The flame propagation behavior and the effect of particle agglomeration are examined by changing the size of PMMA particles in laboratory-scale experiments. PMMA particles having a very narrow size distribution are used. We show that the minimum explosible concentration increases as the particle size decreases. On the other hand, the flame propagation velocity also increases as the particle size decreases. Therefore, the minimum explosible concentration and the flame propagation velocity show the opposite dependences on the particle size. It is considered that the minimum explosible concentration is strongly affected by the interparticle distance; meanwhile, the flame propagation velocity strongly depends on the specific surface area. It has to be emphasized that the severity of the explosion can be serious for very fine particles, although the minimum explosible concentration is fairly high.

中文翻译：

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粒径和团聚对粉尘云中最小爆炸浓度和火焰传播速度的影响

在实验室规模的实验中，通过改变 PMMA 颗粒的尺寸来检查火焰传播行为和颗粒团聚的影响。使用具有非常窄尺寸分布的 PMMA 颗粒。我们表明最小爆炸浓度随着颗粒尺寸的减小而增加。另一方面，火焰传播速度也随着颗粒尺寸的减小而增加。因此，最小爆炸浓度和火焰传播速度显示出对粒径的相反依赖性。认为最小爆炸浓度受颗粒间距的影响很大；同时，火焰传播速度很大程度上取决于比表面积。必须强调的是，对于非常细小的颗粒，爆炸的严重程度可能很严重，