Transcript Basic Principles of: 1

Basic Principles of:
1
1.1 The firefighter shall define heat and fire.
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1.2 The firefighter shall define the fire triangle
and tetrahedron.
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1.3 The firefighter shall identify two (2) chemical,
mechanical, and electrical energy heat sources.
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1.4 The firefighter shall define the following
stages of fire:
a) Incipient
b) Flame spread
c)
Hot smoldering
d) Flashover
e) Steady state
f)Basic
Clear orObjectives
free burning
g) Back draft explosion
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1.5 The firefighter shall define the three (3)
methods of heat transfer.
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1.6 The firefighter shall define the three (3)
physical states of matter in which fuels are
commonly found.
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1.7 The firefighter shall define the hazard of
finely divided fuels as they relate to the
combustion process.
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1.8 The firefighter shall define:
a) Flash point
b) Fire point
Basic
Objectives
c) Ignition
temperature
d) Upper and lower explosive limits
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1.9 The firefighter shall define
concentrations of oxygen in the air as it
affects combustion.
 1.10 The firefighter shall identify three
products of combustion commonly
found in structural fires which create a
life hazard.
 1.11 The firefighter shall identify
characteristics of water as it relates to
its fire extinguishing potential.
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Basic Objectives
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The firefighter shall define heat and fire:
Heat - a form of energy characterized by vibration of molecules and capable of initiating
and supporting chemical changes and changes of state.
Fire - a rapid oxidation process with the evolution of light and heat in varying intensities.
The firefighter shall define the fire triangle and tetrahedron::
Fire triangle - Fuel, heat and an oxidizing agent (air) are components which are necessary to sustain
combustion
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Fire tetrahedron –The combustion reaction can be
characterized by four components: The fuel the oxidizing
agent, the heat and the uninhibited chemical chain reaction.
These four components have been classically symbolized by a
four-sided solid geometric form called a tetrahedron.
Heat
Fuel
This is the
Fire Triangle
Oxygen or Oxidizing agent
Uninhibited Chemical
Chain Reaction
Fires can be prevented or suppressed by controlling or
removing one or more of the sides of the tetrahedron.
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Fire is a chemical process known as combustion. It is
frequently described as the rapid oxidation of
combustible material accompanied by a release of energy
in the of heat and light. There are four products of
combustion:
• Heat -
Most responsible for the spread of fire.
Direct cause of burns, dehydration, heat exhaustion, and respiratory
injuries.
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Fire is a chemical process known as combustion. It is
frequently described as the rapid oxidation of combustible
material accompanied by a release of energy in the of heat
and light. There are four products of combustion:
• Heat -
Most responsible for the spread of fire.
Direct cause of burns, dehydration, heat exhaustion, and respiratory injuries.
• Light -
Flame is the visible, luminous body of a burning gas.
When burning gas is mixed with the proper amounts of
oxygen, the flame becomes hotter and less luminous.
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Fire is a chemical process known as combustion. It is
frequently described as the rapid oxidation of
combustible material accompanied by a release of
energy in the of heat and light. There are four
products of combustion:
• Heat • Light -
Most responsible for the spread of fire.
Direct cause of burns, dehydration, heat exhaustion, and respiratory injuries.
Flame is the visible, luminous body of a burning gas. When burning gas is mixed with
the proper amounts of oxygen, the flame becomes hotter and less luminous.
• Smoke -
The smoke encountered at most fires consists of a mixture of oxygen,
nitrogen, carbon dioxide, carbon monoxide, finely divided carbon particles
(soot), and miscellaneous assortment of products that have been released from
the material involved.
Liquid fuels, oil, tar, paint, rubber, and sulfur generally give off dense, black
smoke.
Some materials burn with virtually no smoke such as alcohol and charcoal.
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Fire is a chemical process known as combustion. It is frequently
described as the rapid oxidation of combustible material
accompanied by a release of energy in the form of heat and light.
There are four products of combustion:
• Heat
• Light
• Smoke
• Gasses Gasses are produced by the pyrolysis of the material being burned. They are what’s
really burning during a fire. Some fire gases may not completely burn and can produce
a lethal atmosphere.
Carbon monoxide is produced by the incomplete combustion of a burning material.
