1. FIRE BEHAVIOR State of Georgia BASIC FIRE FIGHTER TRAINING COURSE Module 1

2. Fire Behavior (M-1) 2 FIRE Fire is the self-sustaining process of rapid oxidation of a fuel, which produces heat and light

3. Fire Behavior (M-1) 3 Oxygen Fuel Heat FIRE TRIANGLE

4. Fire Behavior (M-1) 4 Oxygen FIRE TRIANGLE  Oxygen (O 2 ) supports combustion and life  21% O 2 in air  14-16% O 2 necessary to support flame serious impairment of personnel  Below 10% O 2 combustion will slow then stop unconsciousness will occur in personnel  Some fuels contain oxygen

5. Fire Behavior (M-1) 5 Fuel FIRE TRIANGLE  Physical States Solid –wood, paper, plastics –converted to gas by pyrolysis –size and shape of fuel effects ease of ignition and rate of burning Liquid –gasoline, kerosene, paint thinner –vaporization produces gas Gases –natural gas, LP gas, acetylene

6. Fire Behavior (M-1) 6 Heat FIRE TRIANGLE  Sources of heat energy Chemical –heat of combustion –spontaneous heating Electrical –arcing –resistance –static discharge Mechanical –friction –compression Solar –sun Nuclear

7. Fire Behavior (M-1) 7 FIRE TRIANGLE Oxygen Fuel Heat

8. Fire Behavior (M-1) 8 A 3-dimensional representation used to explain the concept of fire as it produces flaming combustion FIRE TETRAHEDRON Chemical Chain Reaction Oxygen Heat Fuel

9. Fire Behavior (M-1) 9 CHEMICAL CHAIN REACTION In the burning process fuel elements are released by heat produced by the fire. These elements join in the fire to produce more heat which releases more fuel elements FIRE TETRAHEDRON

10. Fire Behavior (M-1) 10 PRODUCTS OF COMBUSTION  Heat  Smoke  Light  Fire Gases

11. Fire Behavior (M-1) 11 THE BURNING PROCESS Stages or Phases of Burning Within a Structure  Oxygen content: 20% - 21%  Temperature: slightly elevated  Once ignited, the fire is small and confined to material first ignited Incipient, Ignition, Growth

12. Fire Behavior (M-1) 12  Oxygen Content: 15% - 19%  Temperature: may exceed 1000 0 F  Rollover is possible  Fire spreads rapidly  Flashover is possible THE BURNING PROCESS Stages or Phases of Burning Within a Structure Steady State / Free Burning Fully Developed

13. Fire Behavior (M-1) 13 A point at which the rate of heat release begins to decline as the fire consumes the fuel THE BURNING PROCESS Stages or Phases of Burning Within a Structure Decay

14. Fire Behavior (M-1) 14 THE BURNING PROCESS Stages or Phases of Burning Within a Structure

15. Fire Behavior (M-1) 15 THERMAL LAYERING The tendency of heated air and gases to form into layers in a confined room or building according to temperatures of the gases. Coolest Gases Hottest Gases

16. Fire Behavior (M-1) 16  Use straight stream or very narrow fog pattern  Apply water to burning material (direct attack)  Do not flow water too long THERMAL LAYERING To avoid upsetting the Thermal Layering:

17. Fire Behavior (M-1) 17 An explosion or very fast burning of heated gases resulting from the introduction of oxygen when air is admitted to an overheated room or building that is heavily charged with smoke and fire gases, depleted of oxygen, and with extremely high temperatures BACKDRAFT

18. Fire Behavior (M-1) 18 CONDITIONS NEEDED FOR A BACKDRAFT  Heavy concentration of gases (Dense Smoke)  Unventilated confined space  Extreme heat build-up

19. Fire Behavior (M-1) 19  Little or no visible flame (Smoldering)  Building may appear to “breath” as smoke leaves building in “puffs” (intervals)  Black smoke becoming dense gray-yellow  Windows turn extremely black and cracked  Muffled sound BACKDRAFT INDICATORS

20. Fire Behavior (M-1) 20 A fire condition that takes place when unburned combustible gases released during the incipient stage, which have collected at the ceiling, ignite and a fire front develops that expands very rapidly across the ceiling ROLLOVER

21. Fire Behavior (M-1) 21 A condition that occurs when a room or other area becomes heated to a point that ALL contents of the room reach their ignition temperature and ignite simultaneously FLASHOVER

22. Fire Behavior (M-1) 22 METHODS of HEAT TRANSFER  Conduction heat travels through intervening medium metals are good conductors –pipes –steel beams  Convection heat travels through air currents hot air rises  Radiation heat waves are similar to rays of the sun travel in all directions until they strike an object unaffected by wind

23. Fire Behavior (M-1) 23 METHODS of EXTINGUISHMENT  Reduce Temperature cool with water  Remove Fuel turn off the valve (liquids & gases) remove solid fuel from path of fire  Exclude Oxygen smother with dirt or foam blanket flood area with inert gas (CO 2 )  Break Chemical Chain Reaction some fire extinguisher agents (dry chemical)