Preventing explosions from happening requires a good understanding of the characteristics of a gas explosion. The effect of methane concentration, coal dust concentration and igniters energy on explosion characteristics were investigated using a 1 m~3 spherical vessel. The pressure rise increased from 6.8 bar for a 6.5% methane mixture to 8.1 and 8.3 bar for 9.5% and 11.0% methane mixtures respectively. Additionally; the rates of pressure rise increased from 222 to 517 bar.s~(-1) for the range of methane mixtures exploded. The severity of the explosions increased with increasing igniter energy. The maximum pressure rise rate increased from 83 bar.s~(-1) for 1 kJ igniter to 90 bar.s~(-1) for 2 kJ igniter, to 155 bar.s~(-1) for 5 kJ igniter and to 222 bar.s~(-1) for 10 kJ igniter. The severity of the explosions increased with increased coal dust concentration. At 2.5% methane-air mixture, the pressure rise rate increased from 4 bar.s~(-1) to 114 bar.s~(-1) when the coal dust concentration increased from 50 g.m~(-3) to 100 g.m~(-3), respectively.
展开▼