Hydrogen chloride combines with the moisture in the lungs to produce hydrochloric
acid. It is a gaseous by-product of the burning of many plastics including polyvinyl
chloride (PVC).
Hydrogen cyanide can be produced in the burning of wool, nylon, polyurethane
foam, rubber, and paper. It is a chemical asphyxiant and interferes with the ability of
the body tissues to use oxygen.
Nitrogen oxides are produced by the decomposition of pyroxylin plastics, plastics
frequently used to make drafting tools, rulers, etc. Forms nitric acid in the lungs and
can lead to fatal pulmonary edema. May not be apparent for several house after
exposure.
Phosgene is produced from the burning of Freon® and other refrigerants. It is a
strong lung irritant and may not be evident for several hours after exposure. It forms11
hydrochloric acid in the lungs.
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The firefighter shall define the following stages of fire:
1. Incipient:
Is the earliest phase of a fire beginning with the actual ignition.
The fire is limited to the original materials of ignition.
The oxygen content in the air has not been significantly reduced, and the fire
is producing water vapor, carbon dioxide, perhaps a small quantity of sulfur
dioxide, carbon monoxide, and other gases.
Although the flame temperature may be well above 1,000° F., the temperature
in the room may only be slightly increased.
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The firefighter shall define the following stages of fire:
1. Incipient: Is the earliest phase of a fire beginning with the actual ignition.
2. Flame Spread:
the movement of flame away from an ignition source and into
adjacent areas and materials.
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The firefighter shall define the following stages of fire:
1. Incipient:
2. Flame Spread:
3. Hot Smoldering:
Is the earliest phase of a fire beginning with the actual ignition.
the movement of flame away from an ignition source and into
adjacent areas and materials.
combustion without flame, usually with incandescence
and smoke.
During the hot smoldering phase of a fire, flames may cease to exist if the area
of confinement is sufficiently airtight. Burning is reduced to glowing embers.
As flames die down, the room is completely filled with dense smoke and gases.
Air pressure may build to the point that smoke and gases are forced through
small cracks.
Total room temperatures in excess of 1,000° F. are possible. The intense heat
will have liberated most of the flammable gases, such as methane, from
combustible material in the room.
A backdraft hazard is produced. If no air is introduced, the fire will burn out
leaving totally incinerated contents.
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The firefighter shall define the following stages of fire:
1. Incipient: Is the earliest phase of a fire beginning with the actual ignition.
the movement of flame away from an ignition source and into
2. Flame Spread: adjacent areas and materials.
3. Hot Smoldering: combustion without flame, usually with incandescence
and smoke.
4. Flashover:
A transition phase in the development of a contained fire in which
surfaces exposed to thermal radiation reach ignition temperature
more or less simultaneously and fire spreads rapidly throughout the
space.
The cause is attributed to the buildup of heat from the fire itself. As the fire
continues to burn, all the contents of the room are gradually heated to their
ignition temperatures. When they reach their ignition point, simultaneous
ignition occurs, and the area becomes fully involved in fire.
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6. Clear and Free Burning:
The phase where sufficient oxygen and fuel are available
for fire growth and open burning to a point where total
involvement is possible.
Extinguishment of the fire at this stage requires application of water or other
agent to the seat of the fire. Water can be applied sparingly at the ceiling level
to cool the thermal layer and reduce flashover potential.
Too much water will produce excess steam, which can injure persons and
drive firefighters from the building.
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6. Clear and Free Burning:
The phase where sufficient oxygen and fuel are available
for fire growth and open burning to a point where total
involvement is possible.
7. Back Draft Explosion:
An explosion resulting from the sudden introduction of
air (oxygen) into a confined space containing oxygen
deficient superheated products of incomplete combustion.
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The firefighter shall identify two (2) chemical,
mechanical and electrical energy heat sources.
Chemical:
1. Heat of combustion (burning) - is the amount of heat
generated by combustion (oxidation reaction). The amount
of heat generated by burning materials will vary depending
on the material. Some materials are said to burn “hotter”
than others do.
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The firefighter shall identify two (2) chemical,
mechanical and electrical energy heat sources.
Chemical:
1. Heat of combustion
2. Spontaneous heating - is the heating of organic substance
without the addition of external heat. It occurs most
frequently where sufficient air is not present and insulation
prevents the dissipation of heat. This heat is produced by
