RI 8310 Jet Fan Effectiveness as Measured With SF6 Tracer Gas

The Bureau of Mines conducted tests using a tracer-gas technique to measure the effectiveness of the jet fan, which is often employed in mines to ventilate dead headings. Results of these tests show that jet fans can (1) ventilate dead headings beyond the maximum penetration distance indicated by smoke-tube detection of air movement, and (2) redistribute available fresh air through larger working areas. However, if the fresh air base is insufficient, the fan will merely recirculate the contaminated air and disperse it over a larger volume.