Circulation of Geldart D type particles: Part I – High solids fluxes. Measurements and computation under solids slugging conditions

Kashyap, Mayank; Gidaspow, Dimitri; Koves, William J.

doi:10.1016/j.ces.2010.10.012

Cited by 22 publications

(22 citation statements)

References 79 publications

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“…Comparisons of axial solid holdups and particle velocity profiles along the bed height direction between Case 1 and Case 2 are presented in Figure 7. The results indicate that near the inlet region of the FBR, the difference is not appreciable except that oscillation created due to the inlet effect of particles [59]. In the middle-upper part of the bed vertical section, Case 2 shows a higher solid volume fraction with obvious fluctuations, and it can be observed in Figure 5b.…”

Section: Solid Volume Fractionmentioning

confidence: 79%

“…The changes of core-annulus particle flow regime cause the axial pressure gradient to be less than the weight of PE particles in the core region, while the axial pressure drop is greater than the weight of the particles in the annular area. The particle velocity is inversely related to the solids volume fraction as shown in [59]. From the comparisons of solid holdups in Figure 6b, Case 2 will lead to lower particle velocities, as shown in Figure 8b.…”

Section: Solid Volume Fractionmentioning

confidence: 88%

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A CFD-PBM model considering ethylene polymerization for the flow behaviors and particle size distribution of polyethylene in a pilot-plant fluidized bed reactor

et al. 2015

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Section: Solid Volume Fractionmentioning

confidence: 79%

Section: Solid Volume Fractionmentioning

confidence: 88%

A CFD-PBM model considering ethylene polymerization for the flow behaviors and particle size distribution of polyethylene in a pilot-plant fluidized bed reactor

et al. 2015

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“…The solids slugging can cause significant fluctuation in solid fluidization and is not recommended for normal operation of fluidized-bed reactors; however, as indicated by Kashyap et al [30], solids slugging can provide some advantages such as avoiding solids back-mixing in the near-wall region and gas bypassing the central core region. The solids slugging structure can be measured with the technology of gamma ray densitometry [30,31]. Other techniques such as particle image velocimetry (PIV), laser doppler anemometry (LDA), and fiber optic probe can also be used for the measurement of solids structure in fluidized-bed reactors [31][32][33][34].…”

Section: Cfd Simulation Resultsmentioning

confidence: 99%

“…The solids slugging structure can be measured with the technology of gamma ray densitometry [30,31]. Other techniques such as particle image velocimetry (PIV), laser doppler anemometry (LDA), and fiber optic probe can also be used for the measurement of solids structure in fluidized-bed reactors [31][32][33][34]. In this work the measurement of solids concentration was not done due to lack of these advanced measuring instruments; however, the measurement of solids concentration will be included in our future studies to improve the quality of our research.…”

Section: Cfd Simulation Resultsmentioning

confidence: 99%

Application of Scaling-Law and CFD Modeling to Hydrodynamics of Circulating Biomass Fluidized Bed Gasifier

et al. 2016

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Two modeling approaches, the scaling-law and CFD (Computational Fluid Dynamics) approaches, are presented in this paper. To save on experimental cost of the pilot plant, the scaling-law approach as a low-computational-cost method was adopted and a small scale column operating under ambient temperature and pressure was built. A series of laboratory tests and computer simulations were carried out to evaluate the hydrodynamic characteristics of a pilot fluidized-bed biomass gasifier. In the small scale column solids were fluidized. The pressure and other hydrodynamic properties were monitored for the validation of the scaling-law application. In addition to the scaling-law modeling method, the CFD approach was presented to simulate the gas-particle system in the small column. 2D CFD models were developed to simulate the hydrodynamic regime. The simulation results were validated with the experimental data from the small column. It was proved that the CFD model was able to accurately predict the hydrodynamics of the small column. The outcomes of this research present both the scaling law with the lower computational cost and the CFD modeling as a more robust method to suit various needs for the design of fluidized-bed gasifiers.

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“…The Eulerian-Granular two-fluid model (TFM) has been employed in the simulations of the gas-solid hydrodynamics of fluidized beds with Group "B" and "D" particles [1,2]. However, the application of the TFM for Group "A" particles was barely successful unless very fine grid sizes and very small time steps were used in the computations.…”

Section: Introductionmentioning

confidence: 99%

Triple Phase Simulation of Bubbling Fluidized Beds of Geldart “A” Particles with a Bubble-Based Drag Model

Wang¹,

Chen²

2017

dtcse

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Abstract.A triple-phase numerical model was developed for the simulations of gas-solid bubbling fluidized beds with Geldart "A" particles. In the model, the gas-solids suspension was modeled as a primary gas phase presented in the emulsion, a secondary gas phase presented in the bubble, and a third phase consisting of solids. A bubble-based drag model was derived taking into account of the heterogeneous flow structures of the emulsion phase. The KTGF model was used to describe the solid phase stresses. Simulations were conducted for two different scales bubbling fluidized beds of Group "A" particles. Mesh independences were confirmed up to a radial grid size of 200 times particle diameter, and the sensitivity of the transitional results on the time-steps was investigated. The predicted bed expansion and the voidage distribution, axial and radial solids volume fraction profiles, and the solids velocity vectors have been validated against literature data.

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Circulation of Geldart D type particles: Part I – High solids fluxes. Measurements and computation under solids slugging conditions

Cited by 22 publications

References 79 publications

A CFD-PBM model considering ethylene polymerization for the flow behaviors and particle size distribution of polyethylene in a pilot-plant fluidized bed reactor

A CFD-PBM model considering ethylene polymerization for the flow behaviors and particle size distribution of polyethylene in a pilot-plant fluidized bed reactor

Application of Scaling-Law and CFD Modeling to Hydrodynamics of Circulating Biomass Fluidized Bed Gasifier

Triple Phase Simulation of Bubbling Fluidized Beds of Geldart “A” Particles with a Bubble-Based Drag Model

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