Effects of stratification on carbon monoxide levels from mine fires.
Proceedings of the 6th US mine ventilation symposium, June 21-23, 1993, Salt Lake City, Utah. Bhaskar R, ed. Littleton, CO: Society for Mining, Metallurgy, and Exploration, 1993 Jun; :489-494
This report describes the results of research conducted in the Bureau of Mines Experimental Mine at Lake Lynn Laboratory to determine the effects of air velocity, sensor spacing, and stratification of CO levels on the detection of slowly-developing coal/conveyor belt fires. In general, the time to detect a developing fire is calculated assuming an average CO level that has mixed completely with the ventilated airflow. The data indicate that CO sensors placed near the roof of an entry take advantage of buoyant-induced stratification of combustion products, resulting in earlier detection of developing fires. Even during the low-temperature, smoldering stage of a fire, the combustion products will tend to stratify near the roof, and once flaming occurs, the degree of stratification increases markedly. As one would expect at higher air velocities, the degree of stratification is less than at lower air velocities, although still significant especially during the flaming stages of the fire.
Mining-industry; Underground-mining; Mine-fires; Monitoring-systems; Detectors
Proceedings of the 6th US mine ventilation symposium, June 21-23, 1993, Salt Lake City, Utah