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BASIC Fire Suppression PPT- Civilian.pptx
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- 2. TOPICS • Introduction • FireDynamics • Fire Suppression • Portable Fire Extinguishers • Ventilation • Closing
- 3. 3 BASIC PRINCIPLES OF FIRESCIENCE
- 4. PHYSICAL SCIENCE TERMS 4 Matter Physical materials that occupy space andhave mass Physical change Substance remains chemically the same Changes size, shape, or appearance Chemical reaction Substance changes from one type of matter into another
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- 7. OXIDIZERS N O TC O MB U STI B L E WI L L SU P PO RT O R EN HA N C E C O MB U STI O N 7
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- 9. POTENTIAL AND KINETICENERGY 9
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- 12. FIRE TETRAHEDRON 12 • Fuellimited • Air Limited • Brake-the-Chain
- 13. NONFLAMING COMBUSTION 13 Produces a smolderingglow at the material’s surface Burning on or near fuel’s surface at oxygen contact
- 14. FLAMING COMBUSTION 14 Correct ratioof gaseous fuel mixes with oxygen and heats up to ignition temperature Flames are produced above the material surface
- 15. FLAMING COMBUSTION 15 Heat source pyrolizesfuel, creating fuel gases Gases mix with oxygen Gases ignite and create fire Fresh oxygen is pumped in and products of combustion are pumped out Fire generates heat, which transfers to gaseous combustion products Combustion products expand to fill the compartment
- 16. • Fuel’s chemicalcomposition changes as it burns, which produces new substances • Simply described as heat and smoke • Exposure to toxic gases in smoke and/or lack of oxygen caused most fire deaths • Smoke is an aerosol that is a product of incomplete combustion PRODUCTS OF COMBUSTIOIN 16
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- 19. Portable Fire Extinguishers19 Classified according to type of fire they are designed to extinguish Some are suitable for more than one class of fire; some only designed for a particular class Should only be used for intended fire type(s) Certain extinguishing agents are only effective on certain classes of fuels
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- 21. Class A- OrdinaryCombustibles 21 • Textile s • Paper • Plastic s • Rubbe r • Wood Class A fuel examples • Water • Water-based agents • Dry chemicals • Monoammonium phosphate • Ammonium Sulfate Extinguishing agents
- 22. Class A- OrdinaryCombustibles 22 • Rated from 1-A through 40-A • Rating is based on amount of water and duration and range of discharge
- 23. Class B- Flammableand Combustible Liquids 23 • Alcohol • Gasoline • Oils • Liquefied Petroleum Gas - LPG Class B fuel examples • Carbon Dioxide (CO2) • Dry Chemicals • Class B Foam Extinguishing agents
- 24. Class B- Flammableand Combustible Liquids 24 • Rated from 1-B through 640-B • Rating is based on approximate square foot (meter) area of flammable liquid fire that a nonexpert operator can extinguish using one full extinguisher • Expected to extinguish 1 square foot (0.09m2 ) for each numerical rating or value
- 25. Class C –Energized Electrical Equipment 25 Extinguishing agents • Water and water-based agents cannot be used until electricity is shut off • Class C agents will not conduct electricity • Once power supply is off, treat as a Class A or B fire Class C extinguishers • Not specifically rated based on capability tests • Class C rating assigned in addition to Class A and/or B rating
- 26. Class D –Combustible Metals and Alloys 26 Class D fuel examples • Titanium • Lithium • Magnesium • Potassium • Sodium Magnesium • Fires identified by bright white emissions during combustion • Common uses: cameras, laptops, luggage, box springs, automobile wheels and transmissions
- 27. Class D –Combustible Metals and Alloys 27 Extinguishing Agents • Dry powder (Dry Powder is not Dry Chemical) ONLY USE D RATED EXTINGISHERS Class D Extinguishing Ratings • Variety of factors considered during testing • No Numerical rating • Class D agents not rated for use on other classes of fire.
- 28. Class K –Combustible Cooking Oils 28 Class K fuel examples • Vegetable or animal fats • Oils that burn at high temperatures Locations • Private homes • Commercial and institutional kitchens • Industrial cooking facilities
- 29. Class K –Combustible Cooking Oils 29 Class K extinguishers Wet chemical systems and portable extinguishers Work because of saponification (Alkaline+fats=Soap) Wet chemical agents contain alkaline mixture to suppress vapors and smother the fire To meet the minimum criteria for Class K rating, agents must extinguish fire with surface area of 2.25 square feet (0.2 m2 )
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- 32. Operational Characteristics ofPortable Fire Extinguishers 32
- 33. Operational Characteristics ofPortable Fire Extinguishers 33
- 34. Portable Fire ExtinguisherMechanisms 34 Manual pump Stored pressure Pressure cartridge
- 35. Stored-Pressure Water Extinguishers35 Wet Chemical Class K fires Potassium-based, low- pH agent that extinguishes by saponification Carried on some apparatus
- 36. Clean Agent Extinguishers 36 • Cooland smother Class A and B fires • Inhibit sustained chemical reaction in Class C fires • Nonconductive and can extinguish Class C fires • Developed to replace Halons Uses Halogenated agents • Effective for fires containing materials that are easily damaged by water or dry chemicals • Damaging effect on ozone layer Halotron • U.S. EPA approved alternative clean agent • Does not harm the ozone
- 37. Carbon Dioxide (CO2)Extinguishers 37 Uses • Handheld or wheeled units • Most effective for Class B and C fires Function and application Limited discharge reach Winds disperse extinguishing agent Do not require freeze protection Store CO2 under its own pressure as liquefied gas Discharges agent through plastic or rubber horn at the end of a hose or tube Gaseous discharge usually forms dry ice crystals or “snow” Gas displaces oxygen and smothers the fire Little cooling effect Does not suppress surface vapors; fuels may reignite
- 38. Dry Chemical Extinguishers 38 Dry chemical ClassA- B-C fires Class B-C fires Dry powder Only Class D fires
- 39. Dry Power Extinguishers •ClassD fires •No agent will work for all combustible metals 39
- 40. PASS application Method40 Pull Aim Squeeze Sweep