Fire
A rapid chemical process that produces heat and usually light
Matter
Made up of atoms and molecules
Solids
Most uncontrolled structure fires are fed by solid fuels. Solids have a definite size and shape
Liquid
Assumes the shape of the container in which it is placed and expand when heated and possibly turn into gas.
Gas
A type of fluid that has neither independent shape nor independent volume but rather tends to expand indefinitely
Composition of air
21% oxygen, 78% nitrogen, and 1% oxygen and trace amounts of other gases
Fuels
Materials that store energy
convection
Which method of fire spread involves air currents in a room for building moving the fire around the room?
Convection
The transfer of heat by the flow of gases or fluid from hotter areas to cooler areas
Cool the burning material
Which of the for extinguishing methods is the most common use by firefighters
Flashpoint
The lowest temperature at which a liquid will produce enough vapor to support a small flame for a short period of time
gases, vapors, particles
What are the three major components of smoke?
Vapor density-CO2 has VD of .97 so it mixes easily with all layers of air
What term is used to describe the weight of a gas fuel and measures the weight of the gas compared air? CO2?
Growth phase
With a room and contents fire, which phase of fire development draws additional fuel into the fire
Mechanical energy-water falling over a dam and compressing air into a compressor
What type of energy is converted to heat when two materials rub against each other and create friction and what are two examples?
Class C
Which class fire extinguisher is used to fight a fire involving energized electrical fires?
Rollover/flame over...
flashover
What term refers to the spontaneous ignition of hot gases in the upper levels of a room? What can a rollover indicate?
Thermal layering
What term define the layering of gases as they are heated in an enclosed space?
Oxygen, heat, and fuel
What are the three components of the fire triangle?
Oxygen, heat, fuel, and a chemical chain reaction
What are the four components of the fire tetrahedron
decay phase
Which phase of solid fuel fire development is the period when the fire is running out of fuel?
Pyrolyzed
Solid fuels don't actually burn so they must first be heated or _________ to decompose into a vapor?
Fully developed phase
Which phase of solid fuel fire development produces the maximum release of energy?
Gas
Which state of matter assumes the shape of the container, Will typically expand when heated, and has no independent volume it's?
Boiling liquid expanding vapor explosion(BLEVE)
What occurs when a liquid fuel is stored in a vessel under pressure?
Hydrogen and carbon
Which two elements combined form a hydrocarbon?
Flame point/fire point
What term is used to describe the lowest temperature at which a liquid produces enough vapor to sustain a continuous fire?
Conduction
Which method of fire spread involves the process of transferring heat through matter by movement of the kinetic energy from one particle to another?
Class K
Which class the fire extinguisher is used to fight a fire involving combustible cooking oils and fats in kitchen?
combustion
A Rapid chemical process in which the combination of the substance with oxygen produces heat and light
Oxidation
the process in which oxygen combines chemically with another substance to create a new compound
Pyrolysis
the decomposition of a solid material caused by heat, which breaks down the material to produce a flammable vapor
heat flux
the measure of the rate of heat transfer from one surface to another
temperature
the degree of sensible heat of a body as measured by a thermometer
incipient stage
What is the first stage of fire development? Fire is fuel dependent, not a big temperature increase and not much smoke and gases in this phase also.
growth stage
What is the second stage of fire development? fire is more dependent on the environment and how much ventilation in this stage.
fully developed stage
What is the third stage of fire development? In this phase the fire is consuming the maximum amount of fuel and releasing the most amount of energy.
decay phase
What is the fourth stage in fire development? In this phase the fire is dying due to lack of oxygen or fuel
neutral plane
the level in a compartment opening at which the pressure of hot gases and smoke leaving the compartment and the pressure of the cooler gases entering the compartment are equal
flashover
a rapid transition from the growth stage to a fully developed stage. Needs approximately 1000 degree temps.
backdraft
event caused by the introduction of oxygen into an enclosure where the superheated gases are already hot enough for ignition but don't have enough oxygen. Require a "closed box
smoke explosion
occurs when a mixture of flammable gases and oxygen are present. usually needs cool temperatures and presence of void spaces
flammibility
determined by the component with the lowest ignition temperature
volatility
the ability of a substance to produce combustible vapors
flammability/explosive limits
the upper and lower concentration limits of a flammable gas or vapor in air that can be ignited
smoke volume
this attribute gives some idea of how much fuel is being heated
smoke velocity
this attribute of smoke suggests how much pressure is accumulating in the building
smoke density
this can suggest how much fuel is contained in the smoke
smoke color
this attribute of smoke can give some indication of which stage the fire is in, which substances are burning and possibly the location
laminar smoke flow
a smooth streamlined flow of smoke indicating the pressure in the "box" is not too high
turbulent smoke sloq
an agitated, boiling angry smoke flow indicating the pressure in the "box" is high
black fire
a high volume, high velocity, turbulent, dense black smoke that reaches 1000 degrees and can char steel and concrete
Determine the key attributes
Determine what is influencing the key attributes
Determine the rate of change
Predict the even
What are the four steps in smoke reading?
Smoke on top-clean air on bottom...same level
smoke rises and opening clears out...level above
smoke thins when door opens but stil fills door...level below
explain smoke reading at doorways
21%
Normal percentage of oxygen in the air
greater the resistance, greater the heat
Explain the relationship between heat and resistance
vapor
What stage must fuel be in for combustion to take place?
cooling the burning material, excluding the oxygen, removing fuel, breaking the chemical reaction
What are the 4 ways to extinguish a fire?
composition, amount, configuration
What are the 3 characteristics of solid fuels that need consideration?
by the compound with the lowest ignition temperature
How do you determine the flammability of a mixture?