Fire triangle

Usually, fire takes place when heat comes in contact with a combustible material. If the combustible material is a solid or liquid, it must be heated to generate sufficientvaporto form a flammable mixture with the oxygen in air. If this flammable mixture is heated to its ignition point (ignited), combustion will occur. Three basic conditions are required for fire to take place. These are fuel, oxygen, and heat. 

Fuel— the reducer any combustible material, solid, liquid or gas. Most solids and liquids must vaporize before they will burn. 

Oxygen—the oxidizer sufficient oxygen must be present in the atmosphere surrounding the fuel for fire to burn. 

Heat—sufficient energy must be applied to raise the fuel to its ignition temperature. 

If one of the sides of the fire triangle is missing, the fire will not start. If one side is removed, the fire will be extinguished. The fire triangle forms the foundation for all methods of fire prevention and firefighting (NFPA, 1997). 

Three factors that create a fire are oxygen, fuel, and heat. These form a chemical reaction that starts a fire. 

Fuel is a combustible substance that can be classified into one of the three physical states solids, liquids, and gases. 

Heat is the third component of fire. Heat sources from fire come from sparks, eleetrieal, friction, etc. 

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The Fire Triangle The well-known/i/ g triangle (see Fig. 26-33) is used to represent the three conditions necessary for a fire (1) fuel, (2) oxygen or other oxidizer (a gaseous oxidizer such as chlorine, a liquid oxidizer such as bromine, or a solid oxidizer such as sodium bro-mate), and (3) heat (energy). 

If one of the conditions in the fire triangle is missing, fire does not occur, and if one is removed, fire is extinguished. Usually a fire occurs when a source of heat contacts a combustible material in air, and then the heat is supphed by the combustion process itself. 

The fire triangle indicates how fires may be fought or prevented ... 

Removal of one of the eorners of the fire triangle normally results in extinguishment of a fire. Propagation of a flame ean also be stopped by inhibition of the ehain reaetions, e.g. using dry powders or organo-halogen vaporizing liquids. 

Draw the fire triangle and explain the simple theory of combustion. 

Fire Triangle Shirt Waste Company, New York March 25, 1911 145 Strengthening of laws concerning alann signals, sprinklers, fire escapes, fire drills... 

Theoretically, if one corner of the fire triangle is eliminated a fire or explosion is impossible. However, in practice, if flammable gases or vapours are mixed with air in flammable concentrations, sooner or later the mixture is likely to catch fire or explode because of the difficulty of eliminating every source of ignition. For reliable control of flammable materials, including combustible dusts, the aim is to remove two corners from the fire triangle. This can include some combination of ... 

The investigation of an industrial fire or explosion invariably starts with an effort to identify each element in the fire triangle. Quite often, the fuel is known and so either the oxidizer or the ignition source becomes the focus of the investigation. For example, in a blender used to mix a... 

Figure 4. The well-known fire triangle, which depicts the three essential requirements...

The essential elements for combustion are fuel, an oxidizer, and an ignition source. These elements are illustrated by the fire triangle, shown in Figure 6-1. 

Two common examples of the three components of the fire triangle are wood, air, and a match and gasoline, air, and a spark. However, other, less obvious combinations of chemicals can lead to fires and explosions. Various fuels, oxidizers, and ignition sources common in the chemical industry are... 

For any fire or combustion explosion to occur, three conditions must be met (as shown in the fire triangle of Figure 6-1). First, a combustible or explosive material must be present. Second, oxygen must be present to support the combustion reaction. Finally, a source of ignition must be available to initiate the reaction. If any of the three conditions of the fire triangle is eliminated, the triangle is broken and it is impossible for a fire or combustion explosion to result. This is the basis for the first six design methods listed above. 

The Fire Triangle The fire triangle is shown in Fig. 23-2. It shows... 

The usual oxidizer in the fire triangle is oxygen in the air. However, gases such as fluorine and chlorine liquids such as peroxides and chlorates and solids such as ammonium nitrate and some metals can serve the role of an oxidizer. Exothermic decomposition, without oxygen, is also possible, e.g., with ethylene oxide or acetylene. 

If any one side of the fire triangle is removed, a fire will not result. In the past, the most common method for fire control was elimination of ignition sources. However, experience has shown that this is not robust enough. Current fire control prevention methods continue with elimination of ignition sources, while focusing efforts more strongly on preventing flammable mixtures. 

FIG. 23-2 The fire triangle showing the requirement for combustion of gases and vapors. [D. A. Crowl, Understanding Explosions, Center for Chemical Process Safety (CCPS) of the American Institute of Chemical Engineers (AIChE) copyright 2003 AIChE and reproduced with permission. ]... 

When an ignition source is brought into contact with a flammable gas or mixture of gases, a combustion chemical reaction will occur at the point of introduction provided an oxidizer is present, normally oxygen. The combustion components are commonly referred to as a simple fire triangle ... 

Fire can only occur when all three of the above elements are present and in the proper conditions and proportions. These three basic conditions are often represented as a fire triangle shown in Figure B-1. The combustion reaction itself is often included as a fourth central element of the fire triangle. 

There are three basic theories that are used to describe the reaction known as fire. They are the fire triangle, the tetrahedron of fire, and the life cycle of fire. Of the three, the first is the oldest and best known, the second is accepted as more fully explaining the chemistry of fire, while the third is a more detailed version of the fire triangle. Each is briefly described below. 

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