Changes in Air Temperature and Flow Rate During A Mine Fire in A Roadway

This paper describes the results of mine fire experiments conducted in actual size, both in level and inclined galleries. The objectives of the experiments are to obtain the fundamental data about air temperature distribution downwind of fire and back flow speed of heated air containing toxic gases from the fire. These data are indispensable for taking effective counter measures against mine fire. Several gas concentrations in air from the fire, ventilation air speed change and pressure drop over the fire zone are also measured. The air temperatures decrease almost exponentially with distance from the fire. A coefficient to express the air temperature decrease is determined by the experiments. The apparent dependence of the coefficient on time was not observed by these experiments. The ventilation air speed decreases as the fire develops. The higher the temperature of the fire zone and the initial air speed, the greater is the decrease in air velocity. The back flow speed of air near the roof of the roadway was observed when the ventilation air speed is less than 1.5 m/s in the level roadway and 1.7 m/s in the downward ventilated inclined roadway.