Chapter 14 - Reading Smoke Flashcards
Backdraft
An explosive event that occurs when air is suddenly reintroduced into a closed space that is filled with pressurized, ignition-temperature, and oxygen deprived products of combustion and pyrolosis
Black Fire
A slang term for smoke that is high-volume, has turbulent velocity, is ultra-dense, and is deep black; a sign of impending flashover
Explosive Growth Phase
A rapid fire growth phenomenon that occurs when combustion air is reintroduced into a ventilation-controlled fire, leading to smoke flame-over and room flashovers
Flame-over
A hostile fire even that includes the ignition and sustained burning of the overhead smoke layer within a room or hallway
Flashover
A sudden hostile fire event that occurs when all the surfaces and contents of a space reach their ignition temperature nearly simultaneously, resulting in full room fire developmen
Flow Path
An avenue that heat, smoke, flames, and combustion air follow
Ghosting
A hostile fire event warning sign that is characterized as the intermittent ignition of small pockets of smoke; usually seen as fingers of flame that dance through the upper smoke layer
Hostile Fire Event
A fire behavior phenomenon that can suddenly harm firefighters, including explosive growth phase, flashover, backdraft, smoke explosion, and flame over
Pyrolysis
Also referred to as Pyrolitic Decomposition, the chemical breakdown of compounds into other substances by heat alone
Smoke
The products of incomplete combustion and pyrolysis including aggregate of particles, aerosols, and fire gases that are toxic, flammable, and volatile
Smoke Explosion
A hostile fire even that occurs when a spark or flame is introduced into a pocket of smoke that is below ignition temperature but above some aggregate flashpoint.
Concept
Societal changes (the way we build buildings and the types/volumes of contests we put in them) have led to more severe content and structure fires with more flashover entrapments
Smoke
The products of incomplete combustion and pyrolysis that include an aggregate of particulates, aerosols, and gases
Six phases of fire
Ignition, initial growth, ventilation-limited, explosive growth, fully developed, and decay
Fire growth concept
The explosive growth phase is often triggered by firefighters opening a door to make entry for fire attack
Flow paths
Avenues that convection heat and combustion air travel
Cause of smoke igniting
Triggered by two influences that meet. Right temperature (as low as 450F) and right mixture (flammable range that can be as wide as 1-74% in fuel to air)
Hostile Fire Events
Smoke explosion, flame-over, flashover, explosive growth, and backdraft
Smoke Explosion
Spark induced momentary ignition of a smoke pocket distal to the actual fire
Flame-over
Ignition of the upper heat layer and exhaust flow path
Flashover
Simultaneous ignition of all surfaces and contents in a room due to radiant heating
Backdraft
Sudden detonation of oxygen deficient smoke products within a closed, pressurized space upon the reintroduction of air
Warning signs of hostile fire events
Smoke explosion - Increasing pressure in trapped smoke away from a growing fire
Flame-over - Ghosting, smoke flow paths that are moving faster than firefighters can crawl
Flashover - Turbulent smoke that has filled a room, ghosting, exterior vent-point ignition
Explosive growth - Puffing and sucking of smoke at open doors and windows
Backdraft - Closed pressurized box with signs of extreme heat, puffing and sucking of smoke at cracks and seams, yellowish/gray smoke
Four attributes of smoke
Volume, velocity, density and color
Definition of smoke attributes
Volume - tells little about a fire but provides an impression regarding the potential size
Velocity - Turbulent velocity indicates serious heat, and that a flashover looms
Density - Indicative of the severity of hostile events
Color - Tells the level of heating that is present. Black is hot, white is cool.