low-grade chemical breakdown process. An example
would be oil-soaked rags that are rolled into a ball and
thrown into a corner. If there is not enough ventilation to
allow the heat produced to drift off, eventually the heat
will become sufficient to cause ignition of the rags.
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The firefighter shall identify two (2) chemical,
mechanical and electrical energy heat sources.
Chemical:
1. Heat of combustion
2. Spontaneous heating
Mechanical:
1. Heat of friction - is created by the movement of two
surfaces against each other. This movement results in
heat and/or sparks being generated.
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The firefighter shall identify two (2) chemical,
mechanical and electrical energy heat sources.
Chemical:
1. Heat of combustion
2. Spontaneous heating
Mechanical:
1. Heat of friction
2. Heat of compression - is generated when a gas is
compressed. Diesel engines ignite fuel vapor with out a
spark plug by the use of this principle. A gas cylinder
such as a SCUBA bottle feels warm to the touch after
filled with air.
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The firefighter shall identify two (2) chemical,
mechanical and electrical energy heat sources.
Chemical:
1. Heat of combustion
2. Spontaneous heating
Mechanical:
1. Heat of friction
2. Heat of compression
Electrical:
1. Resistance heating - refers to the heat generated by
passing an electrical current through a conductor such
as a wire or an appliance. Resistance heating is increased
if the wire is not large enough in diameter for the amount
of current carried. Fires can be caused when a standard
household extension cord is overloaded with to many
appliances plugged into it. Resistance heating can also be
increased if the conductor is tightly wound or coiled.
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The firefighter shall identify two (2) chemical,
mechanical and electrical energy heat sources.
Chemical:
1. Heat of combustion
2. Spontaneous heating
Mechanical:
1. Heat of friction
2. Heat of compression
Electrical:
1. Resistance heating
2. Heat from arcing - is a type of electrical heating that
occurs when the current flow is interrupted. Interruption
may be from an open switch of a loose connection. Arc
temperatures are extremely high and may even melt the
conductor. An example used in industrial applications
is a welder. The welding rod (conductor) melts away as
the metals melt and are joined together.
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The firefighter shall identify two (2) chemical,
mechanical and electrical energy heat sources.
Chemical:
1. Heat of combustion
2. Spontaneous heating
Mechanical:
1. Heat of friction
2. Heat of compression
Electrical:
1. Resistance heating
2. Heat from arcing
Another heat source which can be listed is:
Nuclear heat source:
Is generated when atoms are either split apart (fission)
or combined (fusion). In a controlled setting, fission is
used to heat water to drive steam turbines and produce
electricity. Currently fusion cannot be controlled and
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has no commercial use.
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Several of the natural laws of physics are involved in the transmission
of heat. The “Law of Heat Flow” specifies that heat tends to flow
from a hot substance to a cold substance. The colder of the two bodies
in contact will absorb heat until both objects are the same temperature.
Heat can travel through a building by one or more methods.
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Definition:
“Heat transfer to another body or within a body by direct heat”
Conduction is the form of heat transfer that takes place within solids when one
portion of an object is heated. Energy is transferred from the heated area to the
unheated area at a rate dependent on the difference in temperature and the
physical properties of the material.
Heat may be conducted from one body to another by direct contact or by an
intervening heat-conducting medium.
Liquids and gases are poor conductors of heat because of the movement of their
molecules, and air is a relatively poor conductor.
-- This is why double walls and storm windows that contain an air space
provide additional insulation from outside temperatures.
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Definition:
“Heat Transfer by circulation within a medium such as a gas or a liquid”
Convection is the transfer of heat energy by the movement of heated
liquids or gases from the source of heat to a cooler part of the
environment. Heat is transferred by convection to a solid when hot gases
pass over cooler surfaces. The rate of heat transfer to the solid is a
function of the temperature difference, the surface area exposed to the
hot gas, and the velocity of the hot gas. The higher the velocity of the
gas, the greater the rate of convective transfer.
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Definition:
“Heat transfer by way of electromagnetic energy”
Radiation is the transfer of heat energy from a hot surface to a cooler surface
by electromagnetic waves without an intervening medium. For example, the
heat energy from the sun is radiated to earth through the vacuum of space.
Radiant energy can be transferred only by line-of-sight and will be reduced or
