Flame deflagration in side-on vented detonation tubes: a large scale study

Venting is often used in process industries to reduce the possibility of dangerous rises in pressure levels and the severity of explosions. To date, the effectiveness of side-on venting on methane flame deflagration in large scale operations has not been clearly addressed. This work explicitly investigates the influences of side-on venting on varied methane flame deflagration concentrations in a 30 m long Detonation Tube (DT). Results corresponding to this study prove the existence of a significant correlation between the fire and explosion driving parameters such as pressure rise and flame propagation velocity with the vent location. It observed venting the explosion at distance between 6.5 m and 20.5 m from the ignition source resulted in reducing the explosion total pressure by about 33% to 56%. For methane concentration of 7.5% the dynamic and static pressures reduced by about 66% and 33%, respectively. The reduced pressure observed to decelerate the flame velocity by about 70%. Significant pressure rise and flame deflagration velocity reductions were observed in both upstream and downstream of the DT corresponding to the location of the vent. For high methane concentrations vacuum effect observed to drawback the flame into the vent and trigger the secondary pressure rise.