Particle resolved simulations of particle-flow interactions in fluidized beds to optimize design and operation of domestic wastewater treatment systems
Abstract/Contents
- Abstract
- Recently, the Staged Anaerobic Fluidized-bed Membrane Bioreactor (SAF-MBR), which consists of an anaerobic fluidized-bed reactor (AFBR) and a particle-sparged membrane bioreactor (P-MBR), has been developed to reduce the energy intensity of domestic wastewater treatment by using anaerobic microorganisms that convert organics into methane in the absence of aeration. While this has the potential to transform domestic wastewater treatment into an energy positive process, the moving particles in the SAF-MBR induce hydrodynamic processes related to flow-particle and particle-particle interactions that are poorly understood. With a better understanding of hydrodynamics, better design and operational practices can be developed. In this dissertation, a collocated particle resolved simulation (PRS) using the immersed boundary method (IBM) is developed to accurately quantify the fluid-particle and particle-particle interactions in a fluidized-bed reactor. This dissertation first investigates the effect of particle Reynolds number which is essentially a nondimensional flow rate that controls the bed expansion. Results imply the existence of an intermediate particle Reynolds number regime at which the combined effect of flow and collisions is optimal and both mixing in the AFBR and membrane scouring in the P-MBR are expected to be maximized. While the Reynolds number is a critical parameter, the design of fluidized beds depends critically on the Archimedes number that combines the effect of particle and fluid properties. Simulation results reveal that particles with Archimedes number greater than roughly 1000 should be used to avoid flow short-circuiting due to clusters in the AFBR and reduced membrane scouring due to ineffective collisions in the P-MBR. In industrial applications, fluidized beds typically contain particles of different sizes that tend to segregate into layers in which the particle size increases moving upward. Our simulations reveal that segregated layers behave identically as they would in their corresponding monodispersed fluidized bed layers. However, the transition region between the two segregated layers cannot be described as a simple superposition of the two segregated layers.
Description
| Type of resource | text |
|---|---|
| Form | electronic resource; remote; computer; online resource |
| Extent | 1 online resource. |
| Place | California |
| Place | [Stanford, California] |
| Publisher | [Stanford University] |
| Copyright date | 2021; ©2021 |
| Publication date | 2021; 2021 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Author | Yao, Yinuo |
|---|---|
| Degree supervisor | Criddle, Craig |
| Degree supervisor | Fringer, Oliver B. (Oliver Bartlett) |
| Thesis advisor | Criddle, Craig |
| Thesis advisor | Fringer, Oliver B. (Oliver Bartlett) |
| Thesis advisor | Hickey, Robert F |
| Thesis advisor | McCarty, Perry L |
| Degree committee member | Hickey, Robert F |
| Degree committee member | McCarty, Perry L |
| Associated with | Stanford University, Civil & Environmental Engineering Department |
Subjects
| Genre | Theses |
|---|---|
| Genre | Text |
Bibliographic information
| Statement of responsibility | Yinuo Yao. |
|---|---|
| Note | Submitted to the Civil & Environmental Engineering Department. |
| Thesis | Thesis Ph.D. Stanford University 2021. |
| Location | https://purl.stanford.edu/fk415fj3620 |
Access conditions
- Copyright
- © 2021 by Yinuo Yao
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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