Dynamic Simulation of Mixing Controlled Reactions Using CFD
In this work a finite-mode probability density function approach coupled with Computational Fluid Dynamics is discussed to study mixing controlled reactions. The governing equations of turbulent reacting flows are presented and eventually a case study is analyzed: turbulent precipitation of barium sulphate in a semi-batch Taylor-Couette reactor. The role of operating conditions on final crystal size distribution is investigated and explained. Results show that precipitation is influenced by phenomena at all scales. However, it seems that under certain conditions micro-scale mixing can be neglected whereas macro- and meso-scale mixing should never be neglected.
KeywordsComputational Fluid Dynamics Probability Density Function Mixture Fraction Injection Velocity Scalar Dissipation Rate
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- 1.Baldyga J., Bourne J.R. (1999) Turbulent mixing and chemical reactions, John Wiley and Sons Ltd, LondonGoogle Scholar
- 2.Baldyga J., Bourne J.R., Dubuis B., Etchells A.W., Gholap R.V., Zimmermann B. (1995) Jet reactor scale-up for mixing-controlled reactions. Trans IChemE 73A: 497–501Google Scholar
- 9.Baldyga J., Orciuch W. (1999) Closure Method for Precipitation in Inhomogeneous Turbulence. In: Proceeding of the 14th Symposium on Industrial Crystallization, Rugby, UK, 12–16 Sept, paper 86, 1069Google Scholar
- 10.Fluent Inc. (1995) Fluent 5 User’s Guide. Fluent Inc., Lebanon, New Hampshire, USAGoogle Scholar
- 11.Valerio S., Vanni M., Barresi A.A., Baldi G. Engineering modelling of turbulent flows in chemical engineering applications. Trends Chem. Eng. 5: 1–13 (1998)Google Scholar
- 12.Fox R.O. (1996) Computational methods for turbulent reacting flows in the chemical process industry. Revue de l’Istitut Francais du Petrole 51: 215–243Google Scholar
- 13.Randolph A.D., Larson M.A. (1988) Theory of particulate Processes, 2nd edn. Academic Press, San DiegoGoogle Scholar
- 14.Rivera T., Larson A.D. (1978) A model for the precipitation of pentaerythritol tetranitrate (PETN). Ind. Eng. Process Des. Dev. 17: 183Google Scholar
- 16.Baldyga J., Podgoroska W., Pohorecky, H. (1995) Mixing precipitation model with application to double feed semibatch precipitation. Chem. Eng. Sci. 54: 2339–2354Google Scholar
- 18.Marchisio D.L., Barresi A.A., Fox R.O., Baldi G. (2000) Comparison of different modelling approaches to turbulent precipitation. In: Van de Akker H.E.A., Derksen,J.J. (Eds.) Proc. 10th European Conference on mixing, Delft. The Nederlands, July 2–5, 2000, 77–84Google Scholar
- 21.Marchisio D.L., Fox R.O., Barresi A.A., Baldi G. (2000) A CFD approach to the description of turbulent precipitation in a semi-batch Taylor-Couette reactor. In: Proceeding of the 14th Int. Congress of Chemical and Process Engineering (CHISA2000), Praha, Czech Republic, 27–31 August, 2000, paper G8. 1Google Scholar