Essentials Of Ff Chap 03

Front 1

Autoignition Temperature

Back 1

Same as ignition temperature except that no external ignition source is required for ignition because the material itself has been heated to ignition temperature.

Front 2

Backdraft

Back 2

Instantaneous explosion or rapid burning of superheated gases that occurs when oxygen is introduced into an oxygen-depleted confined space. The stalled combustion resumes with explosive force. It may occur because of inadequate or improper ventilation procedures.

Front 3

Boiling Liquid Expanding Vapor Explosion (BLEVE)

Back 3

Rapid vaporization of a liquid stored under pressure upon release to the atmosphere following major failure of its containing vessel. The failure of the containing vessel is the result of over-pressurization caused by an external heat source causing the vessel to explode into two or more pieces when the temperature of the liquid is well above its boiling point at normal atmospheric pressure.

Front 4

Carbon Dioxide (CO2)

Back 4

Colorless, odorless, heavier than air gas that neither supports combustion nor burns. CO2 is used in portable fire extinguishers as an extinguishing agent to extinguish Class B or C fires by smothering or displacing the oxygen.

Front 5

Carbon Monoxide (CO)

Back 5

Colorless, odorless, dangerous gas (both toxic and flammable) formed by the incomplete combustion of carbon. It combines more than 200 times as quickly with hemoglobin as oxygen, thus decreases the blood’s ability to carry oxygen.

Front 6

Conduction

Back 6

Physical flow or transfer of heat energy from one body to another through direct contact or an intervening medium from the point where the heat is produced to another location or from a region of high temperature to a region of low temperature.

Front 7

Convection

Back 7

Transfer of heat by the movement of heated fluids or gases, usually in an upward direction.

Front 8

Endothermic Heat Reaction

Back 8

Chemical reaction in which a substance absorbs heat energy.

Front 9

Exothermic Heat Reaction

Back 9

Chemical reaction between two or more materials that changes the materials and produces heat, flames, and toxic smoke.

Front 10

Fire Point

Back 10

Temperature at which a liquid fuel produces sufficient vapors to support combustion once the fuel is ignited. The fire point is usually a few degrees above the flash point.

Front 11

Fire Tetrahedron

Back 11

Model of the four elements/conditions required to have a fire. The four sides of the tetrahedron represent fuel, heat, oxygen, and chemical chain reaction.

Front 12

Flammable Range

Back 12

The range between the upper flammable limit and lower flammable limit in which a substance can be ignited.

Front 13

Flash Point

Back 13

Minimum temperature at which a liquid gives off enough vapors to form an ignitable mixture with air near the liquid’s surface.

Front 14

Flashover

Back 14

Stage of a fire at which all surfaces and objects within a space have been heated to their ignition temperature and flame breaks out almost at once over the surface of all objects in the space.

Front 15

Heat Release Rate (HRR)

Back 15

Total amount of heat produced or released to the atmosphere from the convective-lift fire phase of a fire per unit mass of fuel consumed per unit time.

Front 16

Incipient Phase

Back 16

First phase of the burning process in a confined space in which the substance being oxidized is producing some heat, but the heat has not spread to other substances nearby. During this phase, the oxygen content of the air has not been significantly reduced.

Front 17

Kinetic Energy

Back 17

The energy possessed by a moving object.

Front 18

Matter

Back 18

Anything that occupies space and has mass.

Front 19

Miscible

Back 19

Materials that are capable of being mixed.

Front 20

Potential Energy

Back 20

Stored energy possessed by an object that can be released in the future to perform work once released.

Front 21

Radiation

Back 21

The transmission or transfer of heat energy from one body to another body at a lower temperature through intervening space by electromagnetic waves such as infrared thermal waves, radio waves, or X-rays.

Front 22

Reducing Agent

Back 22

The fuel that is being oxidized or burned during combustion.

Front 23

Rollover

Back 23

Condition in which the unburned combustible gases released in a confined space (such as a room or aircraft cabin) during the incipient or early steady-state phase and accumulate at the ceiling level. These superheated gases are pushed, under pressure, away from the fire area and into uninvolved areas where they mix with oxygen. When their flammable range is reached and additional oxygen is supplied by opening doors and/or applying fog streams, they ignite and a fire front develops, expanding very rapidly in a rolling action across the ceiling.

Front 24

Saponification

Back 24

A phenomenon that occurs when mixtures of alkaline based chemicals and certain cooking oils come into contact resulting in the formation of a soapy film.

Front 25

Solubility

Back 25

Degree to which a solid, liquid, or gas dissolves in a solvent (usually water).

Front 26

Specific Gravity

Back 26

Weight of a substance compared to the weight of an equal volume of water at a given temperature. A specific gravity less than 1 indicates a substance lighter than water; a specific gravity greater than 1 indicates a substance heavier than water.

Front 27

Thermal Layering (of Gases)

Back 27

Outcome of combustion in a confined space in which gases tend to form into layers, according to temperature, with the hottest gases are found at the ceiling and the coolest gases at floor level.

Front 28

Vaporization

Back 28

Process of evolution that changes a liquid into a gaseous state. The rate of vaporization depends on the substance involved, heat, and pressure.

Front 29

types of electrical heat energy

Back 29

resistance, arcing, sparking, and overloading

Front 30

mechanical energy

Back 30

produced by compression or friction

Front 31

passive agents

Back 31

absorb heat but do not participate in combustion

Front 32

vapor density

Back 32

density of gas in relation to air

Front 33

sollubility

Back 33

extent to which a substance will mix with water

Front 34

HRR

Back 34

heat release rate- amount of energy released when a specific amount of that fuelis oxidized

Front 35

common oxidizers other than oxygen

Back 35

calcium hypochlorite, chlorine, ammonium nitrate, hydrogen peroxide, methyl ethyl ketone peroxide

Front 36

oxygen depleted and oxygen enriched percentages

Back 36

less than 19.5% and more than 23.5%

Front 37

ghosting

Back 37

during growth stage, pockets of flames move through hot gas layer above the neutral zone- classified as a fire gas ignition

Front 38

factors that affect fire development

Back 38

fuel type, availability and location of additional fuel, compartment volume and ceiling height, ventilation, thermal properties of enclosure, ambient conditions, impact of chinging conditions

Front 39

Fire control methods

Back 39

temperature reduction, fuel removal, oxygen exclusion, and chemical flame inhibition

Front 40

physical change

Back 40

stays chemically the same but changes in size shape or appearance

Front 41

chemical change

Back 41

substance changes from one type of matter to another

Front 42

chemical heat energy

Back 42

self heating, spontaneous heating. heat cannot dissipate, autoignition temperature is raised, poor ventilation.

Front 43

hydro carbon fuels

Back 43

hydrogen and carbon base- gasoline, oil and plastic based, organic

Front 44

cellulose based fuels

Back 44

wood and paper, organic

Front 45

atmospheric pressure

Back 45

14.7 psi, the pressure a liquid must overcome to achieve vaporization