Discrete particle simulation of two-dimensional fluidized bed

Tsuji, Yutaka; Kawaguchi, Toshihiro; Tanaka, Toshitsugu

doi:10.1016/0032-5910(93)85010-7

Cited by 2,083 publications

(937 citation statements)

References 4 publications

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“…Similar results are observed for the experimental setup by Verma et al [19] and the Gidaspow model is used for the simulations presented in Section 5.3.2 since the operating regime is U/U mf ∈ [1. 25,3]. Figure 17 also distinctly shows that the choice of the drag model has a higher impact on the fluidization hydrodynamics as compared to the choice of φ (wall boundary condition).…”

Section: Comparison Of Gas-solids Drag Modelsmentioning

confidence: 94%

“…The most detailed description is the Discrete Particle Model (DPM) or the Lagrangian-Eulerian framework where the solid phase consists of individual particles interacting with each other and the continuous gas phase [3][4][5]. Current computational resources, however, limit the number of solid particles that can be tracked simultaneously making the approach only feasible for dilute solid-phase flows [6].…”

Section: Introductionmentioning

confidence: 99%

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Eulerian–Eulerian simulation of dense solid–gas cylindrical fluidized beds: Impact of wall boundary condition and drag model on fluidization

et al. 2015

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Modeling the hydrodynamics of dense-solid gas flows is strongly affected by the wall boundary condition and in particular, the specularity coefficient φ which characterizes the tangential momentum transfer from the particles to the wall. The focus of this study is to investigate the impact of φ on the fluidization hydrodynamics using a fully Eulerian description of the solid and gas phases in 3D cylindrical coordinates. In order to quantify this impact, tools for characterizing the bubbling dynamics and solids circulation are developed and applied to both lab-scale (diameters 10 cm and 14.5 cm) and pilot-scale (diameter 30 cm) cylindrical beds. Comparison of simulation predictions with experimental data for different fluidization regimes and particle properties suggests that values of φ in the range [0.01,0.3] are suitable for simulating most dense solid-gas flows of practical interest. It is also shown that for this range of φ, the fluidization hydrodynamics are not significantly dependent on the choice of φ especially as the bed diameter is increased. Additionally, 3D validation of the variable φ model by Li and Benyahia [1] shows the bubble diameter predictions to be in excellent agreement with experiment and the average value of φ predicted within the range [0.01,0.3]. Quantifying the impact of φ and establishing an appropriate range is not only important for accurate simulations at both lab and pilot scales but also validation of models and sub-models for a better understanding of the fluidization phenomenon. Finally, a comparison of the Gidaspow and Syamlal-O'Brien gas-solids drag model shows that the former is more applicable to homogeneous bubbling fluidization (U/U mf <4) while the latter is only suitable for high velocities (U/U mf >4) associated with larger bubbles and slugs.

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Section: Comparison Of Gas-solids Drag Modelsmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

Eulerian–Eulerian simulation of dense solid–gas cylindrical fluidized beds: Impact of wall boundary condition and drag model on fluidization

et al. 2015

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“…As for the inert particle fluidized bed evaporator, the formula of vapor condensation heat transfer coefficient outside the tube has already become mature. The fouling resistance at the external and internal sides of the tube wall can be obtained through the experience data, and it is not difficult to obtain the conductive thermal resistance of the wall surface [15][16][17][18]. However, the boiling heat transfer coefficient formula for inert particle fluidized bed evaporator is not mature at present, and the experimental study on the boiling heat transfer coefficient of inert particle fluidized bed evaporator will be carried out this paper.…”

Section: Theoretical Analysis Of Boiling Heat Transfermentioning

confidence: 99%

Experimental Study on Hydrodynamic Performance and Heat Transfer Mechanism of Vapor-liquid-solid Three-Phase Fluidized Bed

