Fire Science

Front 1

Fuel exists in matter of three states ?

Back 1

Fuel. Liquid. Gas/vapor.

Front 2

What is pyrolisis

Back 2

Heating solid fuels and chemically breaking them down by passing the liquid stage which emit toxic flammable gasses

Front 3

Classes of fire

Back 3

A.comb solids B. Flam liquids C. Flam gasses D. Comb metals E. Electrically energized F. Fat/oils

Front 4

Extinguishing methods x4

Back 4

Smothering .cutting of o2 supply

Starving . Removal of fuel

Cooling. Removing temp

Interrupting chemical chain reaction

Front 5

What is the combustion process

Back 5

Self sustaining chemical reaction involving oxidation producing heat and light

Front 6

What is the lfl

Back 6

Lowest amount of fuel in the air that supports combustion e.g too much air not enough fuel

Front 7

What is ufl

Back 7

Fuel is above the maximum concentration above which combustion cannot take place. E.g too much fuel not enough air

Front 8

What is ideal mixture

Back 8

Concentration of fuel and air that will burn with most intensity due to fuel and air at ideal mixtures

Front 9

What does heat cause

Back 9

Causes pyrolisis/decomposition resulting in production of ignition vapors or gases

Causes continuous production of ignition fuel vapours

Front 10

What is spontaneous heating

Back 10

Known as self heating a chemical reaction between two materials without an external heat source

Front 11

What is composition of smoke

Back 11

Gas vapours dispersed solid particles

Front 12

Chemical reaction of combustion produces what

Back 12

Heat light smoke flammable vapours

Front 13

What is a flash point

Back 13

Lowest temp at which a vapours is given off by a liquid to flash if ignited

Front 14

What is fire point

Back 14

Lowest temp at which sufficient vapours is given off by a liquid to enable combustion if ignited

Front 15

Ignition temp

Back 15

Lowest temp of which a substance can sustained combustion can be initiated

Front 16

Auto ignition temp

Back 16

Minimum temperature at which a substance will ignite without a pilot flame

Front 17

Spontaneous ignition temp

Back 17

Lowest temp at which a substance will ignite without an ignition source

Front 18

Specific heat

Back 18

Amount of heat required to heat 1kg by 1degree

Front 19

Latent heat of vaporization

Back 19

Amount of energy absorbed when 1kg of liquid is converted into gas at boiling point

Front 20

What is the expansion ration of

1ltr of water at 100 degrees

1ltr of water at 500

Back 20

1700

3400

Front 21

What is latent heat

Back 21

Heat energy required to change a substance from liquid gas and solid doesn't involve rise in temp just change of state

Front 22

What are the fire development stages x4

Back 22

Incipient

Growth

Fully developed

Decay

Front 23

What happens during incipient

Back 23

Ingredients of combustion come together.

Fire may go out if triangle is split

Front 24

What happens in growth phase

Back 24

Begins with self sustaining combustion

Growth rate depends on ventilation

Front 25

What is fully developed

Back 25

All fuel is consumed

Fire burns with high release rate

Duration depends on amount of fuel

Front 26

Decay phase ?

Back 26

Starts once 80% of fuel is consumed

Heat declines until all fuel is consumed

Begins when fire passes back from ventilation controlled fire to fuel controlled

Front 27

Factors that affect fire development x5

Back 27

Size and number of ventilation openings

Ceiling height

Size volume of thermal properties

Size of fuel

Temperature

Front 28

What is HRR

Back 28

Temperature that develop in a burning compartment are result of energy released

Front 29

HRR HAS AN AFFECT ON X5

Back 29

Flame height . Transition to flash over . Fixed safety design considerations . Smoke generation . Fire room temperature

Front 30

Methods of fire transfer x5

Back 30

Convection . Conduction . Radiation .ember transfer . Direct burning

Front 31

What is a flash over

Back 31

Transition point between growth phase and fully developed phase of fire . Occurs when all fuel items in compartment ignite

Front 32

What temp does flash over reach prior and during

Back 32

Prior 60sec 500-600

During 800-1000

Front 33

What are warning signs of flash over x4

Back 33

Rapid increase in compartment temp . Dancing angels. Combustible fumes giving off pyrolisis . Smoke rapidly backing down to floor

Front 34

Safety precautions for flash over x7

Back 34

Always be aware of possible flash over . Ppe and ba. Additional branch covering entrance . Protect escape routes . Check doors for signs of heat . Stay low. Controlled bursts from branch directed at hot gases .

Ventilate when safe to do so or OIC says

Front 35

How to control a flash over x3

Back 35

Briefed on tactics chosen by oic

Ventilate compartment

Cool over pressure zone

Front 36

What is a backdraught

Back 36

Sudden eruption of fire in an under ventilated compartment due to the introduction of fresh air

Front 37

Warning signs of a back draught x7

Back 37

Smoke puffing around windows and doors. Black smoke and soot stained windows . Excessive heat. Windows rattling . Muffled sounds in compartment . Confinement of fire . Thick black smoke logging compartment . Sudden inrush of air

Front 38

Safety precautions of backdraughtx6

Back 38

Ppe. Doors closed and cover with charged branch . Stay out of room if possible. Cool compartment .keep clear of escaping steam and hot gases. Stay low and to side of door

Front 39

How to prevent a backdraught

Back 39

Prevent o2 from entering and wait for compartment to cool.

Cool environment .

Remove flammable vapours