Numerical simulation of single and multiple gas jets in bubbling fluidized beds

Li, Tingwen; Pougatch, Konstantin; Salcudean, M.; Grecov, Dana

doi:10.1016/j.ces.2009.07.024

Cited by 37 publications

(14 citation statements)

References 52 publications

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“…This is perhaps due to its compromise between computational cost, level of detail provided, and potential of applicability. As a conse quence, there is an increasing need of verification and validation of the closure models utilised in the two fluid simulation of gas fluidized beds in different operative conditions and applications (see, for instance, Peirano et al, 2001;McKeen and Pugsley, 2003;Patil et al, 2005;Taghipour et al, 2005;Li et al, 2009). However, as some authors have pointed out (Grace and Taghipour, 2004), this verification and validation should be interpreted and extra polated with caution due to the complex nature of fluidized beds.…”

Section: Introductionmentioning

confidence: 99%

Comparison between two-fluid model simulations and particle image analysis & velocimetry (PIV) results for a two-dimensional gas–solid fluidized bed

Hernández-Jiménez

Sánchez-Delgado

Gómez-García

et al. 2011

Chemical Engineering Science

109

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a b s t r a c tThis work compares simulation and experimental results of the hydrodynamics of a two dimensional, bubbling air fluidized bed. The simulation in this study has been conducted using an Eulerian Eulerian two fluid approach based on two different and well known closure models for the gas particle interaction: the drag models due to Gidaspow and Syamlal & O'Brien. The experimental results have been obtained by means of Digital Image Analysis (DIA) and Particle Image Velocimetry (PIV) techniques applied on a real bubbling fluidized bed of 0.005 m thickness to ensure its two dimensional behaviour. Several results have been obtained in this work from both simulation and experiments and mutually compared. Previous studies in literature devoted to the comparison between two fluid models and experiments are usually focused on bubble behaviour (i.e. bubble velocity and diameter) and dense phase distribution. However, the present work examines and compares not only the bubble hydrodynamics and dense phase probability within the bed, but also the time averaged vertical and horizontal component of the dense phase velocity, the air throughflow and the instantaneous interaction between bubbles and dense phase. Besides, quantitative comparison of the time averaged dense phase probability as well as the velocity profiles at various distances from the distributor has been undertaken in this study by means of the definition of a discrepancy factor, which accounts for the quadratic difference between simulation and experiments The resulting comparison shows and acceptable resemblance between simulation and experiments for dense phase probability, and good agreement for bubble diameter and velocity in two dimensional beds, which is in harmony with other previous studies. However, regarding the time averaged velocity of the dense phase, the present study clearly reveals that simulation and experiments only agree qualitatively in the two dimensional bed tested, the vertical component of the simulated dense phase velocity being nearly an order of magnitude larger than the one obtained from the PIV experiments. This discrepancy increases with the height above the distributor of the two dimensional bed, and it is even larger for the horizontal component of the time averaged dense phase velocity. In other words, the results presented in this work indicate that the fine agreement commonly encountered between simulated and real beds on bubble hydrodynamics is not a sufficient condition to ensure that the dense phase velocity obtained with two fluid models is similar to that from experimental measurements on two dimensional beds.

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Section: Introductionmentioning

confidence: 99%

Comparison between two-fluid model simulations and particle image analysis & velocimetry (PIV) results for a two-dimensional gas–solid fluidized bed

Hernández-Jiménez

Sánchez-Delgado

Gómez-García

et al. 2011

Chemical Engineering Science

109

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“…The jet penetration depth, which can be used to determine the dimensions of the effective interaction zone between the gas jet and the emulsion phase, is one of the most important parameters describing the jet phenomena (Li, Pougatch, Salcudean, & Grecov, 2009;Pei et al, 2011). Fig.…”

Section: Jet Penetration Depth and Model Validationmentioning

confidence: 99%

Three-dimensional multi-phase simulation of the mixing and segregation of binary particle mixtures in a two-jet spout fluidized bed

et al. 2015

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“…In their study, a jet velocity of 20 m/s was considered at a fluidization ratio of 1.5 times the minimum fluidization velocity. While most studies concerning jet injection into a fluidized bed deal with relatively low jet velocities (less than 20 m/s) where the turbulence in the gas phase is typically suppressed by particles, a few continuum modeling studies of high‐speed jet injection can be found in literature . Horizontal jets of velocity up to 250 m/s injected into a fluidized bed were modeled and evaluations were made only against macroscopic properties of jet penetration length and expansion angle .…”

Section: Introductionmentioning

confidence: 99%

“…While most studies concerning jet injection into a fluidized bed deal with relatively low jet velocities (less than 20 m/s) where the turbulence in the gas phase is typically suppressed by particles, a few continuum modeling studies of high‐speed jet injection can be found in literature . Horizontal jets of velocity up to 250 m/s injected into a fluidized bed were modeled and evaluations were made only against macroscopic properties of jet penetration length and expansion angle . A more detailed continuum model validation of high‐speed jet injection into a fluidized bed was conducted by Ettehadieh et al A vertical jet of velocity 90 m/s injected into a fluidized bed operated at minimum fluidization velocity was compared against mean gas and particle velocity, and solids fraction, obtained using pressure measurements and high‐speed movies.…”

Section: Introductionmentioning

confidence: 99%

Continuum model validation of gas jet plume injection into a gas–solid bubbling fluidized bed

et al. 2013

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A continuum gas–solid model that includes descriptions for solid frictional stress and a turbulent gas phase is evaluated against published experimental measurements of mean and fluctuating velocity inside the jet plume region of a bubbling fluidized bed with a high‐speed vertical jet injection. The main uncertainties in closure relations necessary in the continuum model are first identified and then determined using available experimental data. The overall model shows good agreement with both the gas and particle experimental velocity profiles. The trends in the centerline mean and fluctuating velocity with change in the fluidized state of the emulsion are also captured favorably. Main deviations between the model and experiment are noted and possible reasons for the mismatch are discussed. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3247–3264, 2013

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Numerical simulation of single and multiple gas jets in bubbling fluidized beds

Cited by 37 publications

References 52 publications

Comparison between two-fluid model simulations and particle image analysis & velocimetry (PIV) results for a two-dimensional gas–solid fluidized bed

Comparison between two-fluid model simulations and particle image analysis & velocimetry (PIV) results for a two-dimensional gas–solid fluidized bed

Three-dimensional multi-phase simulation of the mixing and segregation of binary particle mixtures in a two-jet spout fluidized bed

Continuum model validation of gas jet plume injection into a gas–solid bubbling fluidized bed

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