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Firefighting

 



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Overview
Would you know what to do if a fire suddenly broke out in your home? You need to understand how fire burns, how heat energy is transferred in a fire, and how to protect yourself and others from it. Imagine a fire triangle --one side is oxygen, one side is fuel, and one side is energy. Fire needs a source of oxygen (air, ozone, etc.) which chemically combines with fuel at a high enough temperature to maintain the fire's combustion process. If one of these three factors is missing, fire cannot exist. Fire fighters extinguish fires by removing one or more of the sides of the triangle. Burning releases chemical energy, resulting in increased molecular motion and emission of electromagnetic waves. This increased molecular motion is detected as a rise in temperature. The energy is removed as heat by conduction, convection, and radiation. To occur, chemical reactions like burning often require a high molecular agitation--that is, a high temperature. Conduction is the transport of heat through solids by direct contact. This transfer goes from molecule to molecule down the chain, like a row of dominos. You feel the effect of conduction whenever you touch a hot object. Convection is the transfer of heat in fluids. The process begins by heating a fluid. As the fluid warms, it becomes less dense and rises. Colder, denser fluid then sinks down and takes the place of the warmer fluid, creating a convection cell. Radiation is the transfer of energy through empty space or transparent materials. The energy travels in waves from the source, such as the energy that travels from the sun to Earth or the heat you feel coming from a stove. Radiation causes the temperature of materials around a fire to rise. If the temperature increases, the material may reach its ignition temperature and burst into flames, adding more fuel to the fire. Almost 70% of fatal house fires occur at night. Smoke is the most frequent cause of death, since it displaces the oxygen we breath and fills the air with poisonous toxins. After only a few seconds in a smoke-filled room, you can become disorientated and experience distorted judgment. You should know what to do in the event of a fire. Plan escape routes from your apartment or home and practice using them. Install smoke alarms and maintain them by cleaning and testing them monthly. Learn fire prevention and safety procedures so you know what to do if a fire breaks out.

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