Determination of the most favorable location of the zero depression zone for injection and suction ventilation of mines

Abstract

Many ore mines that have an active aerodynamic connection of underground workings with the surface through the caving zone are ventilated by the injection-suction method. In this method, by regulating the operation of the suction and discharge fan, it is possible to create in the area adjacent to the caving, the so-called zone of zero depression. In this zone, the effective depression is extremely low, so there should be neither air suction from the surface nor air escape from the mine to the surface. The actual large size of the caving area and the occurrence of local natural draughts do not allow for the complete elimination of air movement through the caving. Air may move upward in one part of the caving and downward in another, but in much smaller quantities than with a single fan. Thus, the zero-depression zone created by the blower-suction method of ventilation serves as a measure to control air suction through the caving zone. At mines in the northern regions, the position of the zero depression zone plays an important role in improving the atmospheric conditions of these mines, reducing the entry of cold air from the surface ...