Long standpipe gas extraction in worked-out section

Abstract

This is a gas extraction method via a long vertical pipe at goaf zone. Two holes are made on the top and bottom board of the air gallery at the working face. Sectional metal pipes are linked together to form a long vertical pipe, with the top sealed and inserted into the hole on the top board, and the bottom inserted into the bottom board and concreted. Small holes distributes on the pipe wall and been wrapped with pack. The pipe is connected to the extraction network. With 5m of the pipe getting into the goaf zone, start extraction; with the previous pipe getting into the goaf zone at 30m, and the following one at 5m, shut the previous pipe and open the following one. So realize a continuous extraction and decrease the gas concentration at the solid angle. The gas concentration could be controlled under 0.6%.

Description

Technical field [0001] The invention relates to a long riser gas drainage method in a goaf, and is particularly suitable for gas drainage in a goaf of a coal mining face in coal mine production safety. Background technique [0002] Coal mining face adjacent to the coal (rock) layer and goaf enters the goaf, and gushes from the upper corner along the direction of air leakage in the goaf, often causing the upper corner gas concentration to exceed the limit, and even the return air flow. The concentration exceeds the limit, which seriously affects the safety of coal mining face. In the goaf, due to the influence of air leakage, the gas is distributed vertically along the goaf, and the gas concentration in the caving zone gradually increases with height. The suction port for buried pipe gas drainage in the traditional goaf is generally arranged on the goaf floor or the suction port is raised to a position 1 to 2m away from the bottom plate. The gas concentration in this area is low,...

AI Technical Summary

Problems solved by technology

The suction port of the traditional goaf buried pipe gas drainage is generally arranged on the floor of the goaf or the suction port is raised to a position 1-2m away from the floor. The concentration of buried pipe drainage is low (the concentration is mostly 2-5%), and the effect is poor. The gas concentration in the upper corner often exceeds the limit, which affects the normal production of the working face and causes personal safety.

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