Among the factors influencing dust explosion, the particle size distribution (PSD) is both one of the most important and complex to consider. For instance, it is commonly accepted that the explosion sensitivity increases when the particle size decreases. Such an assertion may be questionable for nano-objects which easily agglomerate. However, agglomerates can be broken during the dispersion process. Correlating the explosion parameters to the actual PSD of a dust cloud at the moment of the ignition becomes then essential. The effects of the moisture content and sieving were investigated on a nanocellulose powder and the impact of a mechanical agglomeration was evaluated using a silicon coated by carbon powder. Each sample was characterized before and after dispersion using in situ laser particle size measurement and a fast mobility particle sizer, and explosion and minimum ignition energy tests were conducted respectively in a 20 L sphere and in a modified Hartmann tube. It was observed that drying and/or sieving the nanocellulose mainly led to variations in terms of ignition sensitivity but only slightly modified the explosion severity. In contrast, the mechanical agglomeration of the silicon coated by carbon led to a great decrease in terms of ignition sensitivity, with a minimum ignition energy varying from 5 mJ for the raw powder to more than 1J for the agglomerated samples. The maximum rate of pressure rise also decreased due to modifications in the reaction kinetics, inducing a transition from St2 class to St1 class when agglomerating the dust.

在影响粉尘爆炸的因素中，粒度分布（PSD）既是最重要也是最复杂的考虑因素之一。例如，通常公认的是，当颗粒尺寸减小时，爆炸敏感性增加。对于容易团聚的纳米物体，这样的断言可能是有问题的。但是，在分散过程中，附聚物可能会破裂。因此，将点火参数与爆炸参数与粉尘云的实际PSD进行关联变得至关重要。研究了水分含量和筛分对纳米纤维素粉末的影响，并使用涂有碳粉的硅评估了机械团聚的影响。使用原位激光粒度测量和快速迁移粒度分析仪对分散前后的每个样品进行表征，爆炸和最小点火能量测试分别在20 L的球体和改进的Hartmann管中进行。观察到，干燥和/或筛分纳米纤维素主要导致着火敏感性的变化，但是仅轻微改变了爆炸的严重性。相反，被碳覆盖的硅的机械附聚导致着火敏感性大大降低，最小着火能量从原料粉末的5 mJ到附聚样品的大于1J不等。由于反应动力学的改变，最大的压力上升速率也降低了，当使粉尘团聚时，导致从St2类过渡到St1类。观察到，干燥和/或筛分纳米纤维素主要导致着火敏感性的变化，但是仅轻微改变了爆炸的严重性。相反，被碳覆盖的硅的机械附聚导致着火敏感性大大降低，最小着火能量从原料粉末的5 mJ到附聚样品的大于1J不等。由于反应动力学的改变，最大的压力上升速率也降低了，当使粉尘团聚时，导致从St2类过渡到St1类。观察到，干燥和/或筛分纳米纤维素主要导致着火敏感性的变化，但是仅轻微改变了爆炸的严重性。相反，被碳覆盖的硅的机械附聚导致着火敏感性大大降低，最小着火能量从原料粉末的5 mJ到附聚样品的大于1J不等。由于反应动力学的改变，最大的压力上升速率也降低了，当使粉尘团聚时，导致从St2类过渡到St1类。碳覆盖的硅的机械附聚导致着火敏感性大大降低，最小着火能量从原料粉末的5 mJ到附聚样品的大于1J不等。由于反应动力学的改变，最大的压力上升速率也降低了，当使粉尘团聚时，导致从St2类过渡到St1类。碳覆盖的硅的机械附聚导致着火敏感性大大降低，最小着火能量从原料粉末的5 mJ到附聚样品的大于1J不等。由于反应动力学的改变，最大的压力上升速率也降低了，当使粉尘团聚时，导致从St2类过渡到St1类。