Chapter 4 Fire Dynamics

Fire Science/Behavior

Fires Likely Behavior

• Fire science

• The combustion process

• Fire behavior and its relationship to various materials and environments

• Classifications of fires and their corresponding extinguishing agents

• Recognition of fire behavior indicators, fire development patterns, and the potential for rapid fire development

• Various ventilation and suppression tactics used as tools for controlling fires

Understanding

• Fire

• Heat

• Temp.

• Combustion

• All fire need heat-producing chemical

• Fuel and Oxidizer

• Oxidizer not combustible, enhance fire

Physical Science

• Matter

• Energy

  • Potential energy (amount of energy object can release)

  • Heat of combustion (energy before ignition based on chemical)

  • Kinetic energy (energy moving object possesses, molecules vibrating)

  • Chemical, Thermal, Mechanical, Electrical, Light, Nuclear, Sound

• Physical change (water to ice/boiling)

• Chemical change (oxidation: rust, explosion)

Measurement

• Joules (J) Internal System of Units (SI)

• Quantity of heat needed to change temp of 1 gram of water by 1 degree Celsius is 4.2 joules

• British Thermal Unit (Btu)

• Amount of heat to change temp of 1 pound by 1 degree Fahrenheit

• Joules to BTU 1 055 J = 1 BTU

Reactions

• Exothermic (Reactions that emit energy as they occur)

• Endothermic (Reactions that absorb energy as they occur [water to steam])

Fire Triangle

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fire

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fire

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