Fire Engineering - Chapter 04. Fire

1) Definition of Fire

A process in which substances combine chemically with oxygen from the air and typically give out bright light, heat and smoke that is call of FIRE.

2) Triangle of Fire

3) Tetrahedron of Fire

In a fire there are two different phase in which combustion proceeds, ‘surface combustion mode and flaming mode’.

The surface combustion mode incorporates the three essential elements of fire as represented by the triangle of fire – Heat, Oxygen and combustible material.

The flaming mode incorporates four basic requirement- heat, oxygen, combustible material and uninhibited chain reaction of combustion process. This is called the tetrahedron of fire.

4) Classification of Fire

Class ‘A’- Solid Fire

Example: Paper, Wood, Cloth, etc

Class ‘B’- Liquid Fire

Example: Oils, Paints, Chemicals, Wax, etc.

Class ‘C’- Gases Fire

Examples: L.P.G., Acetylene, Hydrogen, Methane, Natural Gas, etc

Class ‘D’- Metal Fire

Examples: Magnesium, Sodium, Uranium, Thorium, etc

Class ‘E’- Electrical Fire

Examples: Electronics equipment

Class ‘K’- Kitchen Fire

Examples: cooking oils, LPG cylinder, and Kitchen equipment fire.

5) Types of Extinguishing Media or Agents.

Water type Fire Extinguisher

For Class ‘A’ Fire

BC Dry Chemical Fire Extinguisher

For Class ‘B’ and ‘C’ Fire

Foam type Fire Extinguisher

For Class ‘B’ Fire

Carbon Dioxide (Co2) type Fire Extinguisher

For Class ‘B’ and ‘C’ Fire

ABC type Multipurpose Fire Extinguisher

For Class ‘A’, ‘B’ and ‘C’ Fire

Dry Powder Fire Extinguisher

For Class ‘D’ Fire

Wet Chemical

For Class ‘K’ Fire