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Explain the fire triangle
heat causes matter to offgas and it is the offgassing that ignites
A rapid chemical reaction that produces a release of energy in heat and light
What are the 3 byproducts of combustion?
Define smoke and what elements can be found within smoke.
- Smoke is a visible product of incomplete combustion
- O2, Nitrogen, CO, CO2, carbon, fine soot
How does heat transfer?
Heat transfers to cold
What are 3 methods of heat transfer?
- - conduction
- - Radiation
- - Convection
Normal combustable material
Cooking oils and fats
What are the 4 phases of fire?
- Fully developed
What is the difference between Flashover and backdraft?
- Flashover - There is an abundance of O2 present and typically takes place during growth or fully developed fire
- Backdraft - There is a lack of O2 present until you open a window or door, typically in the later stages of fire
Is puffing smoke is a sign of possible flashover or backdraft?
Lowest temperature which a substance will give a suficient vapour to ignite
- Also known as Ignition temperature
- Lowest temperature which a substance will give a suficient vapour to sustain fire
What makes a substance flammable?
- Any liquid having a flashpoint below 38 degrees celcius and a vapour pressure not exceeding 175KPA
- (ex. gasoline)
What makes a substance flammable?
- Anything with a flashpoint above 38 degrees celcius
- (ex. Diesel)
The higher the vapour desity, the faster the substance offgasses
LEL / LFL?
Lower explosion limit / Lower Flammable limit
UEL / UFL?
Upper explosion limit / Upper Flammable limit
What are the 4 important factors when reading smoke?
What is matter?
- Made up of Atoms and Molecules
- 3 states of matter: Solids, Liquid, Gasses
Define a solid?
- - under normal conditions it retains a definate size and shape
- - contracts when cooled and expands when heated
- - may turn to a liquid
Define a liquid?
- - will assume shape of container
- - most contract when cooled, expand when heated
- - may turn to a solid or a gas
Define a gas?
- - tends to expand indefinitely
- - may liquify
What is a fuel?
A form of energy
Mechanical Energy is...
- converted to heat when two serfaces rub together to create heat
- - waterfall,
A chemical reaction that causes an exothermic or endothermic reaction (release or absorb heat)
Light energy is...
- electromagnetic waves traveling as thermal radiation, a form of heat
Nuclear energy is...
- Fission or fusionwhich release large amounts of heat energy
Oxygen combining with something to form a new compound (ex. Rust)
Oxygen combining with something creates a rapid chemical process creating heat and light (fire)
Decomposition of a material brought about by heat in the absence of oxygen
- Incomplete combustion due to a lack of oxygen
- - solids
Transfer of heat through matter by movement of kinetic energy from one partical to another
Circulatory movement that occurs in gas or liquids with areas of differing temperatures oweing to the variation of density and the action of gravity.
Transfer of heat through the emmission of energy in te form of invisible waves
What are the 4 ways to put out a fire?
- 1. Cool the burning material
- 2. Exclude oxygen
- 3. Remove fuel
- 4. Interupt the chemical reaction with a flame inhibitor
What are the stages of a solid fuel fire?
- 1. Ignition
- 2. Growth
- 3. Fully developed
- 4. Decay
What stage is Flashover possible?
- - AKA rollover
- Hot gasses rise up to the ceiling and when they reach a sufficient temperature they quickly ignite. burn and fall back down and get sucked back into the fire
Describes the amount and the ease of ability of the liquid to evaporate to create a flammible vapor-air mixture
Weight of a gas as compaired to air
- Boiling liquid, expanding vapour explosion
- - BIG propane tanks
- - liquid boils & expands, relief valve opens, liquid levels fall to a point of the proper mixture then BOOM!
Laminar Smoke flow?
Relaxed, smooth smoke flow
Turbulent smoke flow?
Agitated, boiling or angry smoke flow
- high volume, high velocity, turbulent, ultra dense black smoke
- Very hot, impending flashover
If you open a door and the smoke thins but is still in the doorway...
You are above the fire
If you open a door and the smoke dissappears into the room...
You are below the fire
If you open a door and the smoke exits the top half of the door and clean air is sucked in the bottom of the door...
You are on the fire floor