STRUCTURAL FF 1 Flashcards
What is the fire triangle made up of?
Fuel, Oxygen, Heat
What does disrupting the fire triangle mean for FFs?
By manipulating or disrupting the triangle, FFs can more effectively control and extinguish structural fires.
What is Pyrolysis?
Pyrolysis is the decomposition of a substance caused by heat.
What is latent heat vaporisation?
The amount of heat required to change a given mass of substance from a liquid to a vapour (eg water to steam)
What is the heat release rate?
The amount of heat energy released over time.
What is a flashpoint?
The lowest temp at which a substance produces a flammable vapour.
What is a Fire point?
The lowest temp at which a substance produces a vapour that can sustain a continuous flame. (usually a few degrees above the flashpoint)
What is an Auto Ignition temperature?
It is the temp at which a fuel will ignite on its own without any additional source of ignition.
What is the flammability range?
The ratio of fuel to air. (LEL-UEL)
The Ideal Mixture is when the ratio of fuel to air that burns with max intensity and efficiency.
Define the neutral plane:
The area between the under pressure (fresh air) and over pressure (hot fire gasses)
What is a gravity current?
Occurs when fresh air is denser than the hot gasses.
What is Thorton’s Rule?
As the fire accesses more O2 or as O2 increases, the heat release rate increases. Can lead to extreme fire behaviour.
What is a ventilation-controlled fire?
Simply put, in a ventilation-controlled fire, fire growth is limited by the available air supply. Can be categorised as vented or non-vented.
What is a fuel-controlled fire?
Fires with more than enough air for combustion. Eg: a free burning fire outside or a small fire in a kitchen pan
What are the four phases of basic fire progression?
- Developing Fire
- Flashover
- Fully Developed
- Decay