Dust-settling method of working face for layered and fully-mechanized coal mining of gently-declined thick coal seam by water injection under dynamic pressure

Abstract

The invention discloses a dust-settling method of a working face for layered and fully-mechanized coal mining of a gently-declined thick coal seam by water injection under dynamic pressure. The methodcomprises the following steps of drilling a sealing-tape machine crossheading and an air return crossheading in the two sides of the coal seam respectively, and getting through and connecting the tail ends of the sealing-tape machine crossheading and the air return crossheading to form the working face used for fully-mechanized coal mining; conducting drilling at intervals in the sealing-tape machine crossheading and the air return crossheading in the length direction of the sealing-tape machine crossheading and the air return crossheading to drill out spaced dynamic pressure holes I, and filling the dynamic pressure holes I with cut-off devices I used for sealing the radial direction of the dynamic pressure holes I; injecting safe gas in the dynamic pressure holes I through the cut-off devices I according to a predetermined exhaust rule, and then replacing hazardous gas in the dynamic pressure holes I with the safe gas through the cut-off devices I; using the safe gas to sufficientlyopen up the intervals according to the predetermined exhaust principle to avoid the situation that the hazardous gas drifts away, causing decompression and accompanying compaction effect; and meanwhile, the hazardous gas and safe gas are mixed to constantly and continuously dilute the concentration of the hazardous gas, and therefore, the aggregation effect of the hazardous gas is reduced to a great extent.

Description

technical field [0001] The invention relates to the technical field of mine safety mining, in particular to a method for dynamic pressure water injection and dust reduction on working faces of fully mechanized layered mining of gently inclined thick coal seams. Background technique [0002] In order to solve the problem of large coal dust in the fully mechanized mining face of the hard roof in the thick coal seam, the traditional method is to install the belt conveyor along the trough and the return air trough of the fully mechanized mining face on the thick coal seam along the parallel working face in the coal seam. In the pre-drainage coal seam, the gas pressure is relieved in advance, and the gas extraction pipe is used as the water injection pipe for static pressure water injection. [0003] That is to say, the method of pumping and discharging the gas, but this method has disadvantages: [0004] 1. Bring compaction effect, compaction effect: when drilling holes for gas...

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Problems solved by technology

[0006] 3. Aggregation effect, the way of pumping and drainage concentrates the gas in the coal seam, thereby increasing the concentration of gas in the air, resulting in local gas accumulation that poses a safety threat

[0007] And the dust on the working face increases with the increase of the mining intensity. In addition to the water spraying and dust reduction during the normal coal cutting of the shearer, the coal wall breaks and falls when the water content of the coal seam is less than 4% and the thick coal seam is fully mechanized. coal dust, it is difficult to achieve the effect of dust reduction by watering with the usual shearer, and there are disadvantages:

[0008] 4. Traditional static pressure water injection cannot effectively infiltrate wet coal seams due to the above-mentioned problems of small pores and low permeability

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