Study on the characteristics parameters of magnesium dust explosion suppression by various inert gases

• Published in: Journal of loss prevention in the process industries Vol. 87; p. 105242
• Main Authors: Xiong, Xinyu, Gao, Kai, Ji, Changquan, Mu, Jie, Li, Bin, Zhang, Dan, Xu, Yadong, Xie, Lifeng
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2024
• Subjects: Combustion time; Explosion suppression; Heat absorption; Nitridation reaction; Explosion suppression; Nitridation reaction; Heat absorption; Combustion time
• ISSN: 0950-4230
• DOI: 10.1016/j.jlp.2023.105242

Alongside the extensive use of magnesium, dust explosion accidents have become increasingly frequent. Conducting research on suppressing magnesium dust explosions is of great significance for the healthy development of the magnesium industry. In this paper, the effects of four inert gases (CO2, N2, Ar, and He) on the explosion characteristics parameters of magnesium dust clouds with different concentrations were investigated using a closed explosion device. It was observed that at low volume fractions of inert gases in the explosion system, there were no significant differences in their effects on the explosion characteristics parameters and the combustion time of magnesium particles. In situations where there was a high level of oxygen, N2 was more effective than Ar in suppressing explosions. However, when the concentration of magnesium dust cloud was higher and the oxygen content was lower within the hybrids, N2 reacted with magnesium dust that was unable to react with oxygen. As a result, the explosion suppression effect gradually shifted from N2 being better than Ar to Ar being better than N2. Moreover, the differences in the effects of four inert gases on particle combustion time became increasingly prominent. However, in all operating conditions, CO2 demonstrated the most effective suppression of magnesium dust explosions, while He exhibited the least effective suppression effect. Furthermore, by employing a chemical reaction kinetics calculation model, it has been discovered that the content of inert gases significantly affected the combustion time and reaction mode of particle combustion, thereby causing variations in the propagation behavior of magnesium dust cloud flames. Effect of inert gas on the combustion mechanism of magnesium particles. [Display omitted] •In any conditions, CO2 inhibits magnesium powder explosion the best and He the worst.•Higher oxygen in system, less effect of inert gas on hybrid Pmax and combustion time.•The nitriding reaction significantly affects magnesium powder explosion inhibition.•Particle combustion time kinetic calculation must consider nitriding reaction effect.•Rising Mg dust concentration made inert gas totally inhibiting its explosion harder.