Page 60 - Advanced Mine Ventilation
P. 60
Estimation of Ventilation Air 4
Quantity
Chapter Outline
4.1 The Modern Mine Layout 44
4.2 Methane Emissions 45
4.3 Mildly Gassy Coal Seams 48
4.3.1 Premining Degasification 48
4.3.2 Postmining Degasification 48
4.3.3 Ventilation Layout and Quantities 48
4.4 Moderately Gassy Coal Seams 49
4.4.1 Premining Degasification 49
4.4.2 Postmining Degasification 49
4.4.3 Ventilation Layout and Quantities 49
4.5 Very Gassy Coal Seams 49
4.5.1 Premining Degasification 49
4.5.2 Postmining Degasification 51
4.5.3 Ventilation Layout and Quantities 51
4.6 Limitations on the Longwall Face Width Owing to Face Methane
Emissions 51
4.6.1 Gas Emissions on Longwall Faces 52
4.6.2 Gas Layering on Longwall Faces 53
4.6.3 Mathematical Modeling of Methane Flow 53
4.7 Limitations on the Longwall Face Width Owing to Gob Methane
Emissions 54
4.7.1 Specific Emission of a Coal Seam 54
4.7.2 Specific Gob Emissions for the Coal Seam 54
4.8 Air Quantity Requirements for Development Headings 56
4.9 Estimation of Total Required Ventilation Air 56
4.9.1 Expansion of Air in Return Shafts 57
4.9.2 Air Velocities in Various Branches of a Coal Mine 57
4.10 Standards of Volumetric (Ventilation) Efficiency 58
Problems 59
References 59
Advanced Mine Ventilation. https://doi.org/10.1016/B978-0-08-100457-9.00004-3
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