Small-scale testing of coal dust explosion propagation and relation to active barrier suppression systems

Abstract

Abstract Coal dust explosions are a lethal threat to anyone working in an underground coal mine. Many coal mining countries including Australia and much of Europe already utilize passive barrier explosion suppressant systems but due to differences in ventilation patterns in the United States, simple passive systems such as the bagged barrier are not as cost effective. Active systems are triggered by properties of an explosion, such as pressure, heat, or light, and release or project a suppressant into the environment to suppress an explosion. To deploy an active system, the best sensor and suppressant release location and spacing must be determined; this must account for total system latency and explosive propagation speed. A 10:1 model of a longwall entry system has been developed to study the pressure wave propagation of coal dust explosions and consequent triggering of different suppressants. The scaled model, with its removable stoppings, allows multiple potential propagation pathways for an explosion to be repeatedly tested, different from typical straight shock tunnel tests. The layout also facilitates the placement of sensors and cameras to fully observe and document the tests. The pressure wave characteristics found at crosscuts and corners will aid in the development of active barrier trigger systems and spacing of suppressant release locations.