1. Combustion Processes

2. Colorado Fallen Firefighters Memorial May 7, 2011

6. Objectives 1. The fire triangle and it components 2. The fire tetrahedron and its components 3. What are the differences between the two, and why is the fire tetrahedron a better model?

7. What is combustion?  Let’s define and discuss combustion.  What is the definition of combustion?  Is there a difference between fire and combustion?

8. Theories of Combustion  Fire Triangle Fuel Heat Oxygen

9. The Fire Tetrahedron  Fire Tetrahedron Fuel Heath Oxygen Uninhibited Chemical Chain Reaction

10. What is the difference between the two?  What is the difference between the two theories and why is it important?  Which more accurately portrays the combustion process?

11. Fire Classifications

12. How do we establish burning? Ignition Methods of Heat Transfer Flaming Combustion Smoldering Combustion Pyrolysis Orientation Surface to Mass Ratio Extreme Fire Events

15. Questions?  Does anyone have any questions about the material we have discussed?

16. Combustion Process Edition

17. A deflagration resulting from the sudden introduction of air into a confined space containing oxygen-deficient products of incomplete combustion.

18. What is a Backdraft?

19. The lowest temperature at which a combustible material ignites in air without a spark or flame.

20. What is the Autoignition Temperature?

21. A relatively thin layer of flowing hot gases that develops under a horizontal surface (i.e. ceiling) as a result of plume impingement and the flowing gas forced to move horizontally.

22. What is a Ceiling Jet?

23. A rapid oxidation process, which is a chemical reaction resulting in the evolution of light and heat in varying intensities.

24. What is a Fire?

25. A transition phase in the development of a compartment fire in which surfaces exposed to thermal radiation reach ignition temperature more or less simultaneously.

26. What is a Flashover?

27. The rate at which heat energy is generated by burning.

28. What is the Heat Release Rate?

29. A process in which material is decomposed, or broken down, into simpler molecular compounds by the effects of heat alone; often precedes combustion.

30. What is Pyrolysis?

31. The transfer of heat energy from the hot to the cold side of a medium by means of energy transfer from molecule to adjacent molecule, or atom to atom.

32. What is Conduction?

33. The movement of heat energy by the agitation of air molecules that reduces the density of molecules, making heated air lighter than cooler.

34. What is Convection?

35. The combined process of emission, transmission, absorption of heat energy traveling through electromagnetic waves from an area of higher heat energy to an area of lower heat energy.

36. What is Radiation?

37. Heat transfer by flames directly impinging upon materials.

38. What is Direct Flame Impingement?

39. To Do…..  Review Key Terms  Read Chapter 3 (Combustion Process)  Attend weekly Seminar  Respond to the Discussion Board  Complete and Submit the Unit 4 Project  Take the Quiz (this is a graded quiz)  Check out Extra! Extra!

40. Unit 4 Assignment  For each type of heat transfer you see in the video, and using the information we learned this week: 1. Identify the type of heat transfer, and 2. Define why it is that form of heat transfer 3. EXAMPLE: The melting of the lampshade and the burning material landing on the carpet and starting to burn the carpet would be an example of direct flame contact.