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FIRE AND ITS TERMS

CONTENTS

1. What is Combustion?
 

2. What is Fire?

3. Fire as a Matter or Energy?

 

4. Terms related to Fire.

1. COMBUSTION -

Combustion is a chemical process of oxidation accompanied by evolution of heat.

There are three types of combustion process.

  1. Slow Combustion : It is a chemical reaction accompanied by slow evolution of heat but bot by light. (Eg. Burning of wood).

  2. Rapid Combustion : It is a chemical reaction accompanied by rapid evolution of heat and a very small amount of light. (Eg. Petroleum products).

  3. Spontaneous Combustion : It is a chemical reaction occuring as a result of heat by the absorption of atmospheric oxygen at ordinary temperature, without the application of external heat. (Eg. Lignite dust).

2. FIRE -

Fire : It is a rapid combustion resulting in release of heat and light of flame.

Flame : It is luminous, hot zone of the fire.

Hotspot : It is a spot where fire ignite or start or begin.

Smoke : It is a suspension of fine particles of solid in air produced during the burning of a substance, generally black to white in colour, consists of soot, ash and other solid particles.

Soot : It is a mass of impure carbon particles resulting from the incomplete combustion of hydrocarbons.

Ash : It is a solid remains of fire. Ashes are the end products of the fire which results due to incomplete combustion of materials.

3. FIRE AS A MATTER OR ENERGY -

Matter is anything that has mass and volume which occupies space.

Flame consists of gases which contains vaporized fuel, oxygen, carbon dioxide, carbon monoxide, water vapour, and nitrogen. Hence it is a MATTER.

Heat and light produced in burning is an ENERGY.

Thus, FIRE is both a MATTER as it occupies space and is a mixture of gases and vapours and ENERGY in the form of radiation, light and heat.

NOTE : Fire upon burning always releases heat, light, smoke, various gases and soot.

4. TERMS AND DEFINITIONS -

Fire : It is an active rapid burning and oxidation process accompanied by heat, light and poisonous gases or smoke due to combustion.

Flame : It is a visible luminous, hot zone gaseous part of the fire.

Hotspot : It is a spot where fire ignite or start or begin.

Smoke : It is a suspension of fine particles of solid in air produced during the burning of a substance, generally black to white in colour, consists of soot, ash and other solid particles.

Soot : It is a mass of impure carbon particles resulting from the incomplete combustion of hydrocarbons.

Ash : It is a solid remains of fire.

Fume : It is an unpleasant and unhealthy smoke and gases which are produced by fires.

Ignite : It is to set fire or to begin fire or catching of fire.

Ignition : It is beginning of fire or start of fire.

Ignition Temperature : It is a temperature at which the combustible material ignites.

Self or Spontaneous Ignition : It is an ignition without an application of external flame or igniter.

Spontaneous Ignition Temperature : It is a temperature at which combustible material get ignited without an application of external flame or igniter.

Flash Point : It is a temperature at which combustible material gives off enough vapour in the vicinity to initiate ignition on application of external flame or igniter.

Fire Point : It is a lowest temperature at which vapours above a liquid will continue to burn once ignited. Fire point is always higher than the flash point.

Auto - Oxidation : It is a process of slow oxidation with accompanying evolution of heat, sometimes leading to auto-ignition if the energy is not removed from the system.

Flammability Limits : It is a mixture of dispersed combustible materials and oxygen in the air which will burn only if the fuel concentration lies within well defined lower and upper bound determined experimentally.

  • Lower Flammability Limit (LFL) : It is the lowest concentration or percentage of a gas or a vapour in air which is capable of producing a flash of fire in the presence of an ignition source. Concentrations lower than LFL are "too lean" to burn.

  • Upper Flammability Limit (UFL) : It is the highest concentration or percentage of a gas or a vapour in air which is capable of producing a flash of fire in the presence of an ignition source. Concentrations higher than UFL are "too rich" to burn.

Fire Extinction : It is putting off of the fire.

Fire Fighting : It is an action of putting off of the fire.

Fire Prevention : It is preventing the occurrence of fires by prior actions or precautions and provisions.

Fire Backdraft : It ia a rapid or explosive burning of superheated gases in a fire, caused when oxygen rapidly enters an oxygen-depleted environment.

Video -

To view above content in video, click the video below to watch on You Tube channel @Sonartive EduHub.

REFERENCES

1. Industrial Safety, Health and Environment Management Systems - by R. K. Jain and Sunil S. Rao.
 

2. Wikipedia.

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