| Attaining an accurate understanding of airflow distribution at the continuous miner face is instrumental in maintaining a safe mining environment. Currently, continuous miner face air readings can be taken in the last open crosscut and at the curtain mouth. By measuring airflow in a pre-determined area it is accepted that an adequate quantity of that air sweeps the face of harmful dust and gasses. Unfortunately, due to the location inaccessibility, precise face velocity readings can only be determined in a laboratory setting or through computer-simulated programs verified by laboratory models. The National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) ventilation gallery was used to simulate common ventilation scenarios and measure air velocities utilizing ultrasonic anemometers. The ventilation gallery simulates a full-scale mining face similar to a continuous miner (CM) room and pillar operation and provides a means to obtain representative air velocities in areas typically inaccessible on an actual CM face. Methane gas was also released from pipes located at the face to simulate realistic face gas emissions and dilutions.;Improving upon previous empty gallery testing and to more effectively determine representative face methane readings, a mockup of a continuous miner with water sprays and a scrubber fan was used to further refine face airflow conditions that would be closer to actual mining conditions. Throughout testing, methane was monitored along the face and at the machine-mounted monitor location allowing direct comparisons of concentrations at these critical locations. Multiple laboratory tests were run, varying parameters such as airflow quantity, entry width (sump or slab cut), and face ventilation configuration (blowing or exhausting curtain). Test data showed a similar pattern of methane concentrations at both low and high airflow quantities, but a difference in the distribution of methane concentrations between narrow and wide entry widths. As verified in previous research, most tests showed that blowing face ventilation was more efficient in diluting methane than exhausting ventilation. The patterns of airflow and methane concentrations observed in this testing can further improve the understanding of airflow in and around the CM and face, promoting effective use of face ventilation to improve the health and safety of miner. |
