Method for weakening coal seam hard roof based on electric pulse technology

A hard roof and electric pulse technology, applied in earth square drilling, surface mining, underground mining, etc., can solve the problems of rock formation weakening, large water consumption, resource waste, etc., and achieve simple operation, wide application range, and low cost Effect

Active Publication Date: 2019-03-29
CHINA UNIV OF MINING & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

High-pressure hydraulic fracturing is currently the most commonly used artificial roof caving method, but this method has certain limitations. First, most rocks in the goaf have cracks, so it is difficult to meet the sealing requirements of high-pressure conditions; in addition, high-press...

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  • Method for weakening coal seam hard roof based on electric pulse technology
  • Method for weakening coal seam hard roof based on electric pulse technology
  • Method for weakening coal seam hard roof based on electric pulse technology

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] Such as figure 1 , 2 As shown in and 3, a method for weakening the hard roof of a coal seam based on electric pulse technology includes steps:

[0025] a. When the coal seam E is recovered, two rows of fracturing boreholes 10 with a diameter of 10 cm are constructed in the gap between the two hydraulic supports 12 to the roof 11 using a conventional drilling method. The distance is 3m; the first row of fracturing boreholes 13 is perpendicular to the roof, the angle between the second row of fracturing boreholes 14 and the first row of fracturing boreholes 13 is 45°, and the second row of fracturing boreholes 14 Tend to goaf C.

[0026] b. After the construction of the fracturing drilling 10 is completed, install the discharge device,

[0027] Fix the discharge electrode 4 on the front end of the high-voltage cable protective tube 15, one end of the high-voltage cable is connected to the discharge electrode 4, and the other end of the high-voltage cable passes through...

Embodiment 2

[0036] Such as figure 1 , 2 A method for weakening the hard roof of a coal seam based on electric pulse technology shown in 3 includes steps:

[0037] a. When the coal seam E is recovered, two rows of fracturing boreholes 10 with a diameter of 10 cm are constructed in the gap between the two hydraulic supports 12 to the roof 11 using a conventional drilling method. The distance between the first row of fracturing boreholes 13 is perpendicular to the roof, the angle between the second row of fracturing boreholes 14 and the first row of fracturing boreholes 13 is 45°, and the second row of fracturing boreholes 14 Tend to goaf C.

[0038] b. After the construction of the fracturing drilling 10 is completed, install the discharge device,

[0039] Fix the discharge electrode 4 on the front end of the high-voltage cable protective tube 15, one end of the high-voltage cable is connected to the discharge electrode 4, and the other end of the high-voltage cable passes through the hi...

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Abstract

Disclosed is a method for weakening a coal seam hard roof based on an electric pulse technology. A discharging electrode instantaneously discharges in water in cracked drill holes to generate rapid and powerful shock waves, so that the water around the discharging electrode generates a water hammer and a water wedge effect to impact roof rock, a roof is repeatedly impacted through repeated discharging to generate accumulated damage, the coal seam roof is weakened accordingly, effective collapse of the roof is achieved, and the problem can be effectively solved that the periodic weighing step pitch is increased due to the large area of the roof reserved in a goaf. By means of the method for weakening the coal seam hard roof based on the electric pulse technology, electric energy of high-voltage electric pulses is converted into the shock waves to break the rock stratum, and the method has the advantages of simple operation, high-efficiency cleaning, low cost and wide application range.

Description

technical field [0001] The invention relates to a roof weakening method in coal mining, in particular to a method for weakening a hard roof of a coal seam based on electric pulse technology. Background technique [0002] As the working face continues to move forward, the roof area of ​​the goaf will increase, and under the action of the gravity of the overlying strata, the energy accumulated in the working area will become larger and larger. The collapse of the rock formation will inevitably increase the difficulty of working face support. In addition, if the roof of the goaf collapses without warning, it will definitely cause a strong shock wave in the roadway, damage the equipment in the roadway and even threaten the safety of the workers in the roadway. In addition, purposeful caving can also reduce the sudden subsidence of the surface and avoid unnecessary damage. High-pressure hydraulic fracturing is currently the most commonly used artificial roof caving method, but ...

Claims

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Application Information

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IPC IPC(8): E21C41/18
CPCE21C41/18
Inventor 林柏泉张祥良李彦君朱传杰刘统李永孔佳宋浩然
Owner CHINA UNIV OF MINING & TECH
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