Abstract The dust cake is critical to improve the fine particle collection efficiency in the gas-solid separation process of the granular bed filter (GBF). In this work, the dust cake formation and the corresponding filtration characteristics in a cyclone-granular bed filter (C-GBF) were investigated by experiments under a constant-velocity filtering condition. It was found that cake filtration, deep-bed filtration and the corresponding transitional phenomena could be observed in the C-GBF. A critical porosity was defined to identify the transition from cake filtration to deep-bed filtration. A following parametric study showed that a higher filtration gas velocity could increase the critical porosity and made it more difficult to form a dust cake. It was also demonstrated that the critical porosity was little affected by the dust concentration. However, the time point of the transition of different filtration modes was earlier with a higher dust concentration. The inlet gas velocity ultimately resulted in the different dust concentrations into the GBF. The similar dynamic processes of cake formation were obtained for different granular sizes. These results provided a deeper understanding of the dynamic behaviors of cake formation and filtration mode transition, which played an important role in the design and the scaling-up of the C-GBF filtration systems.

中文翻译：

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旋风颗粒床过滤器的滤饼形成及过滤特性

摘要 在颗粒床过滤器（GBF）的气固分离过程中，尘饼是提高细颗粒收集效率的关键。在这项工作中，通过恒速过滤条件下的实验研究了旋风颗粒床过滤器（C-GBF）中的尘饼形成和相应的过滤特性。发现在 C-GBF 中可以观察到滤饼过滤、深床过滤和相应的过渡现象。定义了一个临界孔隙率来确定从滤饼过滤到深床过滤的过渡。以下参数研究表明，较高的过滤气体速度会增加临界孔隙率，并使形成尘饼变得更加困难。还表明临界孔隙率几乎不受粉尘浓度的影响。然而，不同过滤模式的转变时间点较早，粉尘浓度较高。入口气体速度最终导致进入 GBF 的不同粉尘浓度。对于不同的粒度，获得了相似的饼形成动态过程。这些结果提供了对滤饼形成和过滤模式转变的动态行为的更深入理解，这在 C-GBF 过滤系统的设计和放大中发挥了重要作用。