Application research on fixed-point sampling of negative pressure slag discharge for coal seam gas content determination
Jiao Jihong 1, Wang Yujie 1, Li Hui 2, 3, 4
1. Gas Institute of Pingdingshan Tianan Coal Industry Co., Ltd., Pingdingshan 467099, China ; 2. Safety Science and Engineering College of Henan Polytechnic University, Jiaozuo 454003, China ; 3. Coal safety production and efficient and clean utilization of the province to build collaborative innovation center, Jiaozuo 454003, China; 4. School of Urban Construction and Safety Engineering, Shanghai University of Applied Sciences, Shanghai 201418, China
Abstract： In order to investigate the reliability and application effect of coal seam gas content determination by negative pressure slag discharge fixed-point sampling, the field application experiment of coal seam gas content determination was carried out by using the self-designed negative pressure fixed-point sampling system. The results show that the amount of coal samples taken by the negative pressure sampling system within 30s can meet the requirements of coal seam gas content determination, and rapid sampling can be realized. In the process of negative pressure sampling, with the increase of drilling depth, the pressure drop and air volume of the negative pressure sampling system gradually decrease. Negative pressure sampling can greatly improve the purity of coal samples. The gas loss, on-site desorption and laboratory desorption of coal seam measured by negative pressure sampling were significantly increased, and the gas content of coal seam increased by 45% -80.3% compared with that of air pressure sampling.
