Residence time distributions of different size particles in the spray zone of a Wurster fluid bed studied using DEM-CFD

Li, Liang; Remmelgas, Johan; Wachem, Berend G. M. van; Corswant, Christian von; Johansson, Mats; Folestad, Staffan; Rasmuson, Anders

doi:10.1016/j.powtec.2015.04.031

Cited by 43 publications

(24 citation statements)

References 46 publications

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“…As discussed by Li L. et al (2015b), turbulence can be neglected in this study. Hence, the continuity and momentum equations are written as follows…”

Section: Equations Of Gas Flowmentioning

confidence: 99%

“…Since the particle velocity profile is an indication of the flow distribution, DEM-CFD simulations with different flow distributions at the distributor were performed to compare the particle velocity at different heights above the distributor with the corresponding experimental data. These additional simulations were used to verify that a flow distribution for which approximately 55 % of the fluidization flow enters normal to the boundary in the central base of the distributor and 45 % enters normal to the boundary in the outer annular region (Li L. et al, 2015b) gave adequate agreement with the experimental data.…”

Section: Generalmentioning

confidence: 99%

“…In order to obtain a reasonable compromise between Table 2 The material parameters used in the numerical simulations (Roberts R. et al, 1994;Bharadwaj R. et al, 2010;Darelius A. et al, 2007;Li L. et al, 2015b) Variable Unit Value…”

Section: Generalmentioning

confidence: 99%

“…In the simulations, on the other hand, different particle trajectories are followed for 25 s. As a result, the cycle and residence time distributions were calculated from different cycles for the same tracer particle in the experiments, while they are obtained from many different particles in the DEM-CFD simulations. For the pseudo-steady particle dynamics in this fluidized bed, it is thus assumed that the information obtained (such as the particle velocity or the cycle time distribution) by following one particle for a long time is equivalent to the information obtained by following all particles for a short period of time (Li L. et al, 2015b).…”

Section: Post-processingmentioning

confidence: 99%

“…The CTD and RTD of particles in similar fluidized beds have been studied using both experimental (Mann V. and Crosby E., 1975;Shelukar S. et al, 2000;San José M.J. et al, 2013;Li L. et al, 2015a) and modeling (Fries L. et al, 2011;Yang S. et al, 2014;Li L. et al, 2015b) methods. It was found that particles spend most of the cycle time in the horizontal transport region and that different residence times in this region can cause a large variability in the cycle time, and therefore a large variability in the film thickness.…”

Section: Introductionmentioning

confidence: 99%

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Effect of Drag Models on Residence Time Distributions of Particles in a Wurster Fluidized Bed: a DEM-CFD Study

Remmelgas

Wachem

et al. 2016

KONA

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Fluidized bed coating has been used to coat pellets or tablets with functional substances for a number of purposes. In this coating process, particle wetting, drying and film formation are coupled to particle motion. It is therefore of interest to study particle motion in such fluidized beds and to use the results to develop a model for predicting the quality of the final product. In this paper, we present results from DEM-CFD simulations, i.e. discrete element method and computational fluid dynamics simulations of particle motion in a laboratory-scale Wurster fluidized bed that was also employed in positron emission particle tracking (PEPT) experiments. As the drag force is the dominant interaction between the gas flow and the particle motion in this type of fluidized bed, the effect of drag models on the particle motion is investigated. More specifically, the particle velocity and residence time distributions of particles in different regions calculated from five different drag models are presented. It is found that the Gidaspow and Tang drag models predict both particle cycle and residence times well. The HKL and Beetstra drag models somewhat overestimate the particle velocity in the Wurster tube and therefore predict a reduced number of recirculations and a significantly shorter cycle time.

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“…As discussed by Li L. et al (2015b), turbulence can be neglected in this study. Hence, the continuity and momentum equations are written as follows…”

Section: Equations Of Gas Flowmentioning

confidence: 99%

Section: Generalmentioning

confidence: 99%

Section: Generalmentioning

confidence: 99%

Section: Post-processingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Effect of Drag Models on Residence Time Distributions of Particles in a Wurster Fluidized Bed: a DEM-CFD Study

Remmelgas

Wachem

et al. 2016

KONA

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Multiscale Modeling of a Pharmaceutical Fluid Bed Coating Process Using CFD/Dem and Population Balance Models to Predict Coating Uniformity

Sarkar

Shoemaker

Doshi

et al. 2019

Chemical Engineering in the Pharmaceutical Industry

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Effects of drag force correlations on the mixing and segregation of polydisperse gas‐solid fluidized bed by CFD‐DEM simulation

Zhang

Gao

et al. 2019

Can J Chem Eng

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The dense gas-solid fluidized beds with polydisperse particles are commonly encountered in the chemical industry. In this study CFD-DEM simulation of ternary particles in a bubbling fluidized bed were studied to assess four polydisperse drag correlations, using experimental data from Olaofe et al. [1] as the benchmark. The following was shown: (i) the drag force models of Sarkar et al., [2] Cello et al., [3] and Rong et al. [4] can correctly predict the minimum fluidization velocity of the mixture of ternary particles, but Gidaspow's model significantly over-predicts this; [5] (ii) no model can accurately predict the experimental segregation degree at different gas velocity, but for the cases that were studied, the models from Cello et al. [3] and Sarkar et al. [2] correlated relatively better with Olaofe et al.'s [1] experimental data than others; and (iii) detailed force analysis found that the collisional force of each type of particles is on average not equal to zero, especially for a system that is strongly segregated. In addition, the differences of drag force for different sizes of particles are the key reason for size segregation rather than pressure gradient force.

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Residence time distributions of different size particles in the spray zone of a Wurster fluid bed studied using DEM-CFD

Cited by 43 publications

References 46 publications

Effect of Drag Models on Residence Time Distributions of Particles in a Wurster Fluidized Bed: a DEM-CFD Study

Effect of Drag Models on Residence Time Distributions of Particles in a Wurster Fluidized Bed: a DEM-CFD Study

Multiscale Modeling of a Pharmaceutical Fluid Bed Coating Process Using CFD/Dem and Population Balance Models to Predict Coating Uniformity

Effects of drag force correlations on the mixing and segregation of polydisperse gas‐solid fluidized bed by CFD‐DEM simulation

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