Millisecond multilevel directional blasting dry ice fracturing method and exploding pipe

Abstract

The invention discloses a millisecond multilevel directional blasting dry ice fracturing method and an exploding pipe. The method comprises the following steps: 1) drilling a blast hole and a pumping hole in a coal seam working surface; 2) preparing the exploding pipe; 3) filling the exploding pipe into the blast hole, connecting the end part on the inner side of the exploding pipe with the hole bottom of the blast hole, sealing an opening part at the external end of the blast hole by using the sealing tamping plug and guiding a leg wire of a millisecond delay electric detonator of each exploding unit out of the blast hole; 4) gradually exploding each exploding unit at interval of 40 milliseconds by the millisecond delay electric detonator in the sequence from interior to exterior of the blast hole. According to the invention, the generated quantity of cracks can be effectively controlled, the extending distance of the cracks can be increased without serious damage to the hole wall, CO2 generated by dry ice subliming along with the extension of the cracks can effectively displace the coal-mine gas, the gas discharging efficiency can be increased, and meanwhile, in the subliming process of the dry ice, a large quantity of exploding heat can be absorbed, the exploding temperature can be reduced and the exploding process is more safe and reliable.

Description

technical field

[0001] The invention relates to a millisecond multi-stage directional blasting dry ice fracturing method and a blasting pipe, which are used for pre-draining coal seam gas and preventing coal and gas outburst. Background technique

[0002] The main power source of my country's national economic construction is coal, which accounts for more than 70% of my country's total energy structure. At present, there are 26,000 coal mines recorded in my country, all of which are gas mines, and more than half of them are high-gas mines. Coal mining is subject to certain conditions, including natural geological conditions, underground mining conditions, miners' skills and equipment, etc. Therefore, coal mining has problems such as poor safety and reliability, and a high incidence of safety accidents, the most serious of which is gas accidents. The frequent occurrence of gas accidents has hindered the development of the coal industry, brought great economic and psychologic...

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