Guo¹,

Qi²,

Zheng³

et al. 2016

IJHT

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In consideration of the characteristics of vapor-liquid-solid three-phase fluidized bed, this evaporator is applied in the liquid food-green tea extraction liquid concentration/evaporation process in this paper. The inert particles fluidized bed evaporation experiment device is designed and built combined with the characteristics of food material concentration. In this experiment, the heat transfer mechanism and hydrodynamic performance of inert particles fluidized bed evaporator during extraction of concentrated green tea are studied, and the impact of various experimental operation parameters on the evaporation and heat transfer performance as well as pressure dropping is analyzed. Moreover, the dimensionless analysis method is used to establish a correlation formula between the heat transfer coefficient and pressure drop dimensionless number of inert particle fluidized bed evaporator according to the characteristics of inert particles fluidized bed. In addition, the fouling prevention and descaling property and hydrodynamic performance of inert particle fluidized bed evaporator are studied, providing practical significance for industrial production.

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“…51,58,59) In principle, the coupling between the continuum fluid and discrete particles can be made at different time and length scales. The most popular one is that the motion of individual particles is obtained by solving Newton's second law of motion, given by Eqs.…”

Section: Mathematical Modellingmentioning

confidence: 99%

Modelling of Multiphase Flow in a Blast Furnace: Recent Developments and Future Work

et al. 2007

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An ironmaking blast furnace is a complex multiphase flow reactor involving gas, powder, liquid and solid phases. Understanding the flow behaviour of these phases is of paramount importance to the control and optimization of the process. Mathematical modelling, often coupled with physical modelling, plays an important role in this development. Yagi 1) gave a comprehensive review of the early studies in this area in 1993. Significant progress has since been made, partially driven by the needs in research but mainly as a result of the rapid development of computer and computational technologies. This paper reviews these developments, covering the formulation, validation and application of mathematical models for gas-solid, gas-liquid, gas-powder and multiphase flows. The need for further developments is also discussed.KEY WORDS: ironmaking; blast furnace; multiphase flow; two fluid model; discrete element method. Review development. Mathematical ModellingGenerally speaking, the existing approaches to modelling the multiphase flow in a BF can be classified into two categories: continuum approach at a macroscopic level and discrete approach at a microscopic level. In the continuum approach, phases are generally considered as fully interpenetrating continuum media and described by separate conservation equations with appropriate constitutive relations and interaction terms representing the coupling between phases. The general governing equations are based on the so-called two fluid model (TFM), originally developed for gas-particle flow, [29][30][31] given by:Conservation The so-called Model A and Model B result from the treatment of the fluid pressure. For example, for gas-solid flow, Model A assumes the pressure is shared between the two phases, while in Model B, the pressure is attributed to gas phase only. 31) Model A formulation has been widely used in multiphase modelling, especially in process metallurgy. Model B formulation was recently used in the so called combined continuum and discrete method for coupled flow of continuum fluid and discrete particles. 32) The continuum approach is suitable for process modelling and applied research because of its computational convenience and efficiency. Indeed, most of the BF modelling is based on this approach. However, its effective use heavily depends on constitutive or closure relations and the momentum exchange between phases. For Newtonian fluids (gas and liquid here), these relations can be readily determined. For non-Newtonian fluids such as solids and powder, general theories are not yet available. In the past, various theories have been devised for different flow regimes (three flow regimes have been identified: quasi-static regime, rapid flow regime and a transitional regime that lies inbetween). For example, models have been proposed to derive the constitutive equations for the rate-independent deformation of granular materials based on either the plasticity theory or the double shearing theory; the rapid flow of granular materials has been described by extend...

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Discrete particle simulation of two-dimensional fluidized bed

Cited by 2,083 publications

References 4 publications

Eulerian–Eulerian simulation of dense solid–gas cylindrical fluidized beds: Impact of wall boundary condition and drag model on fluidization

Eulerian–Eulerian simulation of dense solid–gas cylindrical fluidized beds: Impact of wall boundary condition and drag model on fluidization

Experimental Study on Hydrodynamic Performance and Heat Transfer Mechanism of Vapor-liquid-solid Three-Phase Fluidized Bed

Modelling of Multiphase Flow in a Blast Furnace: Recent Developments and Future Work

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