Download SAMPLE LESSON PLAN

DATE: 2009-09-04
INSTRUCTOR: Bob Kissner
SUBJECT: Fire Behaviour
TOTAL TIME: 3 hours.
-------------------------------------------------------------------------------------------LEARNING OUTCOMES
Upon completion of this lesson, the learner will be able to:
1. Define the terms “combustion” and “spontaneous combustion”.
2. List the elements of the fire triangle and the fire tetrahedron and
their relationship to one another.
3. Describe the effects of heat on solid, liquid and gaseous fuels.
4. Define the following terms:
 Flash point.
 Fire point.
 Auto ignition temperature.
 Flashover.
 Backdraft.
 Rollover.
 Pyrolysis.
 B.L.E.V.E.
 Specific Gravity.
 Vapour Density.
 Upper Explosive Limit/Lower Explosive Limit.
5. Define and describe the stages of fire growth.
6. Define and describe the four methods of heat transfer.
7. Describe the products of combustion.
8. Identify the four classes of fire give two examples of fuels in each
class.
9. Describe common fire extinguishing agents.
10. Describe the extinguishing agents appropriate to each class of
fire along with the advantages/disadvantages of each.
11. Describe the four attributes of “reading smoke” and their
application in determining fire stage and growth.
--------------------------------------------------------------------------------------------
INTRODUCTION
Every topic covered in the Pre Service Fire Program can be hinged
on the firefighter’s knowledge of fire behaviour and chemistry. A
thorough knowledge of this material will, in fact, be a necessary tool
to ensure firefighter life safety. (Describe the concept of a fire
burning in a structure to that of a fire in a box). If we do not know
what is happening in the box and how the box will be affected, we are
at risk of being in danger due to the fire or the collapse of the box.
Describe the changes that have affected firefighting in the past
several decades:
 The “box” is often made of lightweight construction.
 The “box” is often filled with materials which produce much
greater amounts of energy than in the past (p. 103 of 5th
ed.)
 We are sending firefighters into the “box” in a completely
protective covering (making it more difficult to discern
changing conditions).
 We have seen a decrease in the number of structure fires.
(Show backdraft video clip from 5th edition DVD).
-------------------------------------------------------------------------------------------PRESENTATION:
Lesson Outline:
1. Introduce the concept of the fire triangle.
 Oxygen, heat and fuel.
 Fuel:
i. Matter-anything that takes up
space.
ii. Composed of
atoms/molecules.
iii. Known as the reducing agent
which combines with oxygen.
 Oxygen:
i. Elemental gas.
ii. Consists of 2 atom molecule.
iii. Chemical formula 02.
BBD or Flip Ch.
PPT 3-10
PPT 3-27
PPT 3-36 to 3-39
iv. Oxidizing agent which
combines with reducing agent.
v. May be substance other than
just oxygen.
vi. Air is normally 21% oxygen.
vii. Combustion is not supported
below 14% but this amount
can be lowered by high temps.
viii. O2 rich atmospheres can
cause normally non
combustibles to burn.
 Heat:
i. Form of energy.
ii. Describe difference between
heat and temperature.
iii. Describe the forms of heat
energy and sources of each:
1. Chemical
2. Electrical
3. Mechanical
4. Nuclear
5. Solar
iv. Describe spontaneous heating
or combustion-chemical and
biological (see textbook).
v. Describe methods of heat
transfer:
1. Conduction.
2. Convection.
3. Radiation
2. Explain the effects of heat on matter:
 Solids:
i. Atoms cannot move vertically
or horizontally-constant shape
and volume.
ii. Heat causes vibration which
will result in expansion and
contraction.
p. 104 of 5th ed.
Table 3-7
PPT 3-12 to 3-19
p. 91-93 of 5th
ed.
PPT 3-20 to 3-25
p. 94-95 of 5th
ed.
BBD or Flip ch.
p. 90 of 5th ed.
p. 98 of 5th ed.