blocked by intervening materials. Intervening materials do not necessarily
block all radiant heat. The rate of heat transfer is also strongly affected by the
distance between the radiator and the target. As the distance increases, the
amount of energy falling on a unit of area falls off in a manner that is related
to both the size of the radiating source and the distance to the target.
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The firefighter shall define the three (3) physical states of matter in
which fuels are commonly found.
1. Solids
2. Liquids
3. Gases
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Fuel may exist in any of the physical states of matter -- gas, liquid or solid. A solid is a
substance whose molecules, at ambient temperature, are held tightly in a fixed threedimensional relationship to one another by molecular forces. A solid has fixed volume
and shape. A liquid at ambient temperature has molecules held less tightly. A liquid has
a fixed volume but not a fixed three-dimensional shape. A gas at ambient temperature
has only weak bonds between it molecules and will expand to fill any available volume.
The state of fuel is directly related to temperature and pressure and can change as conditions
vary. At very high temperatures, solids may liquefy, and both solids and liquids will give off
vapors. At very high pressure, gases may become liquefied.
In order for solid and liquid materials to burn, these materials must be heated sufficiently to
produce vapors. It is the vapors that actually burn. The lowest temperature at which a solid
or liquid material produces sufficient vapors to burn under laboratory conditions is known as
the flash point. A few degrees above the flash point is the flame point, the temperature at
which the fuel will continue to produce sufficient vapors to sustain a continuous flame. The
temperature at which the vapors will ignite is the ignition temperature, also called the
autoignition temperature.
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Solid fuels have a definite shape and size that significantly affect the ignitability
of the fuel.
The primary consideration is the surface-to-mass ratio as this ratio of surface area
to mass increases; the fuel particles become more finely divided (sawdust as
opposed to logs).
As the surface area increases, heat transfer is easier and the material heats more
rapidly, thus speeding pyrolysis.
Fire spread is more rapid in a vertical direction than horizontally
Examples:
Wood
Coal
Flammable metals
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Liquid fuels have physical properties that increase the difficulty of
extinguishment and the hazard to personnel
A liquid will assume the shape of its container. When spilled, a liquid will
assume the flat shape of the ground, and it will flow and accumulate in low
spaces.
Examples:
Gasoline
Crude Oil
Alcohol
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Gases can be flammable if the molecules are combined with the proper amount
of air to support combustion.
The upper and lower flammable limits define the zone where a gas can burn.
Some gases like acetylene have such a low flammability limit that they can burn
in the presence of only a small amount of air.
Gases that are heavier than air, such as propane and ethane, will sink and
accumulate in low spaces.
Extra caution is needed to recognize hazardous area when working with gases.
Examples:
Methane
Hydrogen
Butane
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Fuel may be found in the three states of matter:
1. Solid
2. Liquid
3. Gas
The initiation of combustion of a liquid or solid fuel
requires their conversion into a gaseous state by
heating. Fuel gasses are evolved from solid fuels by
pyrolysis.
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Specific gravity is the measurement of the density
of liquids in relation to water. Liquids with a
specific gravity of less than one are lighter than
water. Those with a specific gravity greater than
one are heavier than water. Any liquid with a
specific gravity of one will mix evenly with water.
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Vapor density is the density of gas or vapor in
relation to air. If a gas has a vapor density less
than one (that of air), it will rise and dissipate
into open air. Gases with a vapor density greater
than one tend to settle, hug the ground, and travel
as directed by terrain and wind. All hydrocarbon
fuels with the exception of methane, have a vapor
density greater than one, and will hug the ground,
flow into low-lying areas where sources of ignition
may exist.
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Fuel to Mass Ratio is the ratio for the surface area
of the fuel to the mass of the fuel. As this ratio
increases, the fuel particles become smaller and
finely divided (coal dust as opposed to lumps of
coal) and the ignitability increases tremendously.
As the surface area increases, heat transfer is
easier and the material heats more rapidly, thus
speeding pyrolysis.
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When a material burns, it undergoes a chemical change.
None of the elements make up the material are destroyed
in the process, but all of the material is transformed into
another form or state.
--When a piece of paper burns the gases and moisture
contained within the paper are liberated. The
remaining solids take on the appearance of carbonized,
charred flakes.
--It was once thought that the weight of the by-products
of combustion would exactly equal the original weight
of the fuel. It is now known that a tiny amount of the fuel
is indeed converted into energy, so the by-products
weigh slightly less than the fuel did.
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The firefighter shall define the hazard of finely
divided fuels as they relate to the combustion
process:
Smoke most often is defined as the airborne solid and liquid
particulates and fire gases evolved when a material undergoes
pyrolysis or combustion. The fire gases have received the
most attention, while knowledge of the effects of inhalation
of particulates and aerosols from smoke is still quite limited.
Carbon monoxide (CO) is not the most toxic of fire gases, but it is the
most abundant and, therefore, is always the major threat in most fire
atmospheres. The toxicity of CO is primarily due to its affinity for
the hemoglobin in the blood, decreasing the capability of the blood
to transport oxygen throughout the body.
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The firefighter shall define the hazard of finely
divided fuels as they relate to the combustion
process:
Hydrogen cyanide (HCN) is produced from the burning of materials
that contain nitrogen. Natural and synthetic materials such as wool,
silk, nylon, polyurethanes, and urea-containing resins are included.
HCN is a rapidly acting toxicant which is 20 times more toxic than
CO. HCN inhibits the use of oxygen inside the cells.
Carbon dioxide (CO ) is usually evolved in large quantities from
fires. CO causes increased rate and depth of respiration, causing the
body to breath in more of the other fire toxicants and irritants. At a
10% concentration of CO , the breathing speed and depth may be
increased up to 8 to 10 times normal.
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The firefighter shall define the hazard of finely
divided fuels as they relate to the combustion
process:
Hydrogen chloride (HCI) is formed from the combustion of
chlorine-containing materials, the most notable of which is
polyvinyl chloride (PVC). It is a potent sensory and pulmonary
irritant. 75 PPM can cause eye irritation. Exposures of over
700 PPM for more than 30 minutes are highly dangerous. HCI can
combine with moisture in the lungs to form hydrochloric acid.
Nitrogen dioxide (NO ) and nitric oxide (NO) comprise a mixture
usually referred to as NO×. These nitrogen oxides result from the
oxidation of nitrogen-containing materials, with HCN also being a
source of NO× when it is burned at high temperatures. NO× has a
lethality comparable to HCN. It is most lethal in the lungs with
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death coming up to a day after a fatal exposure.
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THE FIREFIGHTER SHALL DEFINE:
FLASH POINT A solid or a liquid, if heated sufficiently, will give off a vapor
capable of ignition. The temperature at which the application of
flame will cause this vapor to ignite is termed the FLASH POINT.
The flash point is recorded as the temperature at which ignition
occurs to the vapor given off by the solid or liquid. It is the minimum
temperature which will ignite the vapor. It is not the temperature
which will sustain burning; that is the fire point.
FIRE POINT The FIRE POINT is defined as the lowest temperature at which
vapors are burning at the same rate that they are generated. At the
fire point, the temperature is high enough to support continuous
combustion. It will burn 10º to 50º F above the flash point.
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THE FIREFIGHTER SHALL DEFINE:
IGNITION TEMPERATURE Ignition or auto-ignition temperature is that temperature to which the
substance must be raised for vapors to ignite spontaneously without
the presence of an independent source of heat. The ignition temperature
is a function of degree of molecular activity of the vapor and is influenced
by the rate of air flow, rate of heating, size and shape of the material,
as well as the source of oxygen available for the chemical process to begin
and become self sustaining.
LOWER UPPER AND EXPLOSIVE LIMITS Flammable Limits: The upper or lower concentration limits at a specified
temperature and pressure of flammable gas or a vapor of an ignitable liquid
and air, expressed as percentage of fuel by volume that can be ignited.
Flammable Range: Concentration range of a flammable gas or vapor of a
flammable liquid in air that can be ignited.
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THE FIREFIGHTER SHALL DEFINE:
UPPER AND LOWER EXPLOSIVE LIMITS (cont.)Explosive Limits: Most of us are familiar with the phenomenon of being
unable to start a car because the carburetor was flooded, resulting in too
rich a mixture (of gasoline and air), or the carburetor being out of
adjustment, resulting in to lean a mixture.
This phenomenon indicates that the carburetor was supplying fuel to the
car either above or below the flammable or explosive limits of the gas.
Practically all flammable gases or liquids which can be vaporized have
limits beyond which the mixture will not burn. These are called the
explosive or flammable limits. The range between the upper and lower
limits is called the explosive or flammable range of the substance.
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The Firefighter shall define concentrations of
oxygen in air as it affects combustion
In most fire situations, the oxidizing agent is the oxygen
in the earth’s atmosphere. Fires can occur in the absence
of atmospheric oxygen, when fuels are mixed with chemical
oxidizers. Many chemical oxidizers contain readily
released oxygen. Ammonium nitrate fertilizer, potassium
nitrate and hydrogen peroxide are examples.
Air contains approximately 21% oxygen. With out an air supply, insufficient
oxygen often results during combustion. Flaming combustion usually ceases
when the available oxygen is less that 16 %.
While not a true gas, occurs when the fire consumes available
oxygen in an area. Oxygen concentrations less than 17% can
cause impairment of motor skills. 14% to 10% may cause
fatigue and faulty judgement. 10% to 6% will cause
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unconsciousness and impending death.
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The Firefighter shall identify three
products of combustion commonly
found in structural fire which create
a fire hazard.
Four categories of combustion byproducts are produced as the
result of combustion:
1. Gases
Fire gases produced in most fires depend on certain variables, including the chemical
makeup of the burning materials, the available oxygen during burning, and/or
the temperature of the fire and the fire area.
The toxicity of these gases is determined by variables such as the concentration
(percent) of gas in the air, the length of exposure, and the physical condition of
the victim.
The toxic effects on personnel are greater during the fire because of increased
respiration by the victim from exertion, heat and excess carbon dioxide. What
ordinarily appear to be harmless amounts of toxic by products may become
dangerous during the fire.
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The Firefighter shall identify three
products of combustion commonly
found in structural fire which create
a fire hazard.
Four categories of combustion byproducts are produced as the result of
combustion:
1. Gases
2. Flame
Flame results from the burning of most materials in an oxygen-rich atmosphere.
This produces luminosity (flame). Therefore, flame is considered to be a
“byproduct” of combustion.
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The Firefighter shall identify three
products of combustion commonly
found in structural fire which
create a fire hazard.
Four categories of combustion byproducts are produced as the result of
combustion:
1. Gases
2. Flame
3. Heat
Heat is commonly defined in terms of intensity of heating rate (Btu/sec or kilowatts)
or as the total heat energy received over time (Btu). In a fire, heat produces fuel
vapors, cause ignition, and promotes fire growth and flame spread by maintaining a
continuous cycle of fuel production and ignition. The presence of moisture in
heated air increases the danger and the damage.
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The Firefighter shall identify three
products of combustion commonly
found in structural fire which create a
fire hazard.
Four categories of combustion byproducts are produced as the result of
combustion:
1. Gases
2. Flame
3. Heat
4. Smoke
Smoke consists of very fine solid particles and condensed vapor. Gases that are
produced by the heating of combustible materials are contained in flammable tar
droplets and carried upward within the thermal column. Very little smoke is
produced during complete combustion. As combustion diminishes, smoke density
increases.
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The Firefighter shall identify
characteristics of water as it relates to its
fire extinguishing potential.
Water has the ability to extinguish fire in
several ways. The primary way is by cooling.
It may also be used to smother a fire, excluding
oxygen.
Water exits in a liquid state between 32º F. and 212º F.
Below 32º F. it turns to ice and above 212º F. it turns to
steam. When steam cools and converts back to water it
is know as condensed steam. It ranges from 60 lb/ft³ at
freezing and 60 lb/ft³ close to boiling. Each pound of
water requires approximately 970 Btu’s of additional
heat to completely turn into steam. When water is
converted to steam, it expands 1700 times it original
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volume.
The Firefighter shall identify characteristics of
water as it relates to its fire extinguishing
potential.
The large heat of vaporization is another reason for the effectiveness of
water as an extinguishing agent. The heat absorbed by the water is
subtracted from the burning system so it cannot be used for vaporizing
more liquid or pyrolyzing more solid fuel. A relatively large amount of
heat is required to change water into steam. The greater the surface area
of the water absorbed, the more rapidly heat will be absorbed.
Disadvantages of water include it weight ( 8+ pounds per gallon), it is
conductor of electricity, and use of water can spread light than water fuel
fires. The conversion of water into steam accompanied by rapid expansion
can burn firefighters or trapped victims.
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Basic Fire Behavior End Note:


Personal Size-UP
Always make a
continuous mental
evaluation of your
immediate
environment, facts,
and probabilities to
come home safe,
and Good Luck!!!!
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Intermediate Principles of:
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a)
b)
c)
d)
e)
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2.1 The firefighter shall define the
following units of measure:
British Thermal Units (BTU)
Fahrenheit (F)
Celsius (C)
Calorie (C)
Joule, the SI unit of energy
2.2 The firefighter shall define
thermal balance and imbalance.
Intermediate Objectives
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A) British Thermal Unit is a unit of energy, 1876–
present, usually referred to as a Btu (pronounced
“bee tee u”).
 Originally defined as the quantity of heat needed
to raise the temperature of 1 pound avoirdupois
of air-free water 1°F under a constant pressure
of 1 atmosphere, starting at the temperature at
which water is most dense, 39.1°F. This is about
the amount of energy released when the tip of a
kitchen match burns.
 Since the calorie, another measure of a quantity
of heat, is also defined in terms of a temperature
interval and the mass of water heated, any
definition of a calorie implies a definition of a
Btu.
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Define: British Thermal Unit
(BTU)
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Define: British Thermal
Unit (BTU)
Name of unit
Symbol Equivalent in joules
International Table Btu. Based on the
definition of the International Table
calorie (exactly 4.1868 J) at the Fifth
International Conference on the
Properties of Steam (London, July 1956).
BtuIT
exactly 1055.055 852 62
joules
thermo chemical Btu. Based on the
Btuth
definition of the thermo chemical calorie
(exactly 4.1840 joules) by the U.S. Bureau
of Standards in 1953.
approximately 1054.350
joules
mean Btu. 1⁄180 of the quantity of heat
needed to raise the pound of water from
32° F to 212° F
1055.87 joules
39°F Btu
1059.67 joules
59°F Btu
1054.80 joules
60°F Btu
1054.68 joules
86
B) Fahrenheit
Pronunciation: 'far-&n-"hIt, 'ferDaniel G. Fahrenheit
 Relating or conforming to a thermometric
scale on which under standard
atmospheric pressure the boiling point of
water is at 212 degrees above the zero of
the scale, the freezing point is at 32
degrees above zero, and the zero point
approximates the temperature produced
by mixing equal quantities by weight of
snow and common salt -- abbreviation F

Define: Fahrenheit
87
C) Celsius
Pronunciation: 'sel-sE-&s, -sh&s
 Relating to, conforming to, or having the
international thermometric scale on which
the interval between the triple point of
water and the boiling point of water is
divided into 99.99 degrees with 0.01°
representing the triple point and 100° the
boiling point <10° Celsius> -abbreviation C

Define: Celsius
88
D) calorie
Variant(s): also cal·o·ry /'ka-l&-rE, 'kal-rE/
Etymology: French calorie, from Latin calor heat,
from calEre to be warm
 1 a : the amount of heat required at a pressure
of one atmosphere to raise the temperature of
one gram of water one degree Celsius that is
equal to about 4.19 joules -- called also gram
calorie, small calorie; abbreviation cal b : the
amount of heat required to raise the temperature
of one kilogram of water one degree Celsius :
1000 gram calories or 3.968 Btu -- called also
large calorie; abbreviation Cal
 2 a : a unit equivalent to the large calorie
expressing heat-producing or energy-producing
value in food when oxidized in the body b : an
amount of Calorie
food having an energy-producing
Define:
value of one large calorie

89


E) The unit of energy in SI. Symbol, J. The work
done when the point of application of a force of 1
newton is displaced 1 meter in the direction of the
force. One watt-second is equal to 1 joule.
The joule’s dimensions are force × length (newton
× meter, or in terms of base units only:) meter² x
kiligram
seconds²
 The joule is named after James Prescott Joule
(1818 – 1889), who in 1845 was the first to
measure the equivalence of work and heat, by
having falling weights rotate paddles in water.
 The joule was adopted in 1889 by the International
Electrical Congress. When the CGPM first defined
SI, in 1960, it included the joule as one of the
derived units.
Define:
Joule
90
When combustion occurs, heat is liberated
as part of the oxidation process.
 The properties of molecules are such that
as heat is applied or absorbed, the
molecular makeup becomes agitated.
 Simply, that means the outermost
boundary of the molecular collection will
push outwardly and expand.

Define: Thermal Balance and
Imbalance
91
Looking at the anatomy of heat given off
by a fire, one can visualize the lighter
heated air moving upwardly and the
cooler air dropping to lower levels.
 Firefighters knowing these significant
characteristics by how and why heat
moves will enable the firefighter to
employ tactics that will limit extension,
confine the fire, and extinguish it.

Define: Thermal Balance and
Imbalance
92
Hot air rises from a fire and will continue
to rise until it reaches equilibrium with its
surrounding atmosphere.
 When confined to a structure, the hotter
air will accumulate on the ceiling of the
room and Bank Down until it can find an
escape route.
 Sometimes it will bank down right to the
floor.

Define: Thermal Balance and
Imbalance
93
Watching the smoke from a fire will give
us an indicator as to what is happing with
the heated air.
 Because the unburned particles of fuel
found in smoke are affected by hot air,
tracking the smoke will expose the path
taken by the hot air.

Define: Thermal Balance and
Imbalance
94
It is the physical characteristics of thermal
balance and imbalance that cause smoke
to column and mushroom.
 The heated air and smoke rise.
 The hotter the air, the faster and more
violent the ascent.
 When the thermal balance of the air has
been reached, the ascent ceases and
establishes equilibrium with the
surrounding
atmosphere.
Define:
Thermal
Balance and

Imbalance
95
The smoke then Stratifies and begins to
move horizontally in all directions from
the central thermal column.
 The result is a form that looks like a
mushroom.
 However, in a structure, the mushrooming
of smoke and heat occur for different
reasons.

Define: Thermal Balance and
Imbalance
96
In a structure, the heated air meets an
obstruction in the ceiling and, being
unable to rise further, spreads out
horizontally seeking another vertical exit.
 If unable to find that exit, it banks down
and compresses the volume of air in the
structure.

Define: Thermal Balance and
Imbalance
97

This compression causes air pressure
within the confined structure, and any
opening will show smoke and possibly fire
being violently expelled with such force
that it causes the smoke to roll and billow.
Define: Thermal Balance and
Imbalance
98
Inter. Fire Behavior End Note:


Personal Size-UP
Always make a
continuous mental
evaluation of your
immediate
environment, facts,
and probabilities to
come home safe,
and Good Luck!!!!
99
Advanced Principles of:
100
3.1 The firefighter shall identify chemical
by-products of combustion.
 3.2 The firefighter shall define diffusion
flame process.
 3.3 The firefighter shall define the fire
extinguishment theory.
 3.4 The firefighter shall identify pressure
and velocity.

Advanced Objectives
101
102

Diffusion: A natural occurring event in
which molecules travel from levels of high
concentration to areas of low
concentration.
Define: Diffusion Flame
Process
103
The way to stop a fire is to remove one its
essential ingredients.
 Knowing that for self-sustaining chemical
reaction we call combustion to occur, four
elements are needed:
 Heat
 Fuel
 Oxygen
 Chemical reaction
Define:
Extinguishment
 Remove one
of them and the fireTheory
collapse.

104

More formally stated, we can say that
Temperature diminution, Fuel elimination,
Oxygen elimination, or Chemical flame
repression will extinguish fire.
Define: Extinguishment Theory
105
106
Pressure: The force, or weight, of a
substance, usually water, measured over
an area.
 Velocity: The forward pressure as it leaves
an opening.

Identify: Pressure and Velocity
107