In view of problems of current gas control measures on long-distance excavation face of high gas coal roadway which have high cost and impact excavation speed due to high gas volume fraction in return air flow. it was proposed to apply short-drilling rapid drainage technology on long-distance mining face. that is. the short-drilling was used to conduct rapid and centralized drainage o... https://www.bekindtopets.com/hot-mega-Swish-Supreme-Glide-Track-White-great-pick/