Experimental Study of Suspended Aluminum Dust Explosion in a Large-size Horizontal Detonation Tube

Aluminum dust combustion and detonation properties have always been the focus in dust explosion domain.The process of flame acceleration,deflagration,deflagration to detonation transition(DDT) of aluminum flake dust-air mixture,was studied in an inner diameter 199mm and 29.6m long horizontal detonation tube.40 sets of dust dispersion system were used to disperse flake aluminum into detonation tube.A 40J electric spark was used to ignite aluminum dust-air mixture.Self-sustained steady detonation was observed and pressure profiles were recorded,the characteristics of deflagration to detonation transition were studied.Experimental results indicate that the distance of deflagration to detonation transition is approximately 10.15m from ignition end(dimensionless transition distance L/D is 51).In detonation propagation process,measured maximum velocity is about 1840m/s,maximum overpressure is approximately 10.5MPa.The whole detonation propagation may be divided into 4 segments,including deflagration segment,deflagration to detonation transition segment,detonation development segment and steady detonation segment.