Device and method for large-diameter horizontal borehole bridging goaf gas extraction

Abstract

The invention relates to a device and method for large-diameter horizontal borehole bridging goaf gas extraction, and belongs to the technical field of coal mine gas safety. The device comprises a casing, a butterfly valve, a three-way joint and a pumping pipe. The butterfly valve is mounted on the casing, and the casing is connected to the pumping pipe through the three-way joint; the casing is placed inside a horizontal borehole; the horizontal borehole is formed in a coal pillar between a belt transporting crossheading of the working face and an air inlet duct of the adjacent working face and penetrates the coal pillar; a device for determining the flow rate, the temperature and the gas and carbon monoxide gas concentration is installed on the pumping pipe to monitor the gas extractionin a horizontal borehole bridging goaf. The device and method solve the difficulty in gas control of the return air corner on the high-strength working face under the condition of the 'Y' type ventilation mode, achieves multiple-point continuous controllable pumping of the gas in the goaf and monitors spontaneous combustion of the residual coal in the goaf in real time while effectively controlling corner gas emission.

Description

technical field [0001] The invention belongs to the technical field of coal mine safety, and relates to a device and a method for gas drainage in a large-diameter horizontal drilling bridging a goaf. Background technique [0002] The adjustable and controllable gas extraction volume in the goaf and the real-time monitoring of the marked gas are important guarantees for effectively controlling the spontaneous combustion of residual coal in the goaf and preventing the gas concentration in the upper corner of the underground mining working face from exceeding the limit. At present, the main mining coal seams of most high gassy mines in the northeast margin of the Ordos Basin in my country belong to the second type of spontaneous combustion coal seams, and the ignition period is 4 to 6 months. And the air intake of the fully mechanized coal seam top coal caving mining face is generally 2000m 3 / min, the return air volume is about 1600m 3 / min, therefore, as far as the undergro...

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Problems solved by technology

And the air intake of the fully mechanized coal seam top coal caving mining face is generally 2000m 3 / min, the return air volume is about 1600m 3 / min, therefore, as far as the underground coal recovery working face of this type of mine is concerned, the air leakage in the goaf caused by the gas drainage is likely to cause the spontaneous combustion of the remaining coal in the goaf, and the spontaneous combustion of the coal body becomes gas combustion and gas The ignition source of the explosion not only seriously affects the safety of gas extraction, but also becomes a huge source of danger in mine production; conversely, in the process of preventing spontaneous combustion, the goaf and coal blockage adopted to reduce air leakage and loose coal Measures such as pouring anti-fire yellow mud colloid into the body to form isolation zones are not conducive to gas drainage in goafs

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