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Airflow distribution patterns at a longwall mine depicted by CFD analysis and calibrated by a tracer gas field study.

Authors
Krog-RB; Schatzel-SJ; Dougherty-HN
Source
SME Annual Meeting & Exhibit and CMA 113th National Western Mining Conference 2011, 28 February - 2 March 2011, Denver, Colorado, USA. Littleton, CO: Society for Mining, Metallurgy, and Exploration, Inc., 2011 Aug; :384-389
NIOSHTIC No.
20040391
Abstract
Airflow patterns in longwall bleeder systems are affected by gob permeability and porosity and the condition of the gateroad entries after mining. As longwall panels are mined, areas of the caved zone and portions of the remaining gateroad entries become inaccessible, making direct ventilation measurement impossible. Mine operators are left to estimate direction and amount of airflow in the gob and the surrounding gateroads. The most readily available locations are where air enters the worked-out area, approved measurement point locations (MPLs) and/or evaluation points such as bleeder evaluation points, intake evaluation points, and the outer bleeder entry. Ventilation models (network or Computational Fluid Dynamics, CFD) can model the gob and the surrounding bleeder system but calibrating these models is difficult without field data. NIOSH installed a tube sampling system ahead of a longwall face and, as the face retreated, released a slug of tracer gas (SF6) to determine transportation times and flow rates in the inaccessible gateroads. The data was used to calibrate both network and CFD ventilation models for a longwall panel. Both model types were used to predict the airflow patterns in the gob and to determine the airflow rate from the longwall tailgate corner back to the bleeders.
Keywords
Mining-industry; Air-flow; Air-monitoring; Air-quality; Air-quality-measurement; Air-samples; Mine-workers; Ventilation; Underground-mining; Longwall-mining
Publication Date
20110801
Document Type
Conference/Symposia Proceedings
Fiscal Year
2011
NTIS Accession No.
NTIS Price
ISBN No.
9781617829727
NIOSH Division
OMSHR
Source Name
SME Annual Meeting & Exhibit and CMA 113th National Western Mining Conference 2011, 28 February - 2 March 2011, Denver, Colorado, USA
State
PA; CO
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