Bu Yajie, Li Chang, Amyotte Paul, Yuan Wenbo, Yuan Chunmiao, Li Gang
Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines, Northeastern University, Shenyang 110819, China; Fire & Explosion Protection Laboratory, Northeastern University, Shenyang 110004, China.
Department of Civil Engineering, Shenyang Jianzhu University, Shenyang 110168, China.
J Hazard Mater. 2020 Jan 5;381:120968. doi: 10.1016/j.jhazmat.2019.120968. Epub 2019 Aug 5.
Adding solid inertants to combustible dust is one measure to prevent and mitigate dust explosions. AlO at four particle size distributions was used to determine the minimum ignition energy (MIE) and maximum explosion pressure (P) of aluminum dust and thus examine the effect of particle size on the inerting efficiency. It was interesting to observe that nano-sized AlO powder showed excellent promise as a solid inertant, having inerting efficacy superior to that of micro-sized AlO. In addition to thermal inhibition, nano AlO contributed to explosion moderation by binding Al particles together forming larger-sized aggregates that reduce dispersion in the dust clouds, and thus alleviate explosion hazards. Ignition sensitivity increased when micro-sized AlO was admixed at 5 or 10% with 1000-1500 g/m Al mixtures, an effect apparently caused by a 20% decrease in effective particle size distribution brought on by the AlO addition. Generally, increasing the amount of admixed AlO increased MIE and decreased P of Al dust clouds, and decreasing the particle size of AlO resulted in better inerting performance on moderating both the likelihood of the ignition and the consequence of the explosion.
向可燃粉尘中添加固体惰性物质是预防和减轻粉尘爆炸的一项措施。使用四种粒径分布的Al₂O₃来测定铝粉的最小点火能量（MIE）和最大爆炸压力（P），从而研究粒径对惰化效率的影响。有趣的是，纳米级Al₂O₃粉末作为固体惰性物质显示出极好的前景，其惰化效果优于微米级Al₂O₃。除了热抑制作用外，纳米Al₂O₃通过将铝颗粒结合在一起形成更大尺寸的聚集体，减少了粉尘云中的分散，从而减轻爆炸危险，有助于缓和爆炸。当微米级Al₂O₃与1000 - 1500 g/m³的铝混合物以5%或10%的比例混合时，点火敏感性增加，这种效应显然是由添加Al₂O₃导致有效粒径分布降低20%引起的。一般来说，增加Al₂O₃的混合量会提高铝粉尘云的MIE并降低P，减小Al₂O₃的粒径会在缓和点火可能性和爆炸后果方面产生更好的惰化性能。
