Influence of Passageway Fires on Ventilation Flows.
Lee-CK; Hwang-CC; Singer-JM; Chaiken-RF
Mine Ventilation Congress Reno Nevada, 1979 Nov; :448-454
The influence of passageway fires on ventilation flows was investigated in three horizontal fire tunnels: (1) a laboratory- scale fire tunnel network, (2) a small-scale fire-plume tunnel, and (3) a laboratory-scale simulated mine gallery. Wood was used in the first and third tunnels and gas burners were used in the second tunnel to generate passageway fires. Experimental measurements included gas mass flow rate, velocity, temperature, and pressure on the passageways and exhaust fans. The effects of the fires were investigated by comparing the measurements obtained before and during the fires. Results show that a passageway fire essentially increases the flow resistances of the passageways of a tunnel flow network by virtue of volatile fuel mass injection and high combustion temperatures. The ventilation airflow rate is consequently throttled to lower values than that before the fire. At severe throttling, reverse flow occurs. Conditions for reverse flow are characterized by two froude numbers based on gas velocity and density upstream of the fire and height of the passageway.
Mine Ventilation Congress, Reno, Nevada, Nov. 4-8, 1979. Soc. Min. Eng. AIME, New York, 1980, Pp. 448-454