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Flashcards in 3 Fire Behavior Deck (153):
1

The science of fire is an attempt to understand and control fire and involves both scientific and commonsense answers to the following questions

How does fire transform matter. How does fire spread

2

When material burns a visible change occurs, generating what

Heat and light

3

What occurs when a material or substance remains chemically the same but changes in size shape or appearance

A physical change

4

What occurs when a substance changes from one type of matter into another.

Chemical change

5

Reactions that absorb energy as they occur are called

Endothermic

6

Reactions that give off energy as they occur are called

Exothermic

7

Fire is what

And exothermic chemical reaction called combustion that releases energy in the form of heat and light

8

If your potential energy is released during combustion and converted into what

Kinetic Energy

9

Some solid fuels particularly those that are porous can char and undergo oxidation on the fuel surface. This oxidation is known as

Nonflaming or smoldering combustion

10

The old combustion model composing of oxygen fuel and heat

Fire triangle

11

The new fire behavior model which explains smoldering combustion comprising of heat fuel or reducing agent chemical change reaction and oxidizing agent

Fire tetrahedron

12

The fire tetrahedron is comprised of four elements

Fuel. Auction. Heat. Self sustained chemical reaction

13

The material or substance being oxidized or burned in the combustion process

Fuel, reducing agent

14

In organic fuels such as hydrogen or magnesium do not contain what

Carbon

15

Organic fuels contain what

Carbon

16

Organic fuel can be for the divided into two categories

Hydrocarbon-based, cellulose based

17

To key factors influencing the combustion process are

Physical state and its distribution or orientation

18

Three physical states of matter which fuel may be found

Solid liquid or gas

19

For flaming combustion to occur fuels must be in what state

Gaseous

20

A fuel that has definite size and shape

Solid fuel

21

A type of plastic that is not readily change its physical shape when exposed to heat

Thermosetting plastics

22

When wood is first heated what is released as the wood dries

Water vapor

23

As surface increases the more material is exposed to heat in this generates combustible pyrolysis products more quickly making the fuel easier to ignite is the explanation of what

Surface to mass ratio

24

The distribution and orientation of a solid fuel, vertical/horizontal, relative to the source of heat also affects what

The way it burns

25

A state of fuel that has mass and volume but no definite shape

Liquid fuel

26

Gasoline has a specific gravity of what

Less than one

27

Liquid fuels have a number of characteristics that contribute to their abilities to ignite and burn. These characteristics include the following

Solubility.
Vaporization.
Vapor pressure.
Flashpoint.
Flammable/combustible liquids.
Surface area

28

Flammable liquids have a flashpoint that is less than what temperature

Less than 100°F

29

Combustible liquids have a flashpoint that are greater than what temperature

Greater than 100°F

30

Transformation of a liquid to a vapor or gaseous state

Vaporization

31

Pressure produced or exerted by the vapor that a liquid releases. As a liquid is heated this increases along with the rate of vaporization

Vapor pressure

32

The temperature at which a liquid releases sufficient vapors to ignite but not sustain combustion, commonly indicate flammability hazard of liquid fuels

Flashpoint

33

Extent to which a substance will mix with water

Solubility

34

Substances that readily mix with water such as alcohol

Polar solvents

35

Materials that are miscible in water will mix in

Any proportion

36

Weight of a given volume of pure vapor or gas compared to the weight of an equal volume of dry air at the same temperature and pressure

Vapor density

37

The most dangerous type of all fuel types

Gaseous fuel

38

State of fuel that mass but no definitive shape or volume

Gaseous fuel

39

A gas that has a vapor density less than one and rises

Methane

40

Liquid petroleum gas tends to sink and has a vapor density less or greater than one

Greater than one

41

Vapor density is generally specified at what temperature

68°F

42

The primary oxidizing agent in most fires is what

Oxygen

43

At normal ambient temperatures materials can ignite and burn at oxygen concentrations as low as what percent

14%

44

Some petroleum-based materials will auto ignite during what condition

Oxygen concentrations are higher than 21%

45

And industrial bleaching agent used to typically for paper manufacturing

Hydrogen peroxide

46

many materials that do not burn at normal oxygen levels and burn readily and what type Of atmosphere

Oxygen enriched

47

The fuel to air concentration range that supports combustion is called

The flammable range. Or explosive range

48

Lowest Limit at which a flammable gas or vapor will ignite

Lel

49

Upper limit at which flammable gas or vapor will ignite

UFL

50

True/false. Variations in temperature and pressure can cause the flammable range to vary considerably

True

51

Generally increases in temperature or pressure brought in the range of

Flammability

52

Decreases in temperature and pressure does not narrow the flammable range. True/false

