Brief review on passive and active methods for explosion and detonation suppression in tubes and galleries

Abstract

Gaseous and dust (including hybrid) explosions often occur in mines, grain elevators, and industrial plants, and always lead to severe damage. Strategies for suppressing or mitigating explosions are developed based on an understanding of their physical mechanism. This study briefly summarized previous studies on explosions, detonations, and the deflagration-to-detonation transition (DDT), and then discussed potential passive/active or hybrid methods for suppressing explosions and detonation in tubes and galleries. Suppression can be achieved using methods that are focused on eliminating or mitigating factors that can either promote the reactive process or break down the DDT process. These methods involve lowering temperature and pressure, diluting the mixture concentration, and venting the closed system. The method of tuning wall materials (using aerogel) is also validated for the effectiveness of detonation suppression. By using various sensors to detect propagating flames or pressure increases in tubes or galleries, active systems can disperse a suppressing agent to extinguish combustion in a timely manner. It is commonly regarded that the active systems are superior to passive methods that operate without additional control units in some ways, but there are always limitations on the application due to reasons such as the cost of equipment, regular maintenance as well as reliability of the complicated integrated-systems. Practice applications show that there is no method of explosion prevention is absolutely safe. In reality, people must consider various factors in the development of an explosion/detonation suppression system to reduce the risk to an acceptable level.