Fire Properties Of Solid, Liquid And Gases:
Conduction:
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Conduction is most clearly present in solid material.
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Heat is transferred from one atom to another atom without any movement
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Metals conducts heat energy easily and called as good conductors.
Convection:
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Light liquid goes up.
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Hot liquids goes up and cool liquids comes down.
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This circulation is called convection eg: Boiling water.
Radiation:
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Heat is transmitted neither by conduction nor by convection.
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This method of heat transmission is known as radiation
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Eg:- sun rays passes through the earth.
Physical Properties Of Fire:
(i) Flash point: Flash point is the lowest temperature at which vapors or gases form on the surface of the solvent and flash upon the application of an external source of ignition.
(ii) Fire point: Fire point is the lowest temperature at which the fire can occur.
(iii) Auto ignition temperature: This is the temperature at which flammable liquids or gases will be ignited on its own without the application of external ignition sources.
Hazardous properties of some flammable liquids:
Name | Flash pointC | Auto ignition temperatureC | Lower explosive limit% | Upper explosive limit% |
Acetaldehyde | -38 | 175 | 4.1 | 60 |
Acetone | 43 | 516 | 5.4 | 16 |
Ammonia | -18 | 465 | 2.6 | 12.8 |
n-Butane | -60 | 405 | 1.8 | 8.4 |
Kerosene | >38 | 210-300 | 0.7 | 6.0 |
Diesel | >38 | 177-329 | 1.3 | 6.0 |
Petrol | -46 | 371 | 1.3 | 7.6 |