackened with no visble sign of flame • Fire gases (smoke) pulsing out from gaps
Fire Science What are the internal signs of backdraught ?
• Low neutral plane • Darkening of fire gases • Inrush of air & fire gases being forced out through openings • Pulsation of fire gases through openings • Deflagration through the opening
Fire science Define the term “Backdraught”?
The explosive or rapid burning of heated gases that occurs when oxygen is introduced into a building or compartment that has not been properly ventilated and has a depleted supply of oxygen due to fire