Laserfiche WebLink
• Heat Energy - Can be produced by building up molecules (composition) or breaking apart <br />(decomposition) by heat or a solution when materials are dissolved in a liquid, or by combustion. <br />■ Heat Transfer - A law of physics states that heat tends to flow up from a hot substance or place to a <br />cold substance or place. This is through conduction (transfer of heat through a medium such as metals) <br />or through convection (transfer of heat with a medium -usually circulatory). <br />■ Fuels - Those substances that will burn when heat is applied. The most common fuels are not pure <br />elements such as carbon, but compounds and mixtures such as paper and wood. <br />■ Oxygen - Makes up a major portion of the oceans and earth's crust and one-fifth of our atmosphere. <br />Atmospheric oxygen is the major source of oxygen that supports combustion. Oxygen itself does not <br />burn, however, without it, combustion is impossible. Normal burning is the combination of fuels with <br />oxygen under the influence of heat. <br />■ Combustion - A rapid oxidation or chemical combination accompanied by heat. <br />® Oxidation - The ability of materials to produce oxygen during a chemical reaction. <br />■ Spontaneous Combustion - When oxidation is allowed to occur, enough oxygen is available, heat is <br />produced, molecules become more energetic and combine with oxygen at an increasing rate, <br />temperatures rise and visible heat (flames) are produced. <br />Classes of Fires: <br />■ Class A - Ordinary combustibles (wood/paper/textiles) <br />■ Class B - Flammable liquids (gasoline/oils/grease) <br />■ Class C - Live electric (wiring/generators/motors) <br />® Class D - Combustible metals (finely divided form/chips, turnings) <br />Types of Fire Extinguishers: <br />■ Water - extinguisher for ordinary combustible fires <br />• Dry Chemical or CO2 - extinguisher for electrical equipment fires and for flammable liquid fires <br />® Multipurpose Dry Chemical - extinguisher for ordinary combustible fires, liquid fires, and electrical <br />equipment fires <br />• Foam - extinguishing agent for hydrocarbon <br />38 <br />