Chapter 6 Reading Smoke

Question 1

Define Backdraft

Answer 1

AN explosive event that occurs when air is suddenly reintroduced into a closed space that is filled with pressurized, ignition-tempature, and oxygen deprived products of combustion and pyrolysis

Question 2

Define Black fire

Answer 2

A slang term for smoke that is high-volume, has turbulent velocity, is ultra-dense, and is dep black; a sign of impending autoignition and flashover

Question 3

Define explosive growth phase

Answer 3

A rapid fire growth phenomenon that occurs when combustion air is reintroduced into a ventilation-controlled fire, leading to smoke flame-over and room and/or hallway

Question 4

Define flashover

Answer 4

A sudden hostile fire event that occurs when all the surfaces and contents of a space reach their ignition temperature nearly simultaneously, resulting in a full-room fire involvement

Question 5

Define flow path

Answer 5

An avenue that heat, smoke, flames, and combustion air follow

Question 6

Define ghosting

Answer 6

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

Question 7

Define hostile fire event

Answer 7

A fire behavior phenomenon that can suddenly harm firefighters; events include explosive growth phase, flashover, backdraft, smoke explosion, and flame-over

Question 8

Define pyrolysis

Answer 8

Also referred to as pyrolytic decomposition, the chemical breakdown of compounds into other substances by heat alone

Question 9

Define smoke

Answer 9

The products of incomplete combustion and pyrolysis; it includes an aggregate of particles, aerosols, and fire gases that are toxic, flammable, and volatile

Question 10

Define smoke explosion

Answer 10

A hostile fire event that occurs when a spark or flame is introduced into a pocket of smoke that is below ignition temperature but above some aggregate flashpoint. The result is a split-second ignition and rapid expansion of that pocket with no sustained burning

Question 11

What are the four key attributes of smoke?

Answer 11

volume, velocity, density, color

Question 12

What two sources is smoke developed?

Answer 12

incomplete combustion, pyrolitic decomposition

Question 13

Define aerosols

Answer 13

suspended or propelled liquid

Question 14

Define off-aggregating

Answer 14

releasing a mix of particulates and aerosols as well as gases
slang term is off gassing

Question 15

3 things smoke is made up of

Answer 15

particulates, aerosols, gases

Question 16

Carbon that can support flaming

Answer 16

Soot

Question 17

Define Ash

Answer 17

Trace metals and minerals (depleated salts) that can no longer support flame

Question 18

Related to reading smoke define colors of carbon (soot) in smoke vs Ash in smoke

Answer 18

carbon adds flat dry black color

ash adds dirty white color

Question 19

What are the primary liquids in smoke?

Answer 19

moisture and hydrocarbons

Question 20

What gives smoke a satin wet color?

Answer 20

Hydrocarbons

Question 21

List the gases that are present in smoke that affect fire behavior?

Answer 21

CO, Hydrogen cyanide, benzene, acrolein, hydrogen sulfide

Question 22

Smoke is ignitable as low as ___ degrees and flammable range of ___ to ____

Answer 22

450F, 1 to 74% in air

Question 23

Define piloted ignition

Answer 23

smoke gases below ignition temp but above flashpoint needing only a proper air mix and sudden spark or flame to complete ignition

Question 24

What can tell the ISO what is about to happen in a structure fire?

Answer 24

Smoke flow

Question 25

What are the factors of a six-phased growth model (vent controlled model)

Answer 25

size of individual compartments type, quantity, and continuity of fire load presence or lack of smoke and fire control systems available flow paths through adjoining compartments and the exterior of the building size and status of exterior openings

Question 26

What are the phases of ventilation-controlled fire?

Answer 26

``` ignition phase initial growth phase ventilation-limited phase explosive growth phase fully developed phase decay phase ```

Question 27

Event that brings together heat, fuel, and oxygen to start the self-sustaining process of combustion

Answer 27

Ignition phase

Question 28

fire growth phase controlled by the proximity of burning fuels to other burnable fuels. pyrolysis begins and smoke production become abundant

Answer 28

initial growth phase

Question 29

Phase of compartmentalized fire condition where open flaming decreases due to smoke displacing available combustion air

Answer 29

Ventilation-limited phase

Question 30

Phase of rapid fire growth that occurs when combustion air is reintroduced into a ventilation-controlled fire leading to smoke flame over and flashover

Answer 30

Explosive growth phase

Question 31

Phase of total flame involvement of the interior flow paths

Answer 31

Fully developed phase

Question 32

Phase of available fuels consumed and fire begins to wane

Answer 32

Decay phase

Question 33

What are the hostile fire events?

Answer 33

flashover, backdraft, smoke explosion, and flame over

Question 34

Define flame over

Answer 34

ignition and sustained burning of the overhead smoke layer within a room and/or hallway

Question 35

What typically originates at the seat of the fire and travels along the heat flow path

Answer 35

Flame over

Question 36

Which direction does flames travel in a ventilation limited flame over?

Answer 36

Toward the seat of the fire along the heat flow path

Question 37

Event that typically occurs in an area away from the fire such as a dead-end hallway, top of a stairwell, an uninvolved room above the fire or a void space

Answer 37

Smoke explosion

Question 38

Difference between a explosive growth event and backdraft?

Answer 38

backdraft is instantaneous and explosive growth event occurs over 10 - 90 seconds

Question 39

What are the warning signs of flashover?

Answer 39

turbulent smoke flow that has filled a compartment Ghosting Vent-point ignition (exterior autoignition) Rapid change in smoke volume and velocity

Question 40

What are the warning signs of Backdraft

Answer 40

yellowish gray smoke emitting from cracks and seams bowing, black stained windows closed pressurized box with signs of extreme heat puffing from the cracks and seams of a closed box

Question 41

What are the warning signs of a smoke explosion

Answer 41

Smoke that is being trapped in a separate space above the fire signs of a growing fire signs of smoke starting to pressurize

Question 42

What are the warning signs of a flame over?

Answer 42

Increase in smoke speed Ghosting Laminar flow of smoke that is becoming turbulent Smoke flowing from hallways and stairways faster than a ff can move

Question 43

What are the four distinctive characteristics for smoke?

Answer 43

Volume, velocity, density, and color (VVDC)

Question 44

What are the two forces that cause smoke to pressurize

Answer 44

convection heat, smoke volume

Question 45

Volume pushed smoke does what outside the fire building?

Answer 45

it will immediately slow down and balance with outside airflow