Influence of Dust Layers in Connecting Pipes on Explosion Propagation Characteristics of Flake Aluminum Powder in Cylindrical Interconnected Vessels

Abstract

Aluminum dust explosion has become an important type of dust explosion accident. In the present work, an interconnected system is established to study the influence of accumulated dust layers in connecting pipes on explosion propagation characteristics. A high-precision computational fluid dynamics (CFD) method is applied to study the overpressure and flame development of aluminum powder explosion under the central ignition condition of two cylindrical vessels with a volume ratio of 1:5. The results show that pressure build-up in the secondary container is mainly due to the oscillating pressure wave. Moreover, compared with the ignition container, the thickness of the dust layer has a more obvious enhancement effect on the peak overpressure for the secondary container. When the ignition occurs in a large container, the dust layer is lifted in the connecting pipe under the action of the precursor pressure wave. After the jet flame enters the connecting pipe, the lifted aluminum dust participates in the explosion reaction, which significantly increases the explosion intensity. With the participation of the accumulated dust layer, the maximum overpressure of the explosion of flake aluminum dust in the interconnected system is higher than 30 bar, and the jet flame velocity is increased by 3 times. The present work can provide reference for the safety design of process equipment involving dust.

Pressure and Flame Propagation Characteristics of Suspended Coal Dust Explosions Induced by Gas Explosions

“…Wang et al 19 conducted a test of coal dust explosion induced by gas explosion in large roadway, and Yu et al 20 conducted an experimental study of coal dust explosion induced by gas explosion, and analyzed that the explosion pressure increased first and then decreased with the increase of coal dust mass, and decreased with the increase of coal dust particle size. Wang et al 21 found that deposition of aluminum powder can significantly increase flame propagation speed and explosion overpressure. Hou et al 22 found that when sedimentary coal dust with different metamorphic degrees participated in the explosion, the peak overpressure and flame propagation speed of composite explosion were positively correlated with the volatile content of coal dust.…”