Effect of rear part structure of duct and nozzle position on gas explosion prevention

To better reduce the gas explosion hazard, a method of explosion prevention was developed, through which the explosion was totally suppressed. The corresponding system was designed to quench the explosion flame and terminate the propagation by extinguishing the agent sprayed after an explosion. The lower limit quantity of agent of ABC powder (NH4H2PO4 powder) required to quench the flame was considered as the difficulty standard for explosion prevention. The main experimental duct was 3.0 m long and horizontal arrangement. The rear duct was 0.5 m long, which was placed at different angles with the horizontal main duct. And its cross-section was varied in different experiments. The results showed that the 90° duct structure was most conducive to preventing the explosion, in which 10 g ABC powder was needed, while 50 g powder was needed in 180° duct structure. The cross-section reduction of the rear duct was also conducive to explosion prevention. At the positions where the nozzles were set up, the slower the flame spread, the easier the explosion prevention could be achieved. When the nozzles were set at different positions, the amount of powder required to prevent the explosion varied greatly, ranging from 5 g to more than 80 g.