Ventilation of the mine workings with the dead end

(Figure # 1) The airing of the mine workings with the dead end with the help of the ventilators for the local airing

VENTILATION OF THE MINE WORKINGS WITH THE DEAD END (EN: dead heading ventilation, ventilation line end; DE: Sonderbewetterung der nichtdurchgangigen Bauen; FR: ventilation des culs-de-sac, aerage des galeries en culs-de-sac; ES: ventilacion de los topes ciegos; RU: вентиляция тупиковых выработок) is the complex of the activities for the provision of the fresh air into the mine workings with the dead end within the underground mines. They perform the ventilation of the mine workings with the dead end with the help of the longitudinal bulkheads, of the ventilatory pipes, and of the parallel mine workings, on the account of the work of the ventilators for the local and main (the depression within the entire underground mine) airing.

The ventilation of the mine workings with the dead end, using the ventilators for the local airing, depending on the conditions for the penetration, is performed using the injecting, sucking, or combined methods. In case of the injecting method (see the Figure # 1, a), which is the most widespread method, and this method is the single method, which is acceptable at the underground mines, which are dangerous because of the gas, the ventilator (or several ventilators) are installed within the through-passage mine working for the delivery of the air, which is aired on the account of the depression within the entire underground mine. The air, which is injected by these ventilators, arrives through the ventilatory pipes into the space near to the stope within the mine working with the dead end.

The effective ventilation of the space near to the stope is ensured in case of the installation of the end of the pipe at the distance "l" of at most "4S" from the stope, where "S" is the area of the cross-section of the mine working. Because of the fact, that the outgoing stream passes throughout the entire mine working with the dead end, the ventilation should ensure the decrease for the concentration of the harmful gases to the acceptable norm at any point within the mine working. In case of the sucking method (see the Figure # 1, b), the ventilator for the local airing is installed within the through-passage mine working, which is aired on the account of the depression within the entire underground mine, and the end of the ventilatory pipe is installed into the zone of the stope within the mine working with the dead end. During the process of the work of the ventilator, the air, which is sucked from the space near to the stope, is issued into the through-passage mine working for the delivery of the air. The effective ventilation of the mine working near to the stope with the dead end is reached i n case of the "l = 0.5S" condition. The volume of the space, which is subject to ventilation, is comparatively small. The installation of the end of the pipe near to the stope within the mine working causes the necessity for the protection of this pipe during the conducting of the blasting works.

The combined method for the ventilation of the mine workings with the dead end combines within itself the advantages of the injecting and sucking methods for the ventilation. In this case, the sucking ventilator is considered the major ventilator; the amount of the air, which is entering into the sucking pipeline, must exceed by at least 30% the consumption of the auxiliary ventilator (injecting). In case of all the methods for the ventilation of the mine workings with the dead end using the ventilators for the local airing, their maximal performance, in case of the installation within the through-passage mine working, must amount to at most 30% of the amount of the air, which is passing through the mine working (on the account of the depression within the entire underground mine).

(Figure # 2) The airing of the mine workings with the dead end on the account of the depression within the entire underground mine

In case of the ventilation of the mine workings with the dead end using the ventilators for the main airing, the longitudinal bulkheads (see the Figure # 2, a) block the cross-section of the through-passage mine working, through which there is delivered the fresh air on the account of the depression within the entire underground mine, and also they divide the mine working with the dead end into two parts. Through one of these parts, the air arrives to the stope, and through the other part, the air is removed. The longitudinal bulkheads are made of the hinged panels, wooden boards, bricks, and other materials, and are grown during the advancement of the stope within the mine working with the dead end. They use these bulkheads, when there is required the large amount of the air for the ventilation of the mine workings with the dead end (with the length of up to 60 metres).

The ventilation of the mine workings with the dead end with the help of the ventilatory pipes (see the Figure # 2, b) is performed using the method for the blocking of the cross-section within the through-passage mine working for the delivery of the air using the bulkhead, through which there passes the ventilatory pipe, which is directed further into the stope within the mine working with the dead end. Because of the significant aerodynamic resistance of the pipes, which are passing through the bulkhead, this method is used for the ventilation of the short mine workings with the dead end. They use the ventilation with the usage of the parallel mine workings (see the Figure # 2, v) in case of the necessity for the delivery of the significant amounts of the air through the long distances. In this case, near to the major mine working, they penetrate the auxiliary mine working (mainly the mine workings for the useful minerals), and connect these mine workings together using the trans verse passages (with the intervals of at most 10-20 metres), or using the boreholes. During the penetration of the new transverse passage (borehole), the previous passage is blocked (and is hermetically sealed) using the bulkhead. Immediately into the stopes, the air is delivered with the help of the longitudinal bulkheads, ventilatory pipes, or ventilators. All the schemes for the ventilation of the mine workings with the dead end on the account of the depression within the entire underground mine, because of the continuity of the action of the ventilation, and because of the absence of the additional causes for the suction of the air within the mine working, distinguish themselves with the great reliability and safety.