In Situ Local Parameter Measurements for CFD Modeling to Optimize Aeration
| Autor: | Alain Héduit, Sylvie Gillot, Arnaud Cockx, Yannick Fayolle, Michel Roustan |
|---|---|
| Přispěvatelé: | Hydrosystèmes et Bioprocédés (UR HBAN), Centre national du machinisme agricole, du génie rural, des eaux et forêts (CEMAGREF), INSA LABORATOIRE D'INGENIERIE DES PROCEDES DE L'ENVIRONNEMENT TOULOUSE, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT) |
| Rok vydání: | 2006 |
| Předmět: |
In situ
business.industry TAILLE DE BULLES General Engineering Local parameter TRAITEMENT DES EAUX USEES 02 engineering and technology 010501 environmental sciences Computational fluid dynamics 01 natural sciences 6. Clean water 020401 chemical engineering [SDE]Environmental Sciences RETENTION GAZEUSE Environmental science VITESSE HORIZONTALE DE L'EAU 0204 chemical engineering Aeration business 0105 earth and related environmental sciences Marine engineering |
| Zdroj: | 79th Annual Water Environment Federation Technical Exhibition and Conference, Dallas, USA, 21-25 Octobre 2006 79th Annual Water Environment Federation Technical Exhibition and Conference, Dallas, USA, 21-25 Octobre 2006, 2006, pp.13 |
| ISSN: | 1938-6478 |
| Popis: | [Departement_IRSTEA]MA [TR1_IRSTEA]TED / EPURE; Measurement methods to determine in situ local parameters were developed, in order to optimize design and operating parameters impacting oxygen transfer in aeration tanks equipped with EDPM membrane diffusers and slow speed mixers. New tools to measure bubble sizes and gas hold-ups were coupled with the traditional ones used to determine liquid velocities and oxygen transfer coefficients. These methods have been developed and applied to an annular loop reactor (1493 m3). Using an immersed camera, 100 bubbles are sufficient to determine the local Sauter diameter by image analysis. Obtained results are reproducible and independent of the operator. The gas hold-up, deduced from water level measurements with the help of a magnetostrictif level meter, can be determined with a confidence interval of ± 5% using an integration time of 380 s. The obtained increase in the oxygen transfer coefficient (+ 29%) with the horizontal liquid velocity (from 0 to 0.42 m/s) is mainly due to the increase of the global gas hold-up, the bubble size varying only slightly (from 0.46 to 0.43 cm). These results will be used as input data and validation data to model hydrodynamics and mass transfer, in order to set up a simulation methodology for aeration tanks using computational fluid dynamics. |
| Databáze: | OpenAIRE |
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