Effects of aluminum particle size distributions on the explosion behaviors of hydrogen/aluminum dust hybrid mixtures

Abstract

The effects of aluminum particle size on the explosion behaviors of hydrogen/aluminum dust hybrid explosion were studied. The results show that due to the large specific surface area of small particles, the Pex and the (dP/dt)ex increased significantly with the decrease of aluminum particle size. The maximum value of the (dP/dt)ex can reach 239 MPa/s. When the particle size of aluminum dust decreased from 56.18 μm to 5.07 μm, the flame propagation displacement changed from double peaks to a single one. The actual burn time can be fitted as a function of initial hydrogen concentration. The maximum flame propagation velocities increased significantly with the decrease of aluminum particle size. When 56.18 μm and 30.82 μm aluminum dusts were burned in hydrogen/air mixtures, the expanded porous oxide layers appeared in the residues, while there was no porous oxide layer in the explosion residues of 5.07 μm aluminum dust.