 Liquids:
i. Continued heating of solids will
cause them to turn to liquidsmolecules slide around and
across each other.
ii. Known as fusion or melting.
iii. Constant volume but takes
shape of container.
iv. Define the following terms
related to liquids:
1. specific gravity.
2. flash point.
3. fire point.
4. auto ignition point.
5. See Table 3.4 on p. 99 of
5th edition.
 Gases:
i. Continued heating causes
molecules to lose ordinary
arrangement.
ii. Take shape and volume of
container.
iii. Define the following terms
related to gases:
1. Vapour density.
2. Upper and lower
explosive limits and
flammable range.
iv. Define B.L.E.V.E. (p. 774 of 5th
ed.) and show sample video.
 Use a chart on the BBD to outline
fusion, vapourization, condensation,
sublimation, freezing. Explain that
the change of a solid to a gas in fire
situations is know as “pyrolysis”.
 Describe the production of “free
radicals”:
i. Additional heating causes a
chemical change rather than a
p. 98 of 5th ed.
p. 98 of 5th ed.
p. 105 of 5th ed.
OAFC Bleve
video.
BBD or Flip ch.
p. 90 of 5th ed.
PPT 3-11
BBD or Flip ch.
p. 114 of 5th ed.
BBD or Flip ch.
physical one. Molecules
PPT 3-55 to 3-70
actually break down and
combine with other molecules
(oxygen being one of the most
abundant) to make new
compounds-byproduct of this
process is the production of
heat which now causes a chain
reaction to occur. The process
has now become exothermic
(producing its own heat) rather
than endothermic (requiring an
external source of heat).
 Explain the need for a fourth sidechemical chain reaction.
3. Define “combustion”: An exothermic
chemical reaction that is a self sustaining Show sample
videos.
process of rapid oxidation of a fuel that
produces heat and light. Discuss speed at
which oxidation reactions can occur:
 Slow-rusting.
 Rapid-combustion.
 Instantaneous-explosion (eg.
sawdust or grain).
4. Describe stages of fire development:
 Incipient:
i. 4 sides of tet come together
and fire ignites-can be piloted
or unpiloted.
ii. Fire is small and confined.
iii. Plume of hot gases and flame
reaches ceiling and starts
mushroom horizontally.
iv. Space is habitable at this
stage.
v. See Table 3.10 on p. 114 of 5th
ed.
 Growth:
i. Fire is now influencing the
environment in the
compartment.
ii. Plume of air in entrained into
the room and thermal layering
begins to occur.
iii. Smoke begins to exit from
upper area of openings and air
enters the lower area.
iv. This stage ends with:
1. isolated flames.
2. rollover.
3. flashover:
a. describe signs of
impending
flashover (p.119 of
5th ed.)
b. describe
procedures to
follow if indicators
are observed.
 Fully Developed:
i. Stage when energy released is
at its maximum and is limited
only by fuel or oxygen.
ii. Fire is vent controlled in that
energy released depends on
size and number of
compartment openings.
 Decay Stage:
i. Fuels or oxygen will not
support flaming combustion.
ii. If the fire is fuel controlled and
not vent controlled, the heat
release rate will drop but
products of combustion can
still accumulate in the hot
Show sample
videos.
p. 109 of 5th ed.
PPT 3-44 to 3-45
Dodson DVD.
Sample Videos.
compartment and ignite-a
smoke explosion.
iii. If fire is vent controlled, the
lack of oxygen will not support
flaming combustion. The
amount of heat will still enable
flammable products of
combustion to be produced.
The introduction of oxygen at
this stage results in a
backdraft. Describe the signs
of potential backdraft:
1. pressurized smoke
exiting small openings.
2. black smoke becoming
gray-yellow.
3. confinement with high
heat.
4. little or no flame.
5. puffing (breathing
smoke).
6. high smoke volume.
7. smoke stained windows.
p. 130-132 of 5th
ed.
BBD or Flip Ch.
PPT 3-70 to 3-84
5. Outline the various products of
combustion-have class “brainstorm” what
a fire produces. Include the following in
particular.
 Particulates will be covered with
condensed toxins as gases cool.
 The dangers of carbon monoxide.
