Ventilatory shaft of the underground mine

VENTILATORY SHAFT OF THE UNDERGROUND MINE (EN: ventilation shaft, air shaft; DE: Ausziehschacht, Wetterschacht; FR: canar, puits d'entree d'air; ES: pozo de ventilacion; RU: вентиляционный ствол шахты) is the mine shaft, which is purposed mostly for the issuance and delivery of the air, which is used for the airing of the mine workings; the ventilatory shaft is usually the shaft with the outgoing stream of the air. The ventilatory shaft of the underground mine is sometimes also used for the lowering and lifting of the people and rock, for the lowering of the roof support materials (the ventilatory-auxiliary shaft), and of the stowing material (the ventilatory-stowing shaft). According to the direction of the movement of the stream of the air, they distinguish these ventilatory shafts of the underground mines: the delivering (injecting) shaft, where the fresh air from the surface enters into the mine workings; the issuing shaft, where the air from the mine workings rises onto the surface. The maximal acceptable speed for the movement of the air within the ventilatory shafts of the underground mines, which are not equipped with the permanently active lift, is 15 metres per second, while within the shafts, where is performed the lowering and liftin g of the people, the maximal speed of the air is 8 metres per second. As a rule, the ventilatory shaft of the underground mine has the circular shape, the internal diameter is 4-7 metres; the lining is made of the concrete. Less often (at the ore mines), they use the ventilatory shaft of the underground mine with the rectangular shape and the wooden lining. At the mouth of the ventilatory shaft of the underground mine (delivering), there are constructed the holes, through which this shaft is connected with the ventilatory channel. Within the ventilatory-auxiliary shaft, they sometimes lay the fixtures for the pipes for the water drainage, for the compressed air, and the cables.