Fire Behavior Flashcards
4 Tactical benchmarks during a fire?
1-Fire attach
2- Search
3- Water
4- Ventilation
Priorities (3)
1-Life Safety
2- Incident Stabilization
3- Property and environmental conservation
Uni-directional flow path
Flow from floor to ceiling in 1 direction. Can be deadly, high velocity, high temps and zero visibility.
Bi-directional flow path
Flow through single opening. Flow in two directions. Cool air coming in through bottom, and hot air and gasses going out through the top of the opening. Limits ventilation.
What makes up the fire tirangle?
Oxygen, heat and fuel. The fourth is chemeical reaction.
Flashover
When everything reaches its ignition temperature it ignites all at once.
Things get really hot.
Backdraft and Indicators
Sudden introduction of oxygen into space that is oxygen deficient.
-Smoke stained windows.
-Brownish smoke (incomplete combustion)
-laminar smoke, puffs out
3 products of combustion
Hydrogen cyanide HCN
Carbon Monoxide (CO)-Incomplete combustion
Carbon Dioxide (co2)
Heat transfer methods
Conduction- direct contact to transfer
Convection- movement of heat through air or liquid
Radiation- transfer of heat via waves
4 Stages of Fire
Incipient
Growth
Fully Developed
Decay
Incipient Stage
Initial or beginning stage, can be controlled with extinguisher. limited to localized area.
Growth Stage
Heat release rate has increased where adjacent areas are beginning to pyrolyze. Fire is spreading.
Fully Developed
Reached its peak heat release rate. Occurs after flashover, floor to ceiling burning.
Decay Stage
Decrease in fuel or available oxygen to support combustion, resulting in lower temps.
Thermal Layering
Hottest air/gases rise, once it fills it makes its way down to the floor. Filling the space. Disruption can create a burn hazard-steam. High energy release rate-steam. Water creates rapid movement of air particles/hot air 1700 expansion rate it evaporates.
