UNCORRECTED PROOF CES : 8244 ARTICLE IN PRESS Chemical Engineering Science ( ) -- Contents lists available at ScienceDirect Chemical Engineering Science journal homepage: www.elsevier.com/locate/ces 1 CFD simulation of hydrodynamics of gas–liquid–solid fluidised bed reactor R. Panneerselvam, S. Savithri ∗ , G.D. Surender 3 Process Engineering and Environmental Technology Division, National Institute for Interdisciplinary Science and Technology (CSIR) (Formerly Regional Research Laboratory), Trivandrum 695 019, India 5 ARTICLE INFO ABSTRACT Article history: Received 7 January 2008 Received in revised form 8 October 2008 Accepted 16 October 2008 Keywords: CFD Hydrodynamics Fluidization Eulerian–Eulerian Multiphase flow Chemical reactors A three dimensional transient model is developed to simulate the local hydrodynamics of a gas–liquid–solid three-phase fluidised bed reactor using the computational fluid dynamics (CFD) method. The CFD simu- lation predictions are compared with the experimental data of Kiared et al. [1999. Mean and turbulent particle velocity in the fully developed region of a three-phase fluidized bed. Chemical Engineering & Technology 22, 683–689] for solid phase hydrodynamics in terms of mean and turbulent velocities and with the results of Yu and Kim [1988. Bubble characteristics in the racial direction of three-phase fludised beds. A.I.Ch.E. Journal 34, 2069–2072; 2001. Bubble-wake model for radial velocity profiles of liquid and solid phases in three-phase fluidised beds. Industrial and Engineering Chemistry Research 40, 4463–4469] for the gas and liquid phase hydrodynamics in terms of phase velocities and holdup. The flow field predicted by CFD simulation shows a good agreement with the experimental data. From the validated CFD model, the computation of the solid mass balance and various energy flows in fluidised bed reactors are carried out. The influence of different interphase drag models for gas–liquid interaction on gas holdup are studied in this work. © 2008 Published by Elsevier Ltd. 7 1. Introduction Three-phase reactors are used extensively in chemical, petro- 9 chemical, refining, pharmaceutical, biotechnology, food and environ- mental industries. Depending on the density and volume fraction 11 of particles, three-phase reactors can be classified as slurry bubble column reactors and fluidised bed reactors. In slurry bubble column 13 reactors, the density of the particles are slightly higher than the liq- uid and particle size is in the range of 5–150 m and volume fraction 15 of particles is below 0.15 (Krishna et al., 1997). Hence, the liquid phase along with particles can be treated as a homogenous liquid 17 with mixture density. But in fluidised bed reactors, the density of particles are much higher than the density of the liquid and particle 19 size is normally large (above 150 m) and volume fraction of parti- cles varies from 0.6 (packed stage) to 0.2 (close to dilute transport 21 stage). In this study, the focus is on understanding the complex hy- drodynamics of three-phase fluidised beds containing coarser par- 23 ticles of size above 1 mm. Most of the previous studies related to three-phase fluidised bed reactors have been directed towards the 25 understanding the complex hydrodynamics, and its influence on the 27 ∗ Corresponding author. Tel.: +91 471 2515264; fax: +91 471 2491712. E-mail address: sivakumarsavi@gmail.com (S. Savithri). 0009-2509/$ - see front matter © 2008 Published by Elsevier Ltd. doi:10.1016/j.ces.2008.10.052 phase holdup and transport properties. Recent research on fluidised bed reactors focuses on the following topics: 29 (a) Flow structure quantification: The quantification of flow struc- ture in three-phase fluidised beds mainly focuses on local and glob- 31 ally averaged phase holdups and phase velocities for different op- erating conditions and parameters. In literature, Rigby et al. (1970), 33 Muroyama and Fan (1985), Lee and De Lasa (1987), Yu and Kim (1988) investigated bubble phase holdup and velocity in three-phase 35 fluidised beds for various operating conditions using experimen- tal techniques like electroresistivity probe and optical fiber probe. 37 Larachi et al. (1996), Kiared et al. (1999) investigated the solid phase hydrodynamics in three-phase fluidised bed using radio active par- 39 ticle tracking. Recently Warsito and Fan (2001, 2003) quantified the solid and gas holdup in three-phase fluidised bed using the electron 41 capacitance tomography (ECT). (b) Flow regime identification: Muroyama and Fan (1985) devel- 43 oped the flow regime diagram for air–water–particle fluidised bed for a range of gas and liquid superficial velocities. Chen et al. (1995) 45 investigated the identification of flow regimes by using pressure fluc- tuations measurements. Briens and Ellis (2005) used spectral analysis 47 of the pressure fluctuation for identifying the flow regime transition from dispersed to coalesced bubbling flow regime based on various 49 data mining methods like fractal and chaos analysis, discrete wake decomposition method etc. Fraguío et al. (2006) used solid phase 51 tracer experiments for flow regime identification in three-phase flu- idised beds. 53 Please cite this article as: Panneerselvam, R., et al., CFD simulation of hydrodynamics of gas–liquid–solid fluidised bed reactor. Chemical Engineering Science (2008), doi: 10.1016/j.ces.2008.10.052