Fire Development-Fire Dynamics Chap2 Flashcards
Compartment fire development has four stages?
1
Incipient
Growth
Fully developed
Decay
T/F
Fires will pass through all four stages.
1
False
It is important to know that while most fires will pass through all four stages some fires may not.
Example Arson fire may begin in the Growth stage.
Also, some fires may pass through some stages more than one time example, A fire in the decay stage may redevelop into growth stage following Ventilation.
What is the earliest stage of compartment fire development and begins with the actual ignition. 1.1.1.
Incipient stage
Radiant heat, warms the adjacent fuels and continues the process of
Pyrolysis
In the ——— stage, there’s plenty of oxygen and fuel available to burn resulting in temperature in the room may only slightly increase. 1.1.2.
Incipient stage
Incipient fires can be readily extinguished with the use of?
1.1.2
Proper fire extinguisher.
It is essential to recognize that the transition from Incipient Fire into the growth stage —— depending on the type and configuration of fuel involved 1.1.2
Can occur quickly
Sometimes in seconds
What stage is it?
The period that usually begins when the original fire spreads to additional materials. 1.2.
Growth stage
What stage of a fire has plenty of oxygen and fuel available to burn? 1.2.2.
Growth stage
PS incipient stage is the same
What stage of the fire do you have rollovers and flashover occur?
1.2.3
Growth stage
After a compartment fire has flashed over, the fire that remains WITHIN the compartment which has flashed over is considered to be in the ——— stage. 1.3.1
Fully developed stage
( full room involvement)
What stage is it when all available fuel is consumed or when the oxygen concentration falls below
—-% and flaming combustion is diminished. 1.4.
Decay stage
Fuel limited or ventilation limited
Falls below 15%.
It is important to note the cause for any fire in the decay stage is because the fire is either? 1.4
Fuel limited
or
Ventilation limited
What are 2 terms used to describe thermal layering of gases?
2.1.1
Heat stratification
Thermal balance
Thermal layering inside a compartment fire is further broken down into two separate categories, which are? 2.1.2.
Upper layer
Lower layer
T/F
The TIC can identify the thermal interface if the camera itself is positioned in the Lower layer looking at the upper layer. A camera held in the hot layer will not be able to see the thermal interface. 2.1.2.
True
(Lower to Upper)
The boundary between the upper and lower layers which is represented by a sharp transition from the hot smoke in the upper layer to the cool ambient air of the lower layer is called? 2.4.1.
Thermal interface
Don’t confuse it with
interface height
The vertical distance from the floor of the enclosure to the thermal interface is known as?
2.4.2
Interface height
—————- ———— occurs when the flow through the opening flows in ONE direction only
(either into or out of the open)
2.5 point
Unidirectional flow
——— ——- occurs when an opening act as both an inlet and outlet for flows at the same time
2.5.1
Bidirectional flow
—— —— is the horizontal line along a window or door or other ventilation opening where no flow occurs due to the equality of internal or external pressures 2.5.2
Neutral plane
The horizontal line between the inflow and outflow at a ventilation opening example at the plane where there is zero pressure difference and thus zero flow in or out of the opening is known as? 2.5.4.
Neutral plane
The neutral plane is different from the thermal interface because the neutral plane only occurs at?
Page 2-8 Note
Ventilation opening
Neutral plain indicates —— —— at an opening and may be used by firefighters outside the building to help determine the fire location within a building.
Page 2-8 Note
Pressure differences
Thermal interface and interface height referred to the separation between the hot upper layer and the cool lower layer within compartment. Thermal interface, and the interface height indicate—— ——- (how much volume of a compartment is filled with heat). 2.5.5
Heat differences
Thermal interface and interface height referred to the separation between the hot upper layer and the cool lower layer within a compartment. Thermal interface and the interface height indicate heat differences. It may be used by firefighters to identify how far the hot upper layer has banked down and the possibility of ——-. 2.5.5.
Flashover
Smoke. Two of the most toxic gases are —— and ——— which are both chemical asphyxiants and are responsible for many fire deaths. 3.2.
Carbon monoxide
Hydrogen cyanide
Smoke. The combination of fire gases produced during combustion and present in smoke are flammable and contribute greatly to rapid fire development. For this reason firefighters shall consider smoke as? 3.3.
Additional fuel
What are the five characteristics of smoke? 3.5
Volume
Velocity
Density
Color
Stratification
What is another word to describe smoke flow that is smooth? 3.5.2.
Laminar
What are the two descriptions of smoke flow 3.5.2
Laminar ( smooth)
Turbulent
Smoke flow can be either laminate or turbulent based on two things? 3.5.2.
Velocity and temperature
Cooler smoke appears to flow ——-.
3.5.2
Smoother
Hotter smoke will appear to boil and move quickly upwards in a —— fashion. 3.5.2.
Turbulent
Turbulent smoke indicates?
3.5.2 a.
Extreme heat
Laminar smoke indicates? 3.5.2 B.
Low heat
Either because it’s small fire or the smoke is remote from the fire and has cooled
Smoke density.
A large fire which is severely ventilation limited, will produce?
3.5.3
Large volumes of thick, dense smoke.
Smoke density
Dense smoke can indicate the fire is a 3.5.3
Ventilation- limited fire
The 4 colors of smoke are?
3.5.4.
Black
Brown
Grey
White
Black dark smoke indicates ———— conditions, due to restricted air supply ventilation limited. 3.5.4.
Fuel rich
PS when flaming or smoldering combustion occurs the carbon in the fuel is released as soot in the smoke, resulting in a very dark color.
Brown smoke can indicate the early stages of ——- of timber products.
3.5.4
Pyrolysis
Brown smoke color. In a wood framed building, the presence of brown smoke may indicate? 3.5.4.
That the structure is involved
Grey smoke indicates that at least some flaming —— or —— is present.
3.5.4
Combustion or smoldering combustion
In a building issuing dark smoke from some areas and gray smoke from other areas, usually the areas with gray smoke are? 3.5.4.
Remote from the fire
Application of water to a large fire will generate large amounts of steam, which can mix with smoke and create condensation that gives the appearance of? 3.5.4.
White smoke
T/F
White smoke has a very low fuel content .
3.5.4
False
White smoke can have a very high fuel content (white ghost) , represents a significant danger, and should never be treated lightly. When white smoke mixes with oxygen and finds an ignition source there is a potential for a very sudden and powerful ignition.
Smoke Stratification.
A high interface could indicate the fire is in ——— stages of development or that you are remote from the fire area.
3.5.5 B1.
Early
Smoke stratification
A sudden rise in the interface could indicate that? 3.5.5 B2.
Ventilation has occurred
Smoke stratification.
Gradual, lowering of the interface often indicates a buildup of hot fire gases, a situation that could progress to? 3.5.5.
Rollover AND flashover if left uncontrolled
Smoke stratification.
A sudden —— of the interface could indicate a rapid intensification of the fire. 3.5.5.
Lowering
Smoke stratification.
A neutral plane that is at or near floor level may indicate? 3.5.5 B5.
The fire is on a floor below.
Flow path management.
The shape and position of the smoke air track at a vent opening can be an important indicator of? 4.3.
Intensity of the fire
T/F
Velocity and direction
Smoke or flame being discharged from the entire ventilation opening (neutral plain visible) usually indicates that it is an outlet and that there is at least one inlet located somewhere else in the structure. 4.4.2.
False
NO neutral plain visible
