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Starvation                                         Limitation or removal of fuel from the scene of fire is known as starvation. The extinction of fire by  starvation is applied in three ways.By removing combustible materiel from the neighbor hood of the fire. By removing the  fire from the neighbor hood of combustible material By subdividing the burning material.The smallest fire produced may be left to burnout easily rather than extinguishing . Cooling                                       limitation or removal of heat from the scene of fire is known as cooling. If the rate at which heat is generated by combustion  is less than the rate at which  it is dispersed  through  various agencies, the combustion cannot survive. There for the first...

Elements of fire.  It has been shown from the rectangle from combustion that four factors are essential to combustionnamely:     1, The presence of combustiable substance (fuel) . 2,The presence of oxygen . 3, The attainnment & maintenance of  a certain minimum temperature(heat) . 4, The chain reaction of flame.   Methods of extinguishment. If one or more of these elements is limited ,the fire can be extinguished. the methods of extinguishing fire may there fore be classified as follows:  *Starvation  * Smothering  *Coolinng   *Inhibiting

Convection:                                                It is ocures only in liquids and gasses.When liquid or gas is heated it expand & becomes less dense. The lighter fluid raises up and the colder liquids which is denser goes down. Thus a circulation is set up in the fire situation in a building convection currents can convey hot gasses produced by combustion through stairwells and open lift shafts there by spreading fire to the upper part of a building .As the hot gasses rise up , cold which is denser will move down towards fire and accelerate burning.  Radiation:                               ...

Heat travels from regions of high temperature to regions of lower temperature. There are three methods by which heat may be transmitted. They are :  *Conduction *Convection *Radiation. Conduction :                        Conduction may occur in solid ,liquids or gasses ,although it is most clearly present in solids. In conduction heat energy is passed on from one molecule to another. The molecules vibrate about a mean position and pass on heat energy by colliding with their neighbors. The ability to conduct heat vapors from one materiel to another.Most of the materiel conduct heat easily and are classed as Good conductors.                                         ...

Critical temperature : It is the highest temperature ,above which a gas cannot be liquified by the increase of pressure alone.Critical temperature of CO2 is 31.35c . Critical pressure : The pressure rquierd to liquefy a gas at its critical temperature is called the critical pressure> The critical pressure of CO2 is 73.1 bar.    Sublimation : The change of state from solid directly to gas is known as sublimation.

Fire is an oxidization process of combustible materiel in the presence of heat , the requirement of heat for different materials differs with their physical nature . combustion will occur or continue only with the attainment of the required temperature. Hence it become necessary to know the flash point,fire point,spontaneous ignition temperature of a substance.   Flash point : It is the lowest temperature at which there is sufficient vaporization of the substance produce   a vapor which will flash momentarily when a flame is applied.  Fire point:   It is the lowest temperature at which the heat from the combustion of a burning vapor is capable of producing sufficient vapor to enable combustion to continue.  Spontaneous ignition temperature: It is the lowest temperature at which the substance will burn with out the introduction of a flame or other ignition source .This implies that under certain conditions some materials undergo spontaneous ignition.

                                  The further research about fire determined that a fourth factor  that is , a chemical chain reaction is a necessary component of a fire. Fire triangle was changed to a fire tetrahedron  to reflect this fourth element. A tetrahedron can be described as a solid  having four plane faces .Essential all for element must be present for fire to occur .Removal of any one of these essential elements will result in the fire being extinguished. The four elements are: Oxygen: To sustain combustion (14 to 21% ) sufficient.  Heat: To raise the material to its ignition temperature. Fuel or Combustible material. Chain reaction: Subsequently an exothermic chemical chain reaction .                 ...