CFD Studies on the Phenomenon of Gob Breathing Induced by Barometric Pressure Fluctuations

Details

• Personal Author:
  Bogin G Jr. ; Brune, Jürgen F. ; Gilmore R ; Grubb J ; Juganda A ; Lolon S ; Saki S
• Description:
  In longwall mines, atmospheric or barometric pressure fluctuations can disturb the pressure balance between the gob and the ventilated working area of the mine, resulting in a phenomenon known as "gob breathing". Gob breathing triggers a gas flow across the gob and the working areas and may result in a condition where a methane accumulation in the gob flows into the face area forming an explosive mixtures. This paper discusses results of Computational Fluid Dynamics (CFD) modeling carried out to analyze this phenomenon and its impact on the explosive mixture development under a bleeder-ventilated longwall gob panel scheme. Modeling results indicate that the gas inflow and outflow across the gob and the formation of Explosive Gas Zones (EGZs) are directly affected by the barometric pressure changes. Methane gas and EGZs in the gob expand out toward the face and bleeder entries during the falling barometric pressure. Where methane zones interface with mine air, EGZ fringes may form along the face and in the bleeder entries. When the atmospheric pressure increases, an ingression of oxygen into the gob is observed that can also increase EGZs in volume. The findings from this study help assess the methane ignition and explosion risks associated with fluctuating atmospheric pressures. [Description provided by NIOSH]
• Subjects:
  Explosions Methane Mining Occupational Health Safety
• Keywords:
  Atmospheric Pressure Explosive Gases Longwall Mining Methanes Mine Gases
• Publisher:
  Society for Mining, Metallurgy, and Exploration, Inc.
• Document Type:
  Text
• Funding:
  Contract
• Genre:
  Proceedings
• Place as Subject:
  Colorado ; OSHA Region 8
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-5
• NIOSHTIC Number:
  nn:20069153
• Citation:
  2016 SME Annual Meeting, February 21-24, 2016, Phoenix, Arizona, preprint 16-154. Englewood, CO: Society for Mining, Metallurgy, and Exploration, Inc., 2016 Feb; :1-5
• Federal Fiscal Year:
  2016
• Performing Organization:
  Trustees of the Colorado School of Mines
• Peer Reviewed:
  False
• Start Date:
  20140901
• Source Full Name:
  2016 SME Annual Meeting, February 21-24, 2016, Phoenix, Arizona, preprint 16-154
• End Date:
  20190831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:020ca5ee7eb896c4a4214e12e8452125fb3cbe1e2f3ee106cdeed7ed725b3c83b41a679c6428179f6d52c1a3ffa3468ae30d531bd19bfc628fb614f5d991f435
• Download URL:
  https://stacks.cdc.gov/view/cdc/207687/cdc_207687_DS1.pdf
• File Type:
  [PDF - 506.22 KB ]