According to standard procedures, flammability and explosion parameters for dusts and dust mixtures are evaluated in 20 L and/or 1 m³ vessels, with equivalent results provided a correct ignition delay time (60 ms in the 20 L vessel; 600 ms in the 1 m³ vessel). In this work, CFD simulations of flow field and dust concentration distribution in the 1 m³ spherical vessel are performed, and the results compared to the data previously obtained for the 20 L. It has been found that in the 1 m³ vessel, the spatial distribution of the turbulent kinetic energy is lower and much more uniform. Concerning the dust distribution, as in the case of the 20 L, dust is mainly concentrated at the outer zones of the vortices generated inside the vessel. Furthermore, an incomplete feeding is attained, with most of the dust trapped in the perforated annular nozzle. Starting from the maps of dust concentration and turbulent kinetic energy, the deflagration index K_St is calculated in both vessels. In the conditions of the present work, the K_St is found to be 2.4 times higher in the 20 L than in the 1 m³ vessel.

根据标准程序，在20 L和/或1 m ³容器中评估粉尘和粉尘混合物的可燃性和爆炸参数，等效结果可提供正确的点火延迟时间（20 L容器中为60 ms； 1 L中为600 ms m ³容器）。在这项工作中，对1 m ³球形容器中的流场和粉尘浓度分布进行了CFD模拟，并将结果与​​先前获得的20 L数据进行了比较。发现在1 m ^3中容器中，湍动能的空间分布较低，并且更加均匀。关于粉尘分布，与20L的情况一样，粉尘主要集中在容器内部产生的涡流的外部区域。此外，进料不完全，大部分灰尘被捕获在穿孔的环形喷嘴中。从粉尘浓度和湍动能图开始，计算两个容器的爆燃指数K _St。在当前工作条件下，发现20 L中的K _St比1 m ³容器中的K _St高2.4倍。