The roles of foam ceramics in suppression of gas explosion overpressure and quenching of flame propagation

In order to substantially suppress the shock waves resulting from gas explosions in coal mines as well as to reveal the mechanism of explosion flame quenching by foam ceramics, a rectangular explosion test pipe was designed, which has a 200 mm x 200 mm cross-section and is similar in shape to the roadways in coal mines. Explosion flame propagation characteristics in empty pipe and in the presence of Al(2)O(3) and SiC foam ceramics were experimentally investigated. To obtain direct observations, the flame propagation was photographed by a high-speed camera. Furthermore, the mechanism of foam ceramics affecting gas explosion propagation was analyzed. The results demonstrate that the foam ceramics attenuate drastically the maximal explosion overpressure by up to fifty percent: the interconnected micro-network structure of the foam ceramics contribute to quenching gas explosion flame and suppressing shock wave overpressure. These important findings hint that, if properly designed and deployed, this material is expected to be developed into a new suppression and isolation technique against multiple and continuous gas explosions that are presently a grave threat to production safety of coal mines across China and the rest of the world. (C) 2011 Elsevier B.V. All rights reserved.