The 4th International Symposium on Mine Safety Science and Engineering (ISMSSE2018)

201 / 2018-07-01 07:10:24

Study on Bulk density and Gas Concentration Influence on Inhibitive effect of Foam Metal

gas explosion; foam metal; explosion suppression and isolation; bulk density; gas concentration

Mine occupational health and environmental safety > Explosion-proof

Gas explosion in coal mines is one of the major disasters endangering miners’ lives and safety, and the spread of flame waves followed has a potential for triggering secondary gas explosions or coal dust explosions. The currently used explosion suppression and isolation materials tend to be consumed up after the explosion, and fail to block on possible secondary explosions. On the other hand, foam metal comes to gain wide attention because of its high strength against possible secondary shocks. In this paper, a self-made large-capacity gas explosion detection device was used to study the influence of foam metal bulk density and gas concentration on explosion inhibition performance of foam metal. At the same time, the damages of foam metal with different bulk density after explosions were studied. Firstly, experiments were conducted on the explosion suppression and isolation effect of foam metal with a thickness of 5cm, an average pore diameter of 30ppi, and a bulk density range of 0.33g/cm3-0.54g/cm3. The experimental results show that the higher the bulk density of the metal, the stronger the capability it has to block the explosion flame wave. The inhibitive efficiencies of foam metal with three kinds of bulk density-- 0.33g/cm3, 0.41g/cm3 and 0.51g/cm3-- were 85.45%, 90.21% and 93.64% respectively. Secondly, according to the analysis of the thickness, shape variables and damage of the foam metal, when the bulk density was greater than 0.5g/cm3, there was no seeming appearance change occurred to the metal, so it could be reused. At last, experiments were conducted with gases of 6%, 8% and 9.5% concentrations. The results showed that the change of gas concentration had little influence on the inhibitive effect of foam metal. Although the lower the gas concentration is, the better the effect, when the foam metal is appropriately located in the pipe, it can effectively suppress gas explosions at various concentrations.