Safety of Reversing Air Flow in the Ventilation Shafts of the Mines in the Cold Season in the Absence of Heating

Modern mining enterprises engaged in development of the minerals are located in the regions of different conditions including in the regions of the Far North. For reducing the capital and operating costs, the management of these enterprises strives to optimize the technological processes for the raw materials extraction. These processes include ventilation of the underground mines. One of the ways to reduce capital costs in the mines with a flanking ventilation system is not to use the air heaters on the ventilation shafts due to their remoteness from the main industrial site of the mine and air supply shafts. In emergency conditions, when it is required to reverse the ventilation stream, the situations may arise when cold air starts flowing into the underground workings of the mine. The effect of negative temperatures of the air stream during reversal can have negative consequences associated with disruption of the operation of technological equipment, support of the ventilation shafts, and, also, affect the well-being and health of the miners during their evacuation. In this regard, it is required to conduct research on the thermophysical processes arising from the reversal of the ventilation stream, and to develop the appropriate preventive measures. The results of a study of the reverse mode of the mine ventilation in cold season in the absence of heating of the air stream entering the ventilation shaft are presented. Mathematical modeling was performed concerning change in the air temperature in the mine workings during reversal using AeroSet program. The main hazardous factors affecting the reversal of the air stream are highlighted, and the required measures are proposed aimed at compensating the negative consequences of the effect of cold air on the support and equipment in the shaft during ventilation.