Particle Transport Problems at Different Scales: From Dry Powder Inhalation to Flows in Circulating Fluidized Beds | AIChE

Particle Transport Problems at Different Scales: From Dry Powder Inhalation to Flows in Circulating Fluidized Beds

Flows of particulate material mediated by interstitial gas flow arise in nature and in many processes. They manifest inhomogeneities that can be traced to hydrodynamic instabilities and interparticle forces that arise through contact, van der Waals, electrostatic interactions, and capillary and viscous forces associated with liquid bridges between particles. This presentation will touch upon a few examples and highlight the essential physics behind these complexities.

In the first example dealing with dry powder inhalation, simulations shed light on the fluidization of carrier particles decorated with active pharmaceutical ingredient (api) particles, the subsequent release of the api particles, and their transport through the mouth-throat region. In the second example dealing with the contact charging of particles in fluidized systems, I will first discuss the effect of the dielectric breakdown of the gas on the extent of contact charging in vibrated beds. I will then illustrate how electrostatic charges on the particles can lead to non-uniform flow behavior.

The third example deals with the experimental observation of loop instability in circulating fluidized beds and complementary analysis exposing the role of wall friction in standpipes in suppressing this instability. 

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  • Source:
    Lehigh University
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  • Duration:
    1.25 hours
  • PDHs: