Retreating type coal seam hydraulic broaching, cave-building and permeability-increasing device and permeability-increasing method

Abstract

The invention discloses a retreating type coal seam hydraulic broaching, cave-building and permeability-increasing device and a permeability-increasing method. The permeability-increasing device comprises a hydraulic broaching and cave-building rod, a broaching ejector rod, a connecting rod, a corner controller, a hydraulic oil injection pipeline, a hydraulic oil outlet pipeline, a hydraulic oil cylinder and a control device; the broaching ejector rod is a two-stage telescopic cylinder body; the extension and the compression of the two-stage telescopic cylinder body are hydraulically controlled to realize the broaching, cave-building and permeability-increasing of a coal seam drill hole; and meanwhile, the corner controller can rotate the hydraulic broaching and cave-building rod by 90 degrees, 180 degrees and 270 degrees and carry out a complete broaching and cave-building process of extending firstly and then compressing after each rotation is completed. A hydraulic ejector rod principle is adopted, so that safety and reliability are achieved, large enough pressure can be guaranteed, and finally the purposes of improving the gas extraction efficiency and shortening the gas extraction working time can be achieved.

Description

technical field [0001] The invention belongs to the technical field of anti-permeability drainage of coal seam gas, in particular to a retreating type coal seam hydraulic hole expansion and cavitation anti-permeability device and an anti-permeability method. Background technique [0002] Problems such as the complex geological structure of deep coal seams, high coal seam gas content, and high coal seam gas pressure have become more and more obvious, and gas accidents have occurred frequently across the country. Therefore, the primary task to ensure the safe production of deep gas coal mines is to eliminate the hidden dangers of gas. However, due to the common problem of low gas permeability of coal in our country, the gas extraction effect of boreholes is poor and the extraction time is long, which greatly restricts coal mines. safe and efficient production. [0003] At present, underground construction must be carried out for gas drainage in deep coal seams in my country. ...

AI Technical Summary

Problems solved by technology

Therefore, the primary task to ensure the safe production of deep gas coal mines is to eliminate the hidden dangers of gas. However, due to the common problem of low gas permeability of coal in our country, the gas extraction effect of boreholes is poor and the extraction time is long, which greatly restricts coal mines. safe and efficient production

[0003] At present, underground construction must be carried out for gas drainage in deep coal seams in my country. However, due to the characteristics of low coal hardness and poor air permeability in my country's gas mines, it directly leads to poor gas drainage effects, or greatly prolongs the gas drainage cycle and affects normal recovery. Work and other issues

The currently mainly used coal seam anti-permeability methods have the following problems: the high-pressure water coal seam anti-permeability method may cause the high-pressure water to carry the gas ejection; the method of chemical solvents to increase the gas desorption inside the low-permeability coal body may change the chemical structure of the coal body in complex underground environments , affecting the heat generation rate; traditional technical methods such as drilling through layers still cannot change the low gas permeability of the coal body and the low efficiency of gas drainage

Therefore, the present invention provides a retreating type coal seam hydraulic hole expansion device and anti-permeability method, which increases the gas permeability of the coal seam by secondary rupture in the hole, improves the efficiency of gas drainage, and solves the difficulty and danger of gas drainage. high sex problem

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