CHY 183 Lecture Notes - Lecture 16: Flashover, Arson, Pyrolysis
Document Summary
Arson investigations are complex and difficult to investigate. Detect and identify relevant chemical materials collected at scene. Ultimate determination of cause of fire must be made by investigator with training/knowledge in fire investigation. Oxidation: oxygen + other substances to produce new ones. Energy: ability of system to do work; takes many forms (heat, light) Exothermic reactions: more energy released than required to initiate reaction. Ignition temperature: min temp needed to spontaneously ignite fuel. Heat of combustion: heat involved with substance burns. Oxygen - in sufficient quantity to combine w/ fuel. Heat - must be applied to initiate the combustion; sufficient heat must be generated to sustain it. Gas - fuel must be a gas (to achieve sufficient reaction rate w/ oxygen to produce flame) Therefore rusting (oxidation of iron) doesn"t cause flames. Liquid - burns when temp high enough to vaporize fuel. Flash point: the lowest temp at which a liquid vaporizes enough to.
