Main controlling factors of air-cavitation engineering in broken soft outburst-prone coal seams

In order to research the master engineering affecting factors and affecting mechanism of air-cavitation technology, increase its application in gas governance of the broken soft outburst-prone coal seams, this paper analyzed the mechanism of air-cavitation and believed that the master affecting factors were gas injection pressure and gas injection displacement. This paper adopted numerical simulation, field experiments and formula derivation so as to research the affecting mechanism of gas injection pressure and gas injection displacement. Results suggested that the closer to the well wall, the larger the gas pressure in the coal seam, the more easily the body structure of the coal was destroyed. The effective conduction radius of gas injection pressure was 7 meters in the broken soft coal seam in this experimental area. The cave radius of one-time expansion in coal seam was about 0.1 meter. The taken out volume of coal body was positively correlated with the gas injection pressure in certain range and well positively correlated with the gas injection displacement.