Studying Longwall Ventilation with Physical Modeling

Details

• Personal Author:
  Addis J ; Gangrade V ; Harteis, Samuel P.
• Description:
  Ventilation is the primary method for controlling gas and dust during longwall mining. It is not only important for controlling dust particulates, but also for maintaining permissible levels of methane. Historically, most methane-related mining disasters occurred or originated at or near the active production or development faces. More recently, methane ignitions and explosions have occurred in mines using the longwall mining method. Therefore, designing and maintaining an efficient ventilation system for a longwall mine is of utmost importance for mine operators. However, the complex and dynamic nature of coal mine ventilation systems makes it difficult to conduct accurate and detailed field assessments. To study longwall ventilation in a controlled environment, researchers from the National Institute for Occupational Safety and Health (NIOSH) built a unique physical model called the Longwall Instrumented Aerodynamic Model (LIAM) in a laboratory on the Pittsburgh Mining Research Division (PMRD) campus. In addition to its research applications, LIAM also serves as a dynamic tool for demonstrating longwall ventilation to mining industry stakeholders and the research community. This article discusses the development, applications and findings from LIAM. LIAM is a 1:30th scale physical model geometrically designed to simulate a single longwall panel with a three-entry headgate and tailgate configuration, along with three back bleeder entries (See Figure 1). It has a footprint of 8.94 m (29 ft) by 4.88 m (16 ft). The longwall face length in LIAM is 7.31 m (24 ft), which represents a 220-m (720-ft) longwall face in full scale. In LIAM's current setup, the gob is not "squared up," meaning the width of the gob is less than the length of the gob. This configuration allows researchers to study the near-face airflow characteristics in greater detail. The concept of physical modeling has been applied widely in industrial and environmental fluid flow studies, especially in the aeronautics, automotive and construction industries. In mining, however, the complex and dynamic nature of underground mines has made modeling studies more complicated and difficult when studying ventilation problems. Two particular challenges in developing a physical model include geometric and aerodynamic scaling. [Description provided by NIOSH]
• Subjects:
  Dust Explosions Methane Mining Occupational Health Particulate Matter Safety Ventilation
• Keywords:
  Coal Mines Dust Control Dusts Explosive Dusts Explosive Gases Gases Ignition Sources Longwall Mining Methane Control Methanes Models Particulates Underground Mines

  More +
• Series:
  Mining Publications
• ISSN:
  1091-0646
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; Pennsylvania
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  PMRD - Pittsburgh Mining Research Division
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  38-39
• Volume:
  123
• Issue:
  6
• NIOSHTIC Number:
  nn:20054523
• Citation:
  Coal Age 2018 Jul-Aug; 123(6):38-39
• Email:
  vgangrade@cdc.gov
• CAS Registry Number:
  Methane (CAS RN 74-82-8)
• Federal Fiscal Year:
  2018
• Peer Reviewed:
  False
• Source Full Name:
  Coal Age
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:d1825095344c33a43abcf5017f57362d76413482cff74e074c95339c15f2735489a80f661a2b891e4e8f850943a134c7502e3e0c438ccf889b78272cf669edcb
• Download URL:
  https://stacks.cdc.gov/view/cdc/227805/cdc_227805_DS1.pdf
• File Type:
  [PDF - 560.77 KB ]