Wind pressure air drilling equipment in downhole soft outbursting coal bed and process matched therewith

Abstract

The invention relates to wind pressure air drilling equipment in a downhole soft outbursting coal bed and a process matched therewith. At present, as the consequent layer drilling characterized by high construction speed, low cost and high gas extraction efficiency becomes the primary option for coal control and gas control in coal mines, for soft outbursting coal beds, the gas extraction efficiency is directly dependant upon the pore-forming rate of the consequent layer drilling. The equipment comprises a boring machine, an air compressor, an orifice dust collection and dust removal device, a high-strength large through-hole drill rod, a drill bit with an inner core which can automatically fall off, and an antistatic explosion-protection PVC sieve tube; the boring machine which has large power and large torque supplies power to drilling construction; the orifice dust collection and dust removal device collects and eliminates slack carried out by wind from the orifice during drilling; and the antistatic explosion-protection PVC sieve tube is transferred from the interior of the high-strength large through-hole drill rod to the bottom of the orifice without lifting a drill on the completion of drilling, and at last remains in the orifice, thereby ensuring the completeness of drilling. The equipment and the process matched therewith provided by the invention has the advantages of increasing the pore-forming rate of the consequent layer drilling in soft outbursting coal beds, improving the effect of gas extraction, improving the working atmosphere of downhole air drilling, and protecting the production safety of outbursting coal mines.

Description

technical field [0001] The invention relates to coal mine underground drilling equipment and matching technology, in particular to wind pressure air drilling equipment and matching technology in underground soft and protruding coal seams. technical background [0002] Prevention and control of coal and gas outburst is a major task faced by coal mines in my country, and gas drainage is the fundamental measure to ensure mine safety. Since the state promulgated the coal mine gas control policy, the gas drainage technology has been developing day by day. In particular, the application of grid-type dense bed-through holes has played a positive role in alleviating the pressure of gas control in soft and outburst coal seams, improving the efficiency of gas extraction, and reducing the risk of coal and gas outburst. But at the same time, the construction volume of the piercing hole is large, the cost is high, and the speed is low. Compared with the through-bed hole, the gas draina...

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Problems solved by technology

For the soft and outburst coal seam, the coal seam has poor stability, high gas content and high pressure, and hole collapse and sticking accidents are prone to occur in the process of bedding drilling, which limits the application of bedding drilling

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