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7 The Role of Ventilation in Fires and Explosions
Fig. 7.1 Fire triangle
Combustible
material
Activation
energy
Fire
Oxidizing
agent
The activation energy sources for fires are included in European Standard EN 11271:2012, and they are:
1. Hot surfaces;
2. Flames and hot gases;
3. Mechanical sparks;
4. Electrical material;
5. Eddy currents, cathodic corrosion protection;
6. Static electricity;
7. Lightning strikes–some of them can be directly transmited into underground
mines or cause fires in the exterior that may end up in the interior;
8. Electromagnetic fields in the range 9 kHz–300 GHz;
9. Electromagnetic radiation in the range 300 GHz to 3 × 10
16 Hz or wavelengths
from 1000 to 0.1 μm (optical spectrum range);
10. Ionizing radiation;
11. Ultrasounds;
12. Adiabatic compression, shock waves, circulating gases; and
13. Chemical reactions.
Of the above, historically the commonest sources of fires in mines have been (Stracher
and Taylor 2004):
• Soldering and welding,
• Cutting works,
• Electrical apparatus, and
• Explosives.