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38 Cards in this Set
- Front
- Back
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Class A fire |
Fueled by residue leaving materials. Ash from; paper, wood, cloth, rubber and some plastics |
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Class b fire |
Involving Flammable liquids in gasses. Ex. Gasoline, paint thinner, kitchen grease, propane and acetylene |
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Class C fires |
Involve energized electrical wiring or equipment Motors, computers, panel boxes |
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Class d fires |
Involving exotic metals like magnesium, sodium, titanium |
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Extinguisher types |
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How to use extinguisher |
Pull pin Aim at fire base Squeeze trigger Sweep side to side |
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Combustion |
Self sustaining process of rapid oxidation of fuel which produces heat and light |
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Oxidation |
Normal air has 21% O2 Instantaneous oxidation-explosion Slow oxidation- rust Rapid oxidation- fire (steady, free and smoldering) |
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Self oxidizing agents and oxidizing agents |
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Fire |
Visual byproducts of combustion Result of rapid combustion |
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Fire point |
Temp at which fuel will make sufficient vapors to support continuous combustion when ignited. Fire is usually a few degrees over Flashpoint |
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Flash point |
Min temp when liquid fires give off enough vapor to form an ignitable mixture with air near the surface. At this temp, ignited vapors will flash but not burn |
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Ignition temperature |
Min temp to which fuel on air must be to start self sustained combustion without separate ignition source |
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Heat energy |
Movement of molecules setting matter in motion |
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Categories of heat energy |
Chemical Electrical Mechanical Nuclear Solar |
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Chemical |
Combustible in contact with oxygen results in heat Match burning heat is chemical heat energy |
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Heat of combustion |
Amount of heat generated by combustion process Depends on material |
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Spontaneous or self heating |
When organic materials get hotter without external heat help. Ex. Oil soaked rags rolled in a ball to decrease ventilation |
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Materials subject to spontaneous heating |
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Electrical heat energy |
Resistance heating- by passing electrical current through a conductor such as a wire Increased when wire isn't large enough for current amount Overloaded wires Tightly wound conductor |
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Dielectric heating |
Result of pulsating DC or AC at a high frequency on a non conductive material |
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Leakage current heating |
Insufficient insulation if conductor |
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Arcing |
Interrupted current flow -Open switch -Loose connection -Arc welder |
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Static electricity |
+ charge on 1 sfc contacting - on another Both naturally attracted to each other and want to be evenly charged Electronic bonding/ grounding needed when transferring fuel from 1 tank to another |
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Mechanical heat energy |
Diesel engines use heat of compression Rubbing sticks for a fire uses heat of friction |
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Nuclear and solar energy |
Splitting atoms- fission Combining atoms- fusion |
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Heat transfer |
Heat flows from hot to cold untill both = Heated air and gas and liquids expand and rise Heat waves don't easily go thru solids |
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Conduction |
Method of heat transfer hot to cold Good conductors aluminum, copper iron Poor conductors, Fibrous, felt, cloth, paper, liquids, gasses |
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Convection |
Example of heated air and gas expanding and rising Direct flame contact is convection |
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Radiation |
Energy transmission as an electromagnetic wave like light, radio, xray Commonly called heat waves Will travel thru space at light speed untill it reaches opaque. Opaque will radiate heat off its surfave |
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Fire behavior/fuel types |
Solid Liquid Gas All fuels must be gas to combust Solids need Pyrolysis- decomp with heat Liquids need to vaporize- less heat than for solids Gas. Don't need but hardest to contain |
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Burning process |
Vapor/air mixture reached- raise temp to ignition temp for self sustaining combustion Flaming or smoldering |
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Reduced O2 effects |
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Fire phases |
Incipient Steady Hot-smoldering |
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Thermal layering |
Gas forms in layers based on temp |
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Combustion products |
Heat Flame Smoke Fire gases |
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Extinguishing methods |
Reduce temp Remove fuel Exclude O2 Inhibits chemical chain run |
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Fire classes |
A- combustible materials B- Flammable liquids C- Electrical D- combustible metals |
