EXPERIMENTAL STUDY ON WATER SPRAY ZONES FOR SUPPRESSION OF MINE FIRE SPREADING.

A series of full-scale fire experiments were carried out to establish a standard for the installation of the water spray zone in timbered roadways. Following theoretical studies and comparative tests with timber lining the decision was taken to use cribs of wood as the fuel, instead of the timber lining. Based on this result, the quantity of water required to extinguish the fire was measured, varying the ventilation velocity from one to seven metres per second in the full-scale 400 m test gallery with cross section of 5. 4 m**2. In the case of an air velocity up to three metres per second, there is an approximately linear relationship between the required water quantity and the ventilation velocity. But this tendency is not necessarily present in the case of a higher air velocity of more than three metres per second. A numerical model simulation results agree well with the experimental results in an air velocity range of up to three metres per second.