Effect of a hinged rotating vent cover on a vented explosion

The opening model of a hinged rotating cover was presented and validated by experiments conducted in a custom-designed test system. Good agreement was found in both internal overpressure and opening behaviour. The effect of a rotating cover on vented explosion was studied experimentally and compared with that of a bursting cover. Experimental results show that, as the concentration increases to the stoichiometric value, the reaction becomes more intense and the rate of combustion increases. Meanwhile, the rotating cover opens faster and causes the release rate to increase, so the peak overpressure decreased. Compared with a bursting vent cover, the rotating cover has a slower opening process. So the venting and turbulence caused by the rotating cover are weaker than those when using a bursting cover, which causes a higher overpressure and a lower rate of pressure build-up. Through the use of high-speed photography, four typical stages of formation of a vented flame: cellular flame, jet flame, quenching flame, and internal combustion were observed under both rotating venting and bursting venting. The smooth opening of a rotating cover can reduce the turbulence caused by the venting itself, thus reducing the duration of the vented flame propagating outside and the occurrence of secondary explosions in the chamber.