Terms Flashcards
Definition of terms
Fire
TN 106.4 Flow path
A rapid oxidation process, which is a chemical reaction resulting in the evolution of light and heat in varying intensities.
Heat Energy
TN 106.4 Flow path
is a form of energy characterized by vibrations of molecules and capable of initiation and supporting chemical changes and changes of state
Temperature
TN 106.4 Flow path
a measure of the degree of molecular activity of a material compared to a reference point. Temperature is measured in degrees Fahrenheit or degrees Celsius
Heat Release Rate (HRR)
TN 106.4 Flow path
the rate at which fire releases energy - also know as power. HRR is measured in unit of Watts (W), which is an international system unit equal to one joule per second.
Heat Flux
TN 106.4 Flow path
the rate of heat energy transferred per surface unit area - kW/m2
Conduction
TN 106.4 Flow path
heat transfer within solids or between contacting solids
Convection
TN 106.4 Flow path
heat transfer of gases or liquids, through natural movement from higher pressure areas to lower pressure areas- (buoyancy)
Flashover
TN 106.4 Flow path
the transition phase in the development of a contained fire in which surfaces expose to the thermal radiation, from fire gases in excess of 600 degree C, reach ignition temperature more or less simultaneously and fire spreads rapidly through the space. this is the most dangerous stage of fire
Backdraft
TN 106.4 Flow path
a phenomenon that occurs when fire takes place in a confined area and burns undetected until most of the oxygen within is consumed. The heat continues to produce flammable gases mostly CO. These gases are heated above their ignition temperature. When a supply of oxygen is introduced, as when normal entry point are opened, the gases could ignite whith explosive force.
Flowpath
TN 106.4 Flow path
the movement of fire and is byproducts.
Flameover (Rollover)
TN 106.4
a condition in which unburned fuel fro the originating fire has accumulated in the ceiling layer to a sufficient concentration that it ignites and burns.
flameover can occur without ignition of or prior to the ignition of other fuels separate from the origin
