Newfoundland and Labrador Association of Fire Chiefs and Firefighters

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Newfoundland and Labrador Association of Fire
Chiefs and Firefighters
Founded 1964
Incorporated 1979
Serving Our Province for the Betterment of Fire
protection
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NLAFCFF. Basic Firefighting Course

• Fire Behaviour
• Lesson One

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OverviewIn this lesson, you will look at

• Ways to measure
• Heat and temperature.
• Combustion.
• Fire extinguishment theory.
• Classification of fires.

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ObjectivesBy end of this lesson, you should be
able to

• 1.1 Identify the correct measurement system for
  measuring length, mass, time, temperature,
  electric current, amount of substance, weight,
  force, energy, work, power, and luminous
  intensity.
• 1.2 Identify the method for transferring heat and
  their characteristics.
• 1.3 Identify and state the Law of Conservation of
  Mass-Energy.
• 1.4 Identify the components of the fire
  tetrahedron and their characteristics.
• 1.5 Identify the ways that fire develops and
  their characteristics.
• 1.6 Identify thermal layering of gases and how it
  effects fire growth.
• 1.7 Identify backdraft and conditions that cause
  it.
• 1.8 Identify the products of combustion.
• 1.9 Identify ways to extinguishing fire.
• 1.10 identify the classes of fire and their
  characteristics.

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• Measurement System
• English or Customary System
• International System of Units or SI

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• Energy
• Is simply defined as the capacity to perform work

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• Work
• Is the transformation of energy from one form to
  another.
• The SI unit for work is joule (j)

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• Many types of Energy
• Chemical Energy released as a result of a
  chemical reaction such as combustion
• Mechanical Energy an object in motion possesses
  such as a rock rolling down hill.
• Electrical Energy developed when electrons flows
  through a conductor.
• Heat Energy transferred between two bodies of
  differing temperature such as the sun and earth

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• Light Visible radiation produced at the atomic
  level such as a flame produced during the
  combustion reaction.
• Nuclear Energy released when atoms are split or
  join together.

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Energy exist in two stages

• Potential energy is the energy possessed by an
  object that can be released in the future.

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Kinetic energy

• is the energy possessed by a moving object

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Power

• Is the amount of energy delivered over a given
  period of time.

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Heat and Temperature

• Heat Is the energy transferred from one body to
  another when the temperature of the bodies are
  different.
• Temperature Is an indicator of heat and is the
  measure of warmth or coldness of an object based
  on some standard.

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• Transfer of heat from body to body is measured as
  energy flow (heat) over time.
• This is can be described as Btu/s or kilowatts
  (kW)

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Methods of Transferring Heat
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• Conduction Point to Point. Energy is transfer
  from heated area to unheated area

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• Convection Transfer of heat from movement of
  heated liquid or gases.

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• Radiation Transmission of energy as
  electromagnetic waves without an intervening
  medium.

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Matter
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• Matter can be described by its physical
  properties such as mass, size or volume.
• Matter can also be described in terms of density.
• Specific gravity is the ratio of mass of a given
  volume of a liquid compared with the mass of an
  equal volume of water.
• Vapour density is the density of gas vapours in
  relation to air.

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Law of Conservation of Mass-Energy

• Mass and energy can be converted from one to
  another but there is never any net loss of total
  mass-energy. The reduction in mass of a fuel
  results in the release of energy in the form of
  heat and light.
• Fuel Heat Extinguishing Agent

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• Chemical reaction refers to matter changing from
  one form to another or producing a new substance
  (Water ice New substance hydrogen oxygen
  water)

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• These changes involve an exchange of energy.

• Reactions that give off energy are called
  exothermic.
• Heat and light are exothermic
• Oxidation (exothermic reaction) is the formation
  of a chemical bond between oxygen and another
  element (oxygen iron rust.
• Reactions that absorb energy are called
  endothermic ( water changing to steam

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COMBUSTION
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Combustion is defined as a self-sustaining
chemical reaction yielding energy or products
that causes further reactions.
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Fire Tetrahedron

• Oxidizing agent
• Fuel
• Forms of Heat (Chemical Electrical Mechanical
  Nuclear)
• Self-sustained chemical reaction

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Oxidizing Agent
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• Air consists of 21 oxygen.
• Combustion is supported at oxygen concentrations
  as low as 14, but can be supported at lower
  concentration in high temperatures.

