Ignition sensitivity and propagation characteristics of aluminum dust layers under transient high temperature

Abstract

Accidental ignition and flame propagation of dust layers are common types of initiating dust chain explosion accidents. However, the current research on the transient ignition temperature and flame propagation mechanism of aluminum dust layer is not fully sufficient. In this study, the self-made experimental device and numerical simulation method are used to study the combustion process of aluminum dust layer. After the aluminum dust layer is ignited by the transient ignition temperature, the local hot spots gradually spread until the dust combustion is completed. Due to the agglomeration effect of the smaller particle size aluminum dust, the transient ignition temperature of the aluminum dust layer decreases first and then increases with the increase of the particle size. As the power of the heating device increases, the ignition temperature of the aluminum dust layer gradually decreases. The flame propagation velocity of the tiled aluminum dust layer has a U-shaped relationship with the dust layer thickness and the dust particle size. The ignition characteristics of aluminum dust layers of different aluminum powder types vary greatly. We hope this study can give a deeper understanding of the ignition characteristics of aluminum powder and provide data support for preventing dust explosion accidents.