Abstract:

In order to study the influence of alumina on the explosion of aluminum powder, the explosion experiment was carried out in a self-built vertical duct. The flame structural evolution, flame front propagation and explosion overpressure waveform were analyzed. The results show that with the increase in the inerting ratio, alumina showed an obvious inhibitory effect on the flame at the aluminum explosion, and the alumina powder with small particle size had better inhibitory effect. Moreover, alumina exerted obvious inhibitory effect on flame front propagation in later stage, the flame propagation speed decreased, and the time required for the front to reach the duct exit was longer. For 4 μm alumina, the second peak overpressure disappeared at the inerting ratio of φ =30%, while the suppression efficiency was as high as 88.9% at the inerting ratio of φ =70%. However, the alumina explosion-proof effect with a particle size of 89 μm has obvious limit values. Exceeding the limit value, the explosion-proof effect is no longer improved.

Key words: aluminum explosion, alumina, inerting ratio, flame propagation, overpressure

摘要：

为研究氧化铝对铝粉爆炸的影响，在自行搭建的实验平台进行铝粉爆炸实验研究。对火焰结构演化特性、火焰锋面传播特性和爆炸超压波形分析的结果表明：在惰化比不断增加的情况下，氧化铝表现出对铝粉爆炸火焰的明显抑制作用，且粒径较小的氧化铝粉抑制效果更好；在火焰锋面传播方面，氧化铝对后期火焰锋面传播抑制效果更明显，火焰传播速度下降，锋面到达管口需要更长的时间；粒径4 μm的氧化铝在其惰化比φ=30%的条件下，第二波爆炸超压波峰消失，在惰化比φ=70%条件下，抑爆效率高达88.9%，抑爆效果十分明显。但是粒径为89 μm的氧化铝抑爆效用有明显的极限值，超过该极限值，抑爆效用不再提高。

关键词: 铝粉爆炸, 氧化铝, 惰化比, 火焰传播, 超压