meodingu Kig 'Yar
Number of posts : 141 Age : 39 Registration date : 2010-10-13
| Subject: Extinguishing fires Thu Oct 14, 2010 12:58 am | |
| Extinguishing fires Water is used for fighting wildfires. Water has a high heat of vaporization and is relatively inert, which makes it a good fire extinguishing fluid. The evaporation of water carries heat away from the fire. However, only distilled water can be used to fight fires of electric equipment, because impure water is electrically conductive. Water is not suitable for use on fires of oils and organic solvents, because they float on water and the explosive boiling of water tends to spread the burning liquid. Use of water in fire fighting should also take into account the hazards of a steam explosion, which may occur when water is used on very hot fires in confined spaces, and of a hydrogen explosion, when substances which react with water, such as certain metals or hot graphite, decompose the water, producing hydrogen gas. The power of such explosions was seen in the Chernobyl disaster, although the water involved did not come from fire-fighting at that time but the reactor's own water cooling system. A steam explosion occurred when the extreme over-heating of the core caused water to flash into steam. A hydrogen explosion may have occurred as a result of reaction between steam and hot zirconium. Brick Veneer Sidingmens silver rings | |
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