Research on law and mechanism of dust explosion in bag type dust collector

The bag type dust collector will accumulate dust during long-term operation, and the high temperature during operation will cause dust explosion. In this paper, with the dust removal system involved in the "8.2" Kunshan dust explosion accident taken as the research background, the minimum ignition temperature and lower explosion limit experiments are carried out on aluminum powder with different particle sizes (10-60 mu m) by using the lowest ignition temperature test device and the 20 L near-spherical explosive device. The dust concentration distribution and temperature field in the bag type dust collector are analyzed through the CFD-FLUENT software. Through the analysis of the experimental results, it is found that when the particle size of aluminum powder is 19 mu m, the minimum ignition temperature is 585 degrees C, and the lower explosion limit of concentration is 0.04 kg/m(3). The simulation results indicate that the dust particles gather in the dust collecting bucket, and the aluminothermic reaction occurs in the dust collecting bucket. The temperature of the upper and right parts in the dust collecting bucket is above 600 degrees C, which exceeds the minimum ignition temperature. At the interface between the dust hopper and the dust collecting bucket, the concentration of aluminum powder reaches 0.126 kg/m(3), which exceeds the lower explosion limit of aluminum powder. (C) 2022 Society of Powder Technology Japan Published by Elsevier B.V. All rights reserved.