Method for preventing gas from being accumulated at corners on coal faces

Abstract

The invention relates to a method for preventing gas from being accumulated at corners on coal faces. A process tunnel is added on the basis of an original 'U'-shaped mining gateway, and is placed at the top of a coal seam, and is close to the inner side of a return airway and parallel to the return airway and an intake airway, and the intake airway is respectively communicated with the return airway and the process tunnel via working surfaces so as to form two 'U'-shaped ventilating channels; and the process tunnel not only can realize total negative-pressure ventilation, but also realizes local fan ventilation. A drill site is further arranged in the process tunnel, gas is extracted, and water or stopping liquid is injected into the coal seam. The process tunnel is added on the basis of the original 'U'-shaped mining gateway to form the double 'U'-shaped ventilating channels, return air of the original return airway is divided, and accumulation of gas at corners on a return air area is avoided; and the drill site further can be arranged in the process tunnel to extract gas of the coal seam, an adjacent layer and a worked-out section, or the water or stopping liquid is injected into the coal seam, the purposes of dust fall and fire prevention are achieved, and production is not affected.

Description

technical field [0001] The invention relates to a coal mining technology, in particular to a method for preventing gas accumulation at the upper corner of a coal mining working face. Background technique [0002] In coal mining, it is necessary to maintain the smooth ventilation of the mining roadway to ensure the safety of the construction and the dilution and discharge of gas at the upper corner of the coal mining face. Gas accumulation in the upper corner refers to the existence of a volume greater than 0.5m in the upper corner of the return air area. 3 The phenomenon that the gas concentration accumulated in the space reaches or exceeds 2%. The reasons for the accumulation are as follows: First, the upper corner of the coal mining face is the air leakage outlet of the goaf, and the air leakage in the goaf will bring out a large amount of high-concentration gas; second, the upper corner of the coal mining face is the wind flow The vortex area is not conducive to the tim...

AI Technical Summary

Problems solved by technology

Because the gas is discharged to the gas discharge lane, the gas concentration in the gas discharge lane often exceeds the limit, which is difficult to control; at the same time, because the gas discharge lane uses the return air of the goaf, it is easy to cause spontaneous combustion of coal in the goaf

The "Y" type mining roadway structure also has a large number of applications, such as image 3 As shown in Fig. 1, a roadway close to the upper coal pillar is reserved in the goaf as a return airway, which can effectively prevent the accumulation of gas in the upper corner, but due to the serious air leakage to the goaf, it is easy to cause spontaneous combustion of coal in the goaf

There is also a "W" type recovery roadway structure, in which an air inlet roadway is opened in the middle of the coal seam, such as Figure 4 As shown, this situation only makes the air leakage range of the goaf smaller, but there is gas in the upper and lower corners, and the improvement is not very useful

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