Page 421 - Advanced Mine Ventilation
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390 Advanced Mine Ventilation
Figure 23.6 Variation of minimum ignition energy and minimum explosive concentration with
particle size (atomized aluminum dust) at 25 C at 1 atm.
The thicker the layer of coal dust, the lower is the ignition temperature [2]. The min-
imum ignition temperature for coal dust layer is 155 C. It is related to the logarithm of
the depth of layer, l, between 2.9 and 59.0 mm.
Table 23.7 Ignition Temperatures for Coals
Ignition Temperature (8C)
3
Combustible Dust Layer Cloud MEC (g/m )
Lignite, North Dakota 180 440 45
Coal, Wyoming (HVC) 180 575 40
Coal, Bituminous Colorado (HVC) 180 440 45
Coal, Bituminous Illinois (HVC) 160 600 40
Coal, Bituminous Pennsylvania (HVA) 170 610 55
Coal, low-volatile West Virginia 220 640 60
MEC, minimum explosive concentration.