False it does narrow it

53

Energy exists in two states

Potential and kinetic energy

54

Potential energy is

The energy possessed by an object that may be released in the future

55

The energy possessed by a moving object is

Kinetic energy

56

Form of energy associated with the motion of atoms or molecules and capable of being transmitted through solid and fluid media by conduction convection and radiation

Heat

57

Heat moves away from fuel that is burning toward what

Fuel that is not burning

58

Flammable Range of methane

5% through 15%

59

Flammable range of propane

2.1% -9.5%

60

Flammable range of carbon monoxide

12% -75%

61

Flammable range of gasoline

1.4% -7.4%

62

Flammable range of diesel

1.3% -6%

63

Flammable range of ethanol

3.3% -19%

64

Flammable range of methanol

6% -35.5%

65

There are two forms of ignition

Piloted ignition and autoignition

66

This type of ignition occurs when a mixture of fuel and oxygen encounters and external heat source with sufficient heat energy to start the combustion reaction

Piloted ignition

67

This type of ignition occurs without any external flame or spark to ignite fuel gases or vapors

Autoignition

68

Temperature to which the service of a substance must be heated for ignition and self sustained combustion to occur

Autoignition temperature

69

The autoignition temperature is always higher than what

The pilot ignition temperature

70

The most common type of ignition is

Piloted ignition

71

Heat energy usually comes from one or more of the following sources

Chemical. Mechanical. Electrical. Light. Nuclear. Sound

72

The most common sources of heat that results in the ignition of fuel

Chemical and electrical and mechanical energy

73

The most common source of heat in combustion reactions

Chemical heat energy

74

Oxidation almost always results in the production of what

Heat

75

Heating that occurs when a material increases in temperature without the addition of external heat

Self heating, or spontaneous heating

76

For spontaneous ignition to occur the following set of circumstances must be met

Insulate of property of material must be so that it cannot dissipate as fast as it is being generated.
Rate of the production great enough to raise temperature to ignition point.
Available air supply adequate to support combustion

77

Heat generated as electrical current passes through a conductor such as copper wire

Electrical heat energy

78

Electrical heating can occur in several ways including the following

Resistance heating.
Overcurrent or overload.
Arcing.
Sparking

79

Heat produced when electric current flows through a conductor

Resistance heating

80

Unintended resistance heating

Overcurrent or overload

81

High temperature luminesce electric discharge across a gap or through a medium such as charted insulation

Arcing

82

Form of heat energy generated by friction or compression

Mechanical heat energy

83

Movement that results in the generation of heat and or Sparks, created went to services move against each other

Heat of friction

84

Energy created when a gas is compressed

Heat of compression

85

In order for heats to be transferred from one object to another the two objects must be a different

Temperatures

86

The transfer of heat from object to object is measured as

Energy flow overtime

87

Transfer of heat within an object or to another object by direct contact, heat flow through and between solids

Conduction

88

The transfer of heat energy for my fluid, liquid or gas, to a solid surface

Convection

89

Transmission of energy as an electromagnetic wave such as lightwaves radio waves are x-rays without an intervening medium

Radiation

90

All matter having a temperature above what will radiate heat energy

Absolute zero

91

This type of he becomes the dominant Mode of heat transfer when a fire grows in size and he can have significant effect on the ignition of objects located some distance away

Radiant heat

92

A wide range of factors influence radiant heat transfer including the following

Distance from heat source.
Temperature difference between source and material heated.
Collar and reflective qualities of heat source and material heated

93

As temperature of the heat source increases the radiant energy increases by a factor of what

Increases by a factor to the fourth power

94

Materials that absorbs heat but do not participate actively in the combustion reaction

Passive agents

95

A passive agent that slows the absorption of heat energy in the ignition and combustion process

Fuel moisture

96

Insulating materials retard the transfer of heat primarily by what

Slowing conduction from one body to another

97

Type of heat transfer that is the cause of most exposure fires

Radiation

98

A fourth method for heat transfer that has historically been used by the fire service is actually a combination of conduction and radiation rather than an independent method of heat transfer

Direct flame contact

99

Free radicals combined with oxygen or with the elements that form the fuel material producing what

Intermediate combustion products, new substances

100

Free radicals

Atom or group of atoms that has at least one unpaired electron, unstable and reactive

101

Methane burns it creates what

Carbon and hydrogen

102

When methane burns it creates what

Carbon monoxide and formaldehyde

103

Surface combustion also involves oxidation at the surface of the actual material without initiation or continuation of the chemical change reaction found in what type of combustion

Flaming combustion

104

Surface or smoldering combustion cannot be extinguished by chemical inhibition because

There are no flames and related chemical change reaction

105

Halon agents extinguish fires by

Interrupting the chemical chain reaction

106

An aerosol comprised of fire gases paper and solid particles

Smoke

107

Carbon monoxide is the byproduct of

Incomplete combustion of organic materials

108

Most common products of combustion encountered in structure fires

Carbon monoxide

109

This is Produced in The combustion of materials containing nitrogen and a significant byproduct of the combustion of polyurethane foam

