Citation

Sun C. China Saf. Sci. J. 2022; 32: 136-141.

Copyright

(Copyright © 2022, China Occupational Safety and Health Association, Publisher Gai Xue bao)

DOI

10.16265/j.cnki.issn1003-3033.2022.S2.0134

PMID

unavailable

Abstract

In order to solve the problem of low oxygen in return air corners in fully mechanized coal mining face under thin bedrock with shallow burial depth in Shendong mining area, the low oxygen treatment in Jinjie Coal Mine of Shendong Coal Group was taken as the background. According to data from field observation, the formation mechanism of low oxygen in return air corners in the fully mechanized coal mining face was analyzed. Specifically, the ventilation mode and air leakage channel of the fully mechanized coal mining face, as well as atmospheric pressure variation were discussed. It was concluded that the low oxygen in return air corners in the fully mechanized coal mining face was caused by the following reasons. On the one hand, these reasons included the influx of nitrogen and carbon dioxide in the rock formation, air leakage channels in the goaf, and a decrease in atmospheric pressure. On the other hand, the vortex state of local airflow in the working face made it difficult to enter the main airflow. In view of the above reasons, some measures to treat the low oxygen in return air corners were proposed. For example, air leakage in the goaf should be reduced, and the management of floating coal in the goaf needed to be strengthened. The air guide curtain should be set, and air volume management in the working face was supposed to be enhanced. The rear windproof curtain of the support was required, and the leakage in the upper and lower corners needed to be filled and plugged. In addition, it was necessary to adjust the U⁃type ventilation mode to the partial Y⁃type or U+L⁃type ventilation mode and analyze their applicable conditions and advantages and disadvantages. The results show that the low oxygen in return air corners in the fully mechanized coal mining face can be effectively treated by some measures to optimize the ventilation system. These measures include adjusting ventilation modes, setting ventilation facilities, ensuring construction sealing, reserving coal pillars, and plugging leakage in the upper and lower corners, so as to ensure the smooth progress of safe mining. © 2022 China Safety Science Journal

Language: zh