Developing Flow of Gas-Particle Mixtures in Vertical Ducts

Dasgupta, Sanjay; Jackson, R.; Sundaresan, Sankaran

doi:10.1021/ie9606449

Cited by 8 publications

(4 citation statements)

References 12 publications

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“…In their pioneering work, Sinclair and Jackson presented the first two-fluid model using kinetic theory to describe the particle phase in dilute vertical fully developed gas−solid flows. A number of similar models were proposed shortly thereafter. − Later, predictions were reported by various authors for developing gas-particle flows. − For the most part, however, the authors presented only limited comparisons with experimental data and little information on the calculated solid stresses.…”

Section: Introductionmentioning

confidence: 99%

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Measurement of Particle Phase Stresses in Fast Fluidized Beds

Polashenski

Chen

1999

Ind. Eng. Chem. Res.

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Despite concentrated research efforts devoted to the study of the two-phase fluid mechanics of fast fluidized beds (FFBs), the particle phase stresses in FFBs are not well-characterized. To address this problem, measurements were made of the local time-averaged solid pressure in a FFB riser for a wide range of flow conditions and bed locations. The solid-pressure values, which were several orders of magnitude smaller than the gas pressure, were found to vary primarily with the local time-averaged solid concentration. Using constitutive relations from the kinetic theory of particulate flow, values of local time-averaged solid-phase shear viscosity were calculated from the measured solid pressure and solid fraction. The calculated viscosity values were found to be intermediate within the rather wide range of estimated values previously used in various two-fluid models for dilute vertical gas-particle flow.

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Section: Introductionmentioning

confidence: 99%

“…17-20 Later, predictions were reported by various authors for developing gas-particle flows. [21][22][23][24][25][26] For the most part, however, the authors presented only limited comparisons with experimental data and little information on the calculated solid stresses.…”

Section: Introductionmentioning

confidence: 99%

Measurement of Particle Phase Stresses in Fast Fluidized Beds

Polashenski

Chen

1999

Ind. Eng. Chem. Res.

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“…Where, r o is the external diameter of immersed tube, r in is the inner diameter of the immersed tube, a f is the heat transfer coefficient between particles and the inner surface of the tube, λ is the coefficient of heat conductivity of the tube, α b is coefficient of external surface of the tube.α f is the convective heat transfer coefficient of steam, water, or air in the immersed tubes, it can be obtained from the previous literature easily. It is found that α b is influenced by fluidizing velocity, bed temperature and particle size distribution [13][14][15][16] .…”

Section: Theoretical Analysis Of Modelmentioning

confidence: