(238a) Flow through Packed Beds…an Inconvenient Truth

Authors: 
Arredondo, J. H. - Presenter, Rice University
Worstell, J. H., Worstell and Worstell, Consultants
Flow Through Packed Bedsâ?¦An Inconvenient Truth

Jacob Arredondo, Jonathan Worstell, and Meng Zhang

Packed beds are a staple of the chemical industry, and as such, are a critical topic in undergraduate education. Students encounter packed beds in assignments for separations, kinetics, and laboratory courses; and they are usually drawn directly to the Ergun equation for answers.

The Ergun equation, while well known, generally gives poor results, especially for non-spherical packing. Furthermore, the Ergun equation provides no available mechanism for scaling up or scaling down of chemical processes.

In this presentation, we outline a simple undergraduate experiment that demonstrates to students the ineffectiveness of the Ergun equation and facilitates the development of a better solution using dimensional analysis. This assignment is designed to promote critical thinking and shows students that textbooks and academic papers are not always the definitive authority. Additionally, with no moving parts, the experimental apparatus is very robust, i.e. student resistant, in high volume teaching laboratories.

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