Borehole high-concentration gas extraction and drainage method and device thereof

Abstract

The invention discloses a borehole high-concentration gas extraction and drainage method and a borehole high-concentration gas extraction and drainage device, which are applied to the gas extraction and drainage for all boreholes in an underground coal mine. The method comprises the steps of: providing a front hole sealing capsule and a rear hole sealing capsule or a front polyurethane reaction bag and a back polyurethane reaction bag in the extraction and drainage borehole, after fully expanding, injecting hole sealing mucus in a mucus tank between two hole sealing capsules or two polyurethane reaction bags through an injection tube by means of compressed air in the underground coal mine, wherein the gas in the borehole enters an atmospheric pressure storage tank from an extraction tube or a drainage tube, and then is stored in a high pressure storage tank through a compression pump. The device comprises a sealing device and a storing device. The sealing device comprises the two hole sealing capsules or the two polyurethane reaction bags, an injection tube and a mucus tank, the storing device comprises an extraction tube or a drainage tube, an atmospheric pressure storage tank, a compression pump and a high pressure storage tank. According to the method and the device, the problems that the holes and cracks around the extraction and drainage borehole can not be closely sealed can be solved, the structure is simple, the operation is easy, the construction cost is low and the concentration of extracted and drained gas is high.

Description

technical field [0001] The invention relates to a method and device for extracting and extracting high-concentration gas from boreholes, which is applicable to extracting and extracting borehole gas at coal mining working faces in coal mines, places where coal is uncovered in Shimen, coal lanes or rock lanes, and the like. Background technique [0002] Gas disaster is one of the main natural disasters in coal mines in my country, and has become the main contradiction restricting the safety production of coal mines. Draining coal seam gas through construction boreholes is an important means of controlling gas disasters in coal mines. In coal mine gas drainage work, the sealing quality of boreholes is the key factor of the drainage effect. [0003] At present, the most commonly used method for gas drainage sealing is to use polyurethane to seal the hole, that is, put the sealer wrapped with polyurethane material into the coal seam drill hole, and rely on the chemical reaction...

AI Technical Summary

Problems solved by technology

The principle of these two hole sealing methods is to use solid matter to seal gas matter. From the coal seam gas pressure measurement technology (CN 85106104A) invented by Academician Zhou Shining, it can be known that the solid matter of the hole sealing cannot tightly seal the cracks around the drill hole

[0004] Because after a certain period of gas extraction, the coal seam will be deformed and displaced, causing the cracks in the coal seam around the borehole to expand and develop. At this time, the outside air will enter the extraction borehole from the crack channel, resulting in gas drainage. The concentration drops obviously, which shortens the effective drainage period of the drainage borehole and reduces the utilization rate of the borehole

In addition, when the concentration of the extracted gas is reduced to less than 16% of the gas explosion limit, it will seriously affect the safety of the gas extraction system.

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