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Common Oxidizers

• Bromates
• Bromine
• Chlorates
• Chlorine
• Fluorine
• Nitrates
• Nitric acid
• Perchlorates
• Permanganates
• Peroxides

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Fuel
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Heat
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Chemical Reaction
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Fire Development

• Stages of compartment fire
• Ignition
• Growth
• Flashover
• Fully developed
• Decay

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Ignition

• Ignition describes the period when the four
  elements of the fire tetrahedron comes together
  and combustion begins.

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Growth

• Shortly after ignition, a fire plume begins to
  form above the burning fuel. As the plume
  develops, it begins to draw or entrain air from
  the surrounding space into the column

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Flashover

• Flashover is the transition between the growth
  and the fully developed fire stages and is not a
  specific event such as ignition

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Fully Developed

• The fully developed fire stage occurs when all
  combustible materials in the compartment are
  involved in fire. During this period of time, the
  burning fuels in the compartment are releasing
  the maximum amount of heat possible for the
  available fuel packages and producing large
  volume of fire gases.

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Decay

• As the fire consumes the available fuel in the
  compartment, the rate of heat release begins to
  decline. Once again the fire becomes fuel
  controlled, the amount of fire dimishes, and the
  temperatures within the compartment begins to
  decline.

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Fire development is affected by the following
factors

• Size, number and arrangements of ventilation
  openings
• Volume of compartment
• Thermal properties of the compartment enclosures
• Compartment ceiling height
• Fuel

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Flameover/Rollover

• Conditions where flames move through or across
  the unburned gases during a fires progression
• Flameover involves only the fire gases.

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Thermal layering/heat stratification/thermal
balance

• Thermal layering of gases is the tendency of
  gases to form into layers according to
  temperature.
• A thermal imbalance can be created if water is
  applied to the upper level of the thermal layer
  or if continuous water is applied after the fire
  has been down.

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Backdraft

• Occurs when air is mixed in large volume of hot,
  unburned fire gases collected in an unventilated
  space.

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Potential backdraft conditions

• Pressurized smoke exiting small opening.
• Black smoke becoming gray-yellow
• Confined and excessive heat
• Little or no visible flame
• Smoke leaving building in puffs
• Smoke stained windows.

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Extinguishing a Fire

• Temperature reduction

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• Cooling with water reduces the temperature.
  However it does not sufficiently reduce vapour
  production of low flash point substances

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Fuel Removal
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Chemical flame inhibition
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• Dry chemical and halons stop flaming and are
  effective on gas and liquid fires
• A substances solubility affects extinguishment.
• Most ignitable liquids have a specific gravity of
  less than 1 and can float on water to burn.
• Polar solvent-dissolves in water ie rum and
  water
• Non polar will not dissolve in water ie gas and
  water.
• Vapour density also affects extinguishment.
  Vapours less than 1 rises, greater than 1 sinks.

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Oxygen exclusion
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• Carbon dioxide or foam can be used on fuels that
  are not self-oxidizing..
• Placing a cover over a pan of burning food.

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How do we Classify Fires
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Class A

• Ordinary combustibles

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Class B

• Flammable and combustible liquids and gases

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Class C

• Energized electrical equipment

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Class D

• Combustible metals

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Test

• 1. The phase of fire characterized by full fire
  involvement and a release of the maximum amount
  of heat possible for the available fuel.
• A. Ignition
• B. Decay
• C. Fully developed
• D. Backdraft
• 2. The transfer of heat by the movement of heated
  liquids or gases is known as
• A. Conduction
• B. Convection
• C. Radiation
• D. Mechanical

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• 3. Heat can be transferred from one body to
  another by the following three methods
• A. Conduction, flashover, chemical reaction
• B. Conduction, flameover, flashover
• C. Conduction, extension, radiation
• D. Conduction, convection, radiation
• 4. Water extinguishes fire basically
• A. Removing the fuel source
• B. Reducing the temperature
• C. Reducing the oxygen supply
• D. Interrupting the chemical chain reaction

