Fire Behavior Flashcards
What is fire?
The result of rapid combustion reaction.
What is combustion?
The self sustaining process of rapid oxidation of a fuel, which produces heat and light.
What two forms can rapid oxidation (combustion) occur in?
Smoldering fires and steady-state fires.
Boiling point
The temperature of a substance when the vapor pressure exceeds atmospheric pressure. Water 212 degrees.
BTU(British thermal unit)
The amount of heat needed to raise the temperature of 1lbs. of water 1 degree Fahrenheit.
Calorie
The amount of heat needed to raise the temperature of 1 gram, 1 degrees Celsius.
Fahrenheit
Unit temperature measurement in the U. S.
Flame spread
The movement of flame away from the ignition source.
Fire point
The temperature which liquid fuel will produce vapors sufficient to support continuous combustion once ignited.
Flash point
The minimum temperature which a liquid fuel gives off sufficient vapors to form an ignitable mixture with the air near the surface.
Ignition temperature
The minimum temperature to which a fuel in air must be heated to start self-sustained combustion without a separate ignition source.
The 5 general categories of energy are?
Chemical, electrical, mechanical, nuclear & solar.
Chemical heat
The result of a chemical reaction (4 types).
Name the four types of chemical reactions that result in heat production.
Spontaneous heating, heat of combustion, decomposition & solution.
Spontaneous heating is?
The heating of an organic substance without the addition of external heat.
Heat of combustion is?
The amount of heat generated by the combustion (oxidation) reaction.
Heat of decomposition is?
The release of heat from decomposing compounds, usually due to bacterial action (compost pile).
Heat of solution is?
The heat released by solution of a matter in a liquid (the combination of some acids and water).
Name the five causes of electrical heat energy.
Resistance heating, dielectric heating, leakage current heating, heat from arching, and static electricity.
Resistance heating is?
The heat generated by passing an electrical current through a conductor such as a wire or appliance, also when the wire is to small for the amount of current (overloaded extension cord).
Dielectric heating is?
The result of an action of pulsating either direct current (DC) or alternating current (AC) at high frequency on a non conductive material (microwave oven).
Static electricity is?
The buildup of a positive charge on one surface and a negative charge on another.
Mechanical heat energy is?
Generated two ways, by friction and compression.
Leakage current heating occurs?
When a wire is not insulated well enough to contain all the current.
Heat of friction is caused by?
The movement of two surfaces against each other.
Heat from arching occurs?
When the current flow is interrupted, open switch or loose connections.
Heat of composition is created when?
A gas is compressed (SCBA bottle feels warm after filling).
Nuclear heat energy is generated?
When atoms are either split apart (Fission) or combined (Fusion).
Solar heat energy is?
The heat transmitted from the sun in the form of electromagnetic radiation (concentrated to one point).
What three ways can heat transfer?
Conduction, convection and radiation.
Conduction of heat is?
The transfer of heat between two bodies by direct contact or by an intervening heat conducting medium (metal pipe).
Convection of heat is?
The transfer of heat by movement of air or liquid. ( hot air rises so expansion is mostly upward)
Radiation of heat is?
Heat will travel through space (like the sun) until it reaches an object/heating it up.
What are the three states of matter fuel may be found in?
Solid, liquid & gas
What are the six phases of fire?
Incipient, rollover, steady-state burning, flashover, hot-smoldering & backdraft.
The incipient phase is?
The earliest phase of fire beginning with ignition.
The rollover phase of fire is?
When unburdened combustible gasses release during the incipient or early steady-state phase accumulating at the ceiling.
The steady-state phase is?
The stage of the fire where sufficient oxygen and fuel are available for growth.
The flashover phase is?
When flames flashover the entire surface of a room caused by the buildup of heat from the fire itself.
The hot-smoldering phase of a fire is?
When burning is reduced to embers, room is filled with smoke and gasses, room temperature in excess of 1,000 degrees.
The backdraft phase is?
Caused by improper ventilation during the “hot-smoldering” phase.
Eight potential signs of backdraft are?
- Pressurized smoke exiting small openings.
- Black smoke becoming grey/yellow.
- Confinement and excessive heat.
- Little or no visible flame.
- Smoke leaving the building in puffs.
- Smoke stained windows.
- Muffled sounds.
- A sudden rapid movement of air when an opening is made.
The thermal layering of gases is?
The tendency of gases to form layers according to temperature.
What is the fire extinguishment theory?
When the extinguishment of a fire is carried out by limiting or interrupting one or more of the essential elements in the combustion process. Reducing temperatures, eliminating fuel or oxygen, stopping chemical reaction.
Cooling with water would be considered?
Extinguishment by cooling with water.
Stopping the flow of liquids, gaseous fuels or removing solid fuels would be considered?
Extinguishment by fuel removal.
Flooding an area with inert gas such as carbon dioxide would be considered?
Extinguishment by oxygen dilution.
The use of extinguishing agents such as dry chemicals and halogenated hydrocarbons (halons) would be considered?
Extinguishment by chemical flame inhibition.
What are the four classes of fires and extinguishment methods?
Classes A, B, C, D
Class A fires would be considered?
Ordinary combustible materials (wood, cloth, paper, plastic).
Class B fires would be considered?
Flammable combustible liquids and gases (gasoline, oil, lacquer, paint, mineral spirits, & alcohol).
Class C fires would be considered?
Energized electrical equipment (computers, transformers).
Class D fires would be considered?
Combustible metals (aluminum, magnesium, titanium, sodium, potassium).
