Various approaches to structure gas-solid fluidized beds are reviewed, followed by detailed discussion on the use of gas pulsation to induce dynamic structuring. Granular media are dissipative systems, which develop complex spatiotemporal patterns when excited by an oscillating energy source. Here, we discuss how such perturbations initiate surface patterns and how these could propagate into a macroscopically organized flow. We call this dynamically structured fluidization. Vibrated shallow granular layers form ordered surface waves. The hydrodynamics of pulsed gas-fluidized layers are related, but more complex: Under appropriate conditions, surface waves transition into a three-dimensionally ordered bubbling flow. This occurs in much deeper granular beds than under vibration, indicating distinct physics. In this dynamically structured state, bubbles organize into a scalable sub-harmonic, triangular lattice that is highly predictable and responsive to changes in oscillation parameters, allowing for an unprecedented level of control. Structured bubbling is observed only under sufficiently dense conditions; thus, a dynamically structured fluidized bed sits between fixed and fluidized beds, offering opportunities for process intensification, due to less macromixing than traditional fluidization, but a higher level of control through micromixing. This informs new intensified designs for processes that are highly exothermic, involve particle formation, thermally sensitive or high-value materials.

综述了各种构造气固流化床的方法，然后详细讨论了如何利用气体脉动引起动态结构化。颗粒介质是耗散系统，当被振荡的能量源激发时，它们会发展出复杂的时空模式。在这里，我们讨论了这种扰动如何引发表面图案，以及它们如何传播到宏观组织的流中。我们称这种动态结构化流化。振动的浅颗粒层形成有序的表面波。脉冲气体流化层的流体动力学是相关的，但更为复杂：在适当的条件下，表面波转变为三维有序的鼓泡流。这发生在比振动更深的颗粒床中，这表明了不同的物理学。在这种动态结构化的状态下，气泡组织成可伸缩的次谐波三角晶格，该晶格高度可预测并响应振荡参数的变化，从而实现了前所未有的控制水平。只有在足够致密的条件下才能观察到结构化的气泡。因此，动态结构化的流化床位于固定床和流化床之间，由于宏观混合比传统流化要少，因此提供了强化工艺的机会，但通过微混合可以实现更高的控制水平。这为高度放热，涉及颗粒形成，热敏或高价值材料的工艺提供了新的强化设计。