Ventilatory borehole

VENTILATORY BOREHOLE (EN: ventilation hole, air hole; DE: Wetterbohrloch; FR: trou d'aerage; ES: orificio de ventilacion; RU: вентиляционная скважина) is the borehole with the large diameter, which is purposed for the ventilation; this borehole is used for the removal of the outgoing stream of the air, less often for the supply of the fresh air. At the underground mines, which are active, or are being reconstructed, the ventilatory boreholes are used for the improvement of the effectiveness of the airing for the chambers, for the long mine workings with the dead ends, for the excavation places, for the wings of the mine field, for the panels, blocks, layers, and underground mines as a whole. During the period of the construction of the large deep underground mines (for the decreasing of the time of the construction), the ventilatory boreholes are used for the creation of the through stream of the air on the horizon of the pit bottom. Within the USSR, the ventilatory boreholes have got the broad distribution at the underground mines within the Donets basin. The inner diameter of the ventilatory borehole is 0.78-3.2 metres, the depth is up to 1000 metres. There is practiced the drilling of the group of the ventilatory boreholes, which are situated in parallel, and are connected to one ventilator. In case of the diameter of more than 2 metres, the ventilatory boreholes are equipped with the cage lift, and are used as the emergency exits from the underground mines. The effective field for the usage of the ventilatory borehole is determined by the technical-economical comparison with the variant of the airing using the vertical shafts with the minimal diameter of 5 metres.