Hydrogen cyanide

110

Product of complete combustion of organic materials is non-toxic but is an asphyxiant by displacing oxygen

Carbon dioxide

111

This class of fire involves ordinary solid combustible materials such as would cloth paper rubber and plastics

Class a fires

112

This class of fire involves my flammable and combustible liquids and gases such as gasoline oil and alcohol

Class B fires

113

Class c fires involve what

Energize electrical equipment

114

Combustible metals such as aluminum magnesium potassium sodium titanium and zirconium form this class of fire

Class D

115

True/false. No single extinguishing agent effectively controls fires and all combustible metals

True

116

Class K fires involve

Oils and greases normally found in commercial kitchens using deep fryer's

117

A process caused by class K extinguishing agents turning fats and oils into a soapy foam that extinguishes a fire

Saponification

118

When sufficient oxygen is available for development is controlled by the characteristics and configuration of the fuel and is considered to be

Fuel controlled

119

When fire development is limited by the air supply the fire is set to be

Ventilation controlled

120

Four stages of fire development

Incipient. Growth. Fully developed. Decay

121

Ignition occurs when all three elements of the fire triangle come together and combustion happens true or false

true

122

Once combustion begins development of an incipient fire is largely dependent on the characteristics and configuration of

Fuel involved

123

To draw in and transport as solid particles or gas, by the flow of a fluid

Entrain

124

The ceiling Jet is otherwise known as

Mushrooming

125

First affect caused by the transition into the growth stage is the amount of air that is

Drawn into the plume

126

What determines the amount of air that is entrained and thus the amount of cooling that takes place

Location of fuel in relation to the compartment walls

127

Thermal layering, isolated flames, rollover, and flashover are all found during what stage of fire

Growth stage

128

Pocket flames that may be observed moving through the hot gas layer above the neutral plane is sometimes referred to as

Ghosting

129

The rapid transition between the girls and fully developed by her stages but not a specific event like ignition

Flashover

130

When the temperature in a compartment results in the simultaneous ignition of all the combustible contents in the space

Flashover

131

Flashover temperature is typically occur between what

Between 900°F and 1200°F

132

The temperatures associate with flashover is a range that usually correlates with the autoignition temperature of what, commonly produced gas

Carbon monoxide

133

To develop flashover conditions the fuel must have sufficient

Heat energy

134

A seal room might not provide enough what for a developing fire to reach flashover

Ventilation, oxygen

135

Measurement of the amount of heat released when a material burns as stated in kilowatts or BTU

Heat release rate

136

Most fires they grow beyond incipient stage become what controlled

Ventilation controlled

137

The compartment fire will Decay as the fuel is consumed or as the oxygen concentration

Falls to the point where Flaming combustion can no longer be supported

138

Instantaneous explosion or rapid burning of superheated gases that occurs when oxygen is introduced into a smoldering fire in a confined space

Backdraft

139

Flammable products of combustion can accumulate within the compartment and if with in the flammable range they can ignite resulting in

Smoke explosion

140

Ignition of accumulated flammable products of combustion

Smoke explosion

141

A Backdraft will occur if the accumulated products of combustion are at or above their

Ignition temperature

142

The following factors influence fire development with in a compartment

Fuel type.
Availability and location of additional fuel.
Compartment volume.
Ventilation.
Thermal properties of compartment.
Ambient conditions.
Effects of changing conditions.

143

In a compartment fire the most fundamental fuel characteristics influencing fire development are

Mass and surface area

144

A number of factors influence the availability and location of additional fuels including the following

Building configuration.
Contents of building.
Construction of the building.
Interior finish materials.
Fuel proximity and continuity.
Fire location

145

Amount of fuel present express quantitatively in terms of weight of fuel per unit area

Fuel load

146

All things being equal a fire and a large compartment will develop more slowly than one in

A small compartment due to greater volume of air and material that must be heated

147

Firefighters influence our behavior by doing one or more of the following actions

Reducing temperature.
Eliminating fuel.
Separating the fire from available fuel.
Changing oxygen concentration.
Interrupting chemical chain reaction

148

When water is converted into steam at 212°F expands approximately how many times

1700 times

149

Simplest method of fuel removal is

To allow the fire to burn until all fuel is consumed

150

For fires involving pesticides or flammable liquid spills what might be the most appropriate action to extinguish

Allowing fuel to burn out because of possible environmental harm from water run off

151

Example of oxygen exclusion to extinguish fire would be

Covering a cooking fire pan with a lid. Dry chemical extinguisher

152

Halogenated agents are effective in extinguishing gas and liquid fuels because

They interrupt chemical change reaction and the fuels must flame to burn

153

The primary duty of the fire inspector is to ensure

The life safety of all citizens and fire emergency services responders