Coal mine gas extraction system and method for increasing concentration of gas extraction by reducing and pore broadening

Abstract

The invention discloses a coal mine gas extraction system and method for increasing the concentration of gas extraction by reducing and pore broadening. The coal mine gas extraction system comprises acoal mine drilling machine, a drill hole drill bit, a hole sealing mechanism, a grouting piping system, a gas extraction piping system and a reamer bit. The reamer bit comprises a power transmissionmechanism and three bit fins. The power transmission mechanism comprises a sun gear and three planetary gears, the sun gear is fixedly connected to a sun gear rotating shaft, the planetary gears are rotatably connected to a planetary gear rotating shaft, the three bit fins are separately and fixedly connected to the three planetary gears, and the bit fins are connected with cutting teeth through tooth bases. A hydraulic cylinder and an ejection rod are arranged in the sun gear rotating shaft, a spiral sliding groove is formed in the ejection rod, and a sliding block is arranged on the inner wall of the sun gear rotating shaft. The method comprises the steps that 1, hole drilling is performed; 2, pore broadening is performed; 3, hole flushing is performed; 4, grouting and hole sealing are performed; and 5, gas extraction is performed. The coal mine gas extraction system and method for increasing the concentration of gas extraction by reducing and pore broadening has novel and reasonabledesign, high strength of a reamer bit and simple reaming process, can improve hole sealing quality and the concentration of gas extraction, and is practical and effective and easy to popularize.

Description

technical field [0001] The invention belongs to the technical field of coal mine gas drainage, and in particular relates to a coal mine gas drainage system and method for increasing the concentration of gas drainage by variable diameter and reaming. Background technique [0002] In recent years, gas disasters have become one of the important factors threatening mine safety production. The fundamental measure to solve mine gas accidents is to reduce the gas content in the coal seam, thereby reducing its danger. Gas pre-extraction is the most fundamental and effective measure at present, and it has been widely used in outburst mines at home and abroad. However, the gas extraction concentration in most coal mines in my country is low, and the extraction effect is generally poor. According to statistics, about 65% of bedding boreholes have a gas drainage concentration lower than 30%. The reason for the generally low gas drainage concentration is mainly the limitation of hole se...

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Problems solved by technology

The sealing quality of this method is relatively good when it is applied to drilling through layers, descending drilling, and drilling with a certain inclination angle. It is easy to form a "crescent"-shaped air leakage channel, which leads to serious air leakage in gas extraction

Since the drilling plugging is a one-time operation, the material cannot be taken out for secondary use, and the failure of the sealing means that the drilling cannot be reused

For coal mining enterprises, not only did not achieve a good governance effect, but also a large amount of engineering waste

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