Particle cluster dynamics during fluidization
Particle cluster dynamics during fluidization
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DOI：
10.1016/j.ces.2013.02.047
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发表时间：
2013-08
影响因子：
4.7
通讯作者：
J. McMillan;F. Shaffer;Balaji Gopalan;J. Chew;C. Hrenya;R. Hays;S. Karri;R. Cocco
中科院分区：
文献类型：
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作者：
J. McMillan;F. Shaffer;Balaji Gopalan;J. Chew;C. Hrenya;R. Hays;S. Karri;R. Cocco
在流化单元操作的设计和优化中使用的许多方程和关联式是基于仅相互作用的颗粒是碰撞的假设。然而，高速视频和图像分析表明，在许多情况下，粒子间的相互作用超越了牛顿物理学。颗粒被发现有很强的倾向，集群，特别是罚款。结果表明，从鼓泡流化床到提升管再到射流，在许多流化环境中，颗粒聚团现象都很普遍。对于许多经验相关性，这不是一个问题，并且在实验数据的拟合中经常捕获内聚行为。对于基本模型来说，情况并非如此，因为第一原理很少包括凝聚力。如果它们被包括在内，它通常是与非机械模型，因为这些凝聚力的性质还没有完全理解。这项工作提供了一个洞察鼓泡流化床，流化床和液体射流中的颗粒聚集的性质。每种情况似乎都是由于一组不同的凝聚力或一系列凝聚力造成的。这些力量的性质进行了讨论。
Many equations and correlations used in the design and optimization of fluidized unit operations are based on the assumptions particles that interact only with each other are collisional. However, high-speed video and image analysis suggest that in many cases particle–particle interactions go beyond Newtonian physics. Particles were found to have a strong propensity to cluster, especially fines. Result shows that particle clustering is prolific in many fluidizing environments from bubbling fluidized beds to riser to jets. For many empirical correlations, this is not an issue and cohesive behavior is often captured in the fitting of the experimental data. This is not the case for fundamental models where first principles rarely include cohesive forces. If they are included it is typically with non-mechanistic models as the nature of these cohesive forces are not completely understood. This work provides an insight to the nature of particle clustering in bubbling fluidized beds, risers and liquid jets. Each case appears to be due to a set of different cohesive forces or a sequence of cohesive forces. The nature of these forces is discussed.