Page 76 - Advanced Mine Ventilation

Estimation of Ventilation Air Quantity 59

Problems

4.1 If a longwall face is 8 ft wide and emits 300 cfm methane, calculate the ventilation air neces-
sary to avoid gas layering. The seam is 6 ft high. Check if the methane concentration will be
below 1%.
4.2 Estimate the total ventilation air needed for a mine twice the size of the mine in Fig. 4.1.Ifa
single intake shaft is used, what would be its size to keep the velocity of air below 2000 ft/
min?
4.3 Calculate the optimum spacing of gob wells on a 1200-ft-wide longwall panel in a moder-
ately gassy mine. Create a graph similar to Fig. 4.10. Specific gob emission is 8 MMCF/
acre. Use 8-inch gob wells producing 2 MMCFD/well.

References

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Mutmansky J, editor. 11 U.S. Mine Ventilation Symposium. University Park, PA, USA:
Penn State University; 2006. p. 433e7.
[2] Thakur PC. Methane drainage from gassy mines d a global review. In: Proceedings of the
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6 International Mine Ventilation Congress; 1997. p. 415e22.
[3] Schatzel S, et al. Methane sources and emissions on the longwall panels in VA. In: Annual
Pittsburgh Coal Conference; 1992. p. 991e8.
[4] Thakur PC. Advanced reservoir and production engineering for coal bed methane. Elsevier
Publishing; 2016. p. 216.
[5] Kissell FN, Beilica RJ. An in-situ diffusion parameter for the Pittsburgh and Pocahontas #3
coalbed. USBM Research Report 7668. 1972.
[6] Leeming JR, Yates CP. Current British practice for methane ignition prevention in coal
mine headings. In: DeSouza E, editor. Proceedings of the U.S. Mine Ventilation
Symposium. Balkema Publishers; 2002. p. 487e96.
[7] Thakur PC. Mathematical modelling of tunnel air pollution. In: Pattison HC, editor.
Proceedings of the Rapid Excavation and Tunneling Conference; 1974. p. 283e94.
[8] Thakur PC. Optimum width of longwall panels in northern Appalachian basin, USA. In:
U.S. Longwall Symposium, Pittsburgh, PA; June 2015.
[9] Thakur PC. Optimum width of longwall faces in highly gassy coal mines e Part II. In: The
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12 U.S. Mine Ventilation Symposium. Reno, Nevada, USA: University of Nevada; 2008.
p. 81e6.
[10] Parsall BR. In: Roberts A, editor. Ventilation planning, mine ventilation. Cleaver Hume
Press Ltd; 1980. p. 244e62.