The EMMS model — its application, development and updated concepts

Li, Jinghai; Cheng, C. J.; Zhang, Zhongdong; Yuan, Jie; Nemet, Anton; Fett, F.N.

doi:10.1016/s0009-2509(99)00274-2

Cited by 130 publications

(53 citation statements)

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“…One may refer to the related references (Li et al, 1999;Song, 2003) for the details of this model. Halder and Basu (1998) examined the mass transfer between gas and solid in CFB riser.…”

Section: Hydrodynamic Modelmentioning

confidence: 99%

VOC Adsorption in Circulating Gas Fluidized Bed

et al. 2005

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International audienceThe purpose of the work is to show that CFB adsorption process is technically feasible to obtain an interesting pollution abatement, and to set the bases of a process design. Experimental results are presented, obtained with toluene being adsorbed from an air stream on polymeric adsorbent in a batch operation circulating fluidized bed. This results in a breakthrough behavior at the top of the riser, analogous to a fixed-bed experiment. The existence of breakthrough curves that are astonishingly sharp in spite of the strong mixing of the solid phase implies that efficient toluene abatement can be achieved. The breakthrough curves can be used to predict the behavior of the process in a continuous mode where the adsorbent would be partially regenerated, and which would lead to an less than total toluene abatement. The shape of the breakthrough curves clearly depends on the operating parameters, in particular the gas flow rate and the solids circulation rate. The EMMS model was adapted and implemented to describe the flow pattern of gas and solid. The model predicts the relative volume fractions of these phases, the volume fractions inside each, the superficial velocities of gas and solid in each phase, and the average cluster size. From this description, an estimation of the apparent gas/solid mass transfer coefficients may be done, and their dependence on operating conditions investigated

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“…One may refer to the related references (Li et al, 1999;Song, 2003) for the details of this model. Halder and Basu (1998) examined the mass transfer between gas and solid in CFB riser.…”

Section: Hydrodynamic Modelmentioning

confidence: 99%

VOC Adsorption in Circulating Gas Fluidized Bed

et al. 2005

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“…The gassolid interactions are correspondingly resolved into the interaction between the gas and particles within each phase and that between the dense and dilute phases. In addition, the energy consumption for suspending and transporting particles, Nst, should be minimum to achieve the system stability condition [26,32]. Three gas-solid interactions, derived from the momentum balance for particles and the pressure drop balance for gas, …”

Section: Cfd Modelmentioning

confidence: 99%

Computational characterisation of intermittent hydrodynamic behaviours in a riser with Geldart A particles

Sun

Yan

2017

Powder Technology

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“…Macro-scale modelling considers the boundary effects upon the particle-fluid suspensions and interactions. Li et al [14] found the flow to be heterogenous in gas-fluid fluidisation and the effects of the boundaries can lead to axial and radial heterogeneity. These heterogeneous structures cause issues when using standard averagedbased TFM approaches as disparity between the dilute core annulus and dense wall regions are so dramatic.…”

Section: Introductionmentioning

confidence: 99%

“…These heterogeneous structures cause issues when using standard averagedbased TFM approaches as disparity between the dilute core annulus and dense wall regions are so dramatic. The EMMS drag model has been applied by key researchers within the field of fluidisation hydrodynamics [14,12,15], calculations were made and compared for the slip velocities and drag coefficients for the different interaction phases of dense clusters, dilute broth phases and interactions between them both [13]. This was further extended to show the strong dependence of the drag coefficient on simple structural differences [16] and later a decrease in drag coefficient due to local and global structural changes.…”

Section: Introductionmentioning

confidence: 99%

Three-Dimensional Modelling on the Hydrodynamics of a Circulating Fluidised Bed

Armstrong¹,

Luo²,

Gu³

2009

Inaugural US-EU-China Thermophysics Conference-Renewable Energy 2009 (UECTC 2009 Proceedings)

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The rapid depletion of oil and the environmental impact of combustion has motivated the search for clean combustion technologies. Fluidised bed combustion (FBC) technology works by suspending a fuel over a fast air inlet whilst sustaining the required temperatures. Using biomass or a mixture of coal/biomass as the fuel, FBC provides a low-carbon combustion technology whilst operating at low temperatures. Understanding the hydrodynamic processes in fluidised beds is essential as the flow behaviours causing heat distributions and mixing determine the combustion processes. The inlet velocities and different particle sizes influence the flow behaviour significantly, particularly on the transition from bubbling to fast fluidising regimes. Computational modelling has shown great advancement in its predictive capability and reliability over recent years. Whilst 3D modelling is preferred over 2D modelling, the majority of studies use 2D models for multiphase models due to computational cost consideration. In this paper, two-fluid modelling (TFM) is used to model a 3D circulating fluidised bed (CFB) initially focussing on fluid catalytic cracker (FCC) particles. The transition from bubbling to fast fluidisation over a range of velocities is explored, whilst the effects on the bubble diameter, particle distributions and bed expansion for different particle properties including particle sizes are compared. Drag models are also compared to study the effects of particle clustering at the meso-scale.

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The EMMS model — its application, development and updated concepts

Cited by 130 publications

References 0 publications

VOC Adsorption in Circulating Gas Fluidized Bed

VOC Adsorption in Circulating Gas Fluidized Bed

Computational characterisation of intermittent hydrodynamic behaviours in a riser with Geldart A particles

Three-Dimensional Modelling on the Hydrodynamics of a Circulating Fluidised Bed

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