Schatzel S J, Gangrade V, Addis J D, Hollerich C A, Chasko L L
National Institute for Occupational Safety and Health (NIOSH), 626 Cochrans Mills Rd, Pittsburgh, PA 15236, USA.
Min Metall Explor. 2019 Feb 15;36(3):531-539. doi: 10.1007/s42461-019-0049-7.
A ventilation study using tracer gas was conducted at a western US coal mine. The objective of the study was to evaluate the movement of longwall face air exchanges between the face and worked-out area and to document the presence or absence of face airflow pathways between these locations. The mine operator uses a bleederless longwall ventilation system with a back return and a blowing mine ventilation system. The study was conducted on an active panel and included both underground and surface monitoring sites. The study used sulfur hexafluoride (SF) released as a slug on the longwall face and in the front of the gob inby the face. The velocity of the tracer gas movement in the gob was 0.019 m/s (3.7 fpm). The rate of movement for the overall tracer gas slug averaged about 0.0091 m/s (1.8 fpm). A separate tracer gas test initiated with the release of SF into the legs of the first shield showed the existence of more than one pathway of face air in the general direction from the headgate towards the tailgate corner. Maintaining adequate ventilation air on longwall faces is important for worker safety and for the dilution of methane emitted from the face and caved gob. A more detailed characterization of longwall system air and gas movement allows a mine to better assess its ventilation design for controlling gas on the face and in the gob.
在美国西部的一座煤矿进行了一项使用示踪气体的通风研究。该研究的目的是评估长壁工作面与采空区之间的风流交换情况，并记录这些位置之间是否存在工作面风流通道。该煤矿运营商采用了一种无辅扇长壁通风系统，带有回风巷和压入式矿井通风系统。该研究在一个正在开采的采区进行，包括地下和地面监测点。该研究使用了在长壁工作面上和采空区前方以团状释放的六氟化硫（SF）。示踪气体在采空区内的移动速度为0.019米/秒（3.7英尺/分钟）。整个示踪气体团的移动速度平均约为0.0091米/秒（1.8英尺/分钟）。一项单独的示踪气体测试，通过向第一个掩护支架的立柱内释放SF启动，结果表明，在从运输巷朝回风巷角落的大致方向上，存在多条工作面风流通道。在长壁工作面上保持充足的通风风流对于工人安全以及稀释从工作面和垮落采空区释放的甲烷非常重要。对长壁系统风流和瓦斯运移进行更详细的表征，有助于煤矿更好地评估其通风设计，以控制工作面上和采空区内的瓦斯。