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• 5. is the tendency of gases to form into
  layers according to temperature.
• A. Thermal layering
• B. Pyrolysis
• C. Vapourization
• D. Chain reaction
• 6.The amount of heat required to raised the
  temperature of 1 gram of water 1 degree Celsius.
• A. Calorie
• B. Btu
• C. Potential energy
• D. Kinetic energy

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• 7. The following are common oxidizers.
• A. Oxygen, chlorine, nitric acid
• B. Oxygen, gasoline, alcohol
• C. Oxygen, chlorine, propane
• D. Gasoline, kerosene, chlorine
• 8. Fire that occurs in a higher than normal
  concentration of oxygen will
• A. Burn at the same rate
• B. Burn at a slower rate than normal
• C. Burn at a faster rate than normal
• D. Self-extinguish

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• 9. To burn, fuel must normally be in the
• A. Solid state
• B. Liquid state
• C. Gaseous state
• D. Chemical
• 10. As a fire burns it produces these products of
  combustion
• A. Thermal layering, smoke, heat
• B. Smoke, heat, oxygen, carbon
• C. Smoke, heat, oxygen, light
• D. Smoke, heat light, fire gases

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• 11. Which product of combustion will cause burns
  and damage to the respiratory tract?
• A. Light
• B. Heat
• C. Smoke
• D. Fire gases
• 12. What two factors influence the combustion
  process?
• A. Distribution of the fuel and reducing agent
• B. Physical state and distribution of the fuel
• C. Physical state and volume of the fuel
• D. Chemical chain reaction and volume of the
  fuel.

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Answers to test

• 1. The phase of fire characterized by full fire
  involvement and a release of the maximum amount
  of heat possible for the available fuel.
• A. Ignition
• B. Decay
• C. Fully developed
• D. Backdraft
• 2. The transfer of heat by the movement of heated
  liquids or gases is known as
• A. Conduction
• B. Convection
• C. Radiation
• D. Mechanical

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• 3. Heat can be transferred from one body to
  another by the following three methods
• A. Conduction, flashover, chemical reaction
• B. Conduction, flameover, flashover
• C. Conduction, extension, radiation
• D. Conduction, convection, radiation
• 4. Water extinguishes fire basically
• A. Removing the fuel source
• B. Reducing the temperature
• C. Reducing the oxygen supply
• D. Interrupting the chemical chain reaction

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• 5. is the tendency of gases to form into
  layers according to temperature.
• A. Thermal layering
• B. Pyrolysis
• C. Vapourization
• D. Chain reaction
• 6.The amount of heat required to raised the
  temperature of 1 gram of water 1 degree Celsius.
• A. Calorie
• B. Btu
• C. Potential energy
• D. Kinetic energy

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• 7. The following are common oxidizers.
• A. Oxygen, chlorine, nitric acid
• B. Oxygen, gasoline, alcohol
• C. Oxygen, chlorine, propane
• D. Gasoline, kerosene, chlorine
• 8. Fire that occurs in a higher than normal
  concentration of oxygen will
• A. Burn at the same rate
• B. Burn at a slower rate than normal
• C. Burn at a faster rate than normal
• D. Self-extinguish

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• 9. To burn, fuel must normally be in the
• A. Solid state
• B. Liquid state
• C. Gaseous state
• D. Chemical
• 10. As a fire burns it produces these products of
  combustion
• A. Thermal layering, smoke, heat
• B. Smoke, heat, oxygen, carbon
• C. Smoke, heat, oxygen, light
• D. Smoke, heat light, fire gases

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• 11. Which product of combustion will cause burns
  and damage to the respiratory tract?
• A. Light
• B. Heat
• C. Smoke
• D. Fire gases
• 12. What two factors influence the combustion
  process?
• A. Distribution of the fuel and reducing agent
• B. Physical state and distribution of the fuel
• C. Physical state and volume of the fuel
• D. Chemical chain reaction and volume of the
  fuel.