A History of Research and a Review of Recent Developments

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Propellant, dust, gas and vapour
and subsequently to the use of flickering oil lamps and carbide lamps. To help
search for accumulations of methane gas, which is odourless and tasteless,
the miners once took canaries underground, but more sophisticated gas detectors
have been introduced over the years. These included a permissible flame safety
lamp that would not become hot enough to ignite gas, but which would burn
with a blue cap above the yellow flame if gas were present. The best answer to
the gas hazard in mines is an efficient ventilation system, and most mines
have a carefully planned system of passages, ducts, fans and air blowers to
ensure that gases are diluted and driven out.
The accumulation of methane is not confined to coal workings, of course,
and there have been examples of methane explosions in civil engineering
Table 3.1 Explosion pressures and rates of pressure rise of
dusts, powders and particles