A jet‐impactor assisted‐fluidized bed (JIAFB) for continuous de‐agglomeration of nanopowder agglomerates was presented in previous work. Therein, a jet caused agglomerates to impinge up an impactor, where they would break. However, efficient impactor positioning will be dictated by particle momentum: the product of solid concentration and velocity must be highest. Herein, the variation of solid hold‐up was measured in a fluidized bed of Fe₂O₃ nanoparticles using gamma‐ray densitometry. Behaviour was compared under minimum fluidization and bubbling regimes, over a wide range of jet velocities (0–200 m s⁻¹). A new line‐decomposition approach allowed mapping local solid distribution across seven axial and five radial positions, tangibly demonstrating how increasing the gas velocity enhanced the fluidization quality by increasing axial solid diffusivity. Conversely, increasing jet velocity locally decreased solid hold‐up in the jet‐affected zone, and brought about inhomogeneities. With this information in hand, jet‐to‐impactor distance was optimized and validated experimentally.

中文翻译：

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使用伽马射线密度计在射流撞击器辅助流化床中进行固体滞留量测量

在先前的工作中介绍了一种喷射器-冲击流化床（JIAFB），用于纳米粉体团聚体的连续解聚。其中，喷射流导致团块撞击撞击器，使撞击器破裂。但是，有效的撞击器定位将取决于颗粒动量：固体浓度和速度的乘积必须最高。本文中，使用γ射线光度法在Fe ₂ O ₃纳米颗粒的流化床中测量了固含量的变化。在最小射流速度和起泡状态下，在各种射流速度（0-200 m s ^-1）。一种新的线分解方法允许在七个轴向位置和五个径向位置上绘制局部固体分布图，从而切实地证明了提高气体速度如何通过增加轴向固体扩散率来提高流化质量。相反，增加射流速度会局部降低射流影响区的固体滞留量，并导致不均匀性。利用这些信息，可以优化并验证喷射器到撞击器的距离。