近距离下层煤开采瓦斯并层涌出的防治技术

Control Technology for Combined Gas Emission in Extraction of Contiguous Lower Seams

极近距离煤层的开采必然会给后采煤层带来瓦斯问题。当层间距很小,下层煤开采时,由于两层煤采空区在下层煤直接顶垮落后合为一体,原上层煤密闭的较高浓度的采空区内瓦斯会在负压作用下大量向工作面涌出造成瓦斯超限。研究了近距离煤层下层煤开采存在的瓦斯问题,得出在综采工作面开采过程中造成瓦斯超限的主要原因。针对这种情况,运用风窗—风机联合调压的均压通风原理,确定了相应的调压参数,现场实践结果表明,均压通风技术很好地解决了本工作面瓦斯超限的问题,达到了保障安全生产的目的。

The extraction of the coal seams with very small intervals will bring gas problems to the mining of other seams.When the lower coal seam with very small interval was extracted,the gobs of two seams will become one after the immediate roof of the lower seam was caved,and large amount of closed higher-concentration gas in the gob of the upper seam will gush out into the working face under the action of the negative pressure,which may cause the gas overrun.In this paper,study was made on the gas problems existing in the extraction of the lower seam with very small interval,and the main reasons leading to the gas overrun in fully mechanized mining were found out.To counter this situation,the constant pressurized ventilation of combined air-pressure regulation by windscreen-fan was applied and corresponding pressure regulation parameters were determined.The practical results showed that the use of the constant pressurized ventilation technology successfully solved the gas problem in this working face and achieved the purpose of guaranteeing safe production in coal mine.