Technology preventing gas on upper corner of coal mining working face from exceeding limit

Abstract

The invention discloses a method preventing gas on an upper corner of a coal mining working face from exceeding limit. The method includes the step a, a row of drill holes are formed in an air return roadway roof plate at 2.5m intervals from the air return upper corner of the coal mining working face, the drill holes are perpendicular to the roof plate, 2-3 drill holes are formed in each row according to the specific size of a roadway, the length of each drill hole is 6-10m, an MQT-130 type anchor cable rig is adopted to drill the holes and expand the holes, and the diameter of each drill hole after being expanded is 50mm; the step b, the drill holes are sealed, after the construction of the drill holes is completed, PVC tubes with the diameter of 40mm are used as extracting and mining tubes in the holes, the connecting position of two PVC tubes is processed in a sealed mode, the holes are sealed timely, the holes are directly sealed with a 1m iron connector wrapped with a polyurethane cotton cloth bag, and the hole sealing length is 1m; the step c, gas extracting and mining is performed in a synchronized mode, a high-pressure rubber hose with the diameter of 42 mm is used to enable the drill holes in the roof plate to be synchronized in a gas extracting and mining pipeline of an air return gate road, and the gas extracting and mining is performed.

Description

technical field [0001] The invention relates to a method for controlling gas overrun in the upper corner of a coal mining working face. Background technique [0002] The corner corner of the coal mining face refers to the end position near the gob side of the intersection of the return air flow and the return airway in the mining face. Due to the change of the main air flow direction and the limitation of the boundary geometric conditions, a vortex area is formed at the upper corner, resulting in a smaller wind speed at the upper corner of the return air flow corner near the goaf; because the gas density is smaller than the air density, the gas goes upward Accumulation and enrichment, coupled with the regular influx of gas in the goaf into the upper corner with the periodic pressure of the roof, can easily cause the gas concentration in the upper corner of the coal mining face to exceed the limit. [0003] The accumulation of gas concentration in the upper corner until it e...

AI Technical Summary

Problems solved by technology

[0004] The shortcomings of the above-mentioned prevention of gas overrun in the upper corner are:

[0005]1. The main purpose of hanging wind barriers is to increase the ventilation at the upper corner to dispel eddy currents. Difficulty, affecting production progress

[0006] 2. The cost of installing wind (water) jet ejectors is too high, and the air supply volume of ejectors is limited, so most mines do not use them

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