A CFD strategy to retrofit an anaerobic digester to improve mixing performance in wastewater treatment
| Autor: | Dapelo, Davide, Bridgeman, John |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: | |
| Druh dokumentu: | Článek |
| DOI: | 10.2166/wst.2020.086 |
| Popis: | Yes To date, mixing design practice in anaerobic digestion has focussed on biogas production, but no adequate consideration has been given to energy efficiency. A coherent, comprehensive and generalized strategy based on computational fluid dynamics (CFD) modelling is proposed to improve mixing efficiency of a full-scale, unconfined gas-mixed digester for wastewater treatment. The model consists of an Euler-Lagrange (EL) model where biogas bubbles are modelled as the Eulerian dispersed phase, and non-Newtonian sludge as the Lagrangian continuous phase. Robustness tests show that mixing predictions are independent of bubble size. The CFD strategy comprises the assessment of different mixing geometries and a range of input gas flow rates. Quantitative results show that simple retrofitting measures are able to achieve a significant improvement in the degree of mixing with reduced mixing times, and consequently recommendations for best mixing geometry and gas flow rate are given. A generalization to a generic digester is discussed in a form that is readily usable by professionals and consultants. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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