 The chart on p. 109 of 5th ed.
BBD or Flip Ch.
6. Explain the concept of “reading smoke”
PPT 3-48 to 3-54
 Smoke is a fuel. It is not burning
because it is not hot enough or there
is not enough oxygen.
 Smoke is an indicator of what the fire
is doing and what it may do.
 Smoke reading can be affected by
outside temperature, size of the box,
material which is burning.
 Rate of change is a very important
factor to consider.
 The four attributes of smoke reading;
i. Density: Describes quality of
burning. Dense smoke
indicates an oxygen deficient
fire or a fire nearing ignition
temperature.
ii. Colour: May indicate material
which is burning. White is
early stage but may indicate a KFD power point
serious fire in a large structure CD on Building
Construction.
(become white as it travels
long distances). Brown may
indicate structure itself is
involved (review dangers of
lightweight construction).
Black may indicate late stage
fire or involvement of
hydrocarbons.
iii. Volume: May indicate amount
of material burning but is
affected by the size of the
container.
iv. Velocity: A measure of how
hot the smoke is. Discuss
concept of black fire-dense
smoke with high velocity which
indicates it is near ignition
temperature.
 Show the Dodson DVD “The Art of
Reading Smoke”. Then show other
video samples.
7. Discuss the methods of extinguishment
using pages 130-132 of the 5th edition.
 Temperature reduction:
i. Water.
ii. Foam.
 Fuel Removal:
i. Foam.
ii. Shutting of a gas valve.
iii. Dry chemicals.
 Oxygen Exclusion:
i. CO2.
ii. Foam.
iii. Lid on a pan.
iv. Dry powder (Class D)
 Chemical Flame Inhibition:
i. Dry chemical.
ii. Dry powder.
8. Use a chart to describe the classes of fire,
giving and example of each and examples
of suitable extinguishing agents.
 A-normal combustibles (wood,
paper) extinguished by water, foam,
multi-purpose dry chemical.
 B-flammable liquids (gasoline, oil,
diesel) extinguished by CO2, dry
chemical or foam.
 C-energized electrical equipment
extinguished by CO2, dry chemical
or (once de-energized) by water.
 D-combustible metals (magnesium,
aluminum) extinguished by dry
powder specific to the metal.
 K-combustible cooking oils and
greases extinguished by a Class K
extinguishing agent.
SUMMARY
We have defined fire scientifically, discussed the products produced
when a fire occurs, explained the stages a fire goes through,
classified fire into groups, described the various extinguishing agents
that are available, learned the importance of reading smoke and
building construction in order to remain safe and looked at how we
can make buildings safer. It is hoped that this lesson will enable you
to better understand what is actually occurring when a fire takes
place in order to be as safe as possible.
-------------------------------------------------------------------------------------------APPLICATION AND TEST
1. Define the term “combustion”.
2. What are the four sides of the fire tetrahedron.
3. Define the following terms;
 Flash point.
 Fire point.
 Lower explosive limit.
 B.L.E.V.E.
 Flashover.
 Backdraft.
4. Name and describe the stages of fire growth in a compartment.
5. What is convection?
6. Describe one toxic product of combustion and explain its hazards.
7. Describe and name an extinguishing agent for each of the classes
of fire.
8. Name the four attributes used to read smoke and describe what
each indicates.
ASSIGNMENT
This topic can be related to all of the other topics in this course. Keep
in mind the concepts that have been covered in order to better
understand the additional material you will be presented with.
-------------------------------------------------------------------------------------------REFERENCES:
TRAINING AIDS:
Essentials of Firefighting 5th ed.
Ontario Standardized Curriculum
Overhead projector.
Computer and LCD.
for Firefighters-Module 2.
Blackboard or flipchart.
Essentials of Firefighting 5th
Ed. CD
Essentials of Firefighting 5th
Ed. Power Point Ch. 3
KFD sample videos for
Flashover/backdraft.
OAFC B.L.E.V.E. video.
Dodson “The Art of Reading
Smoke” DVD.
KFD building construction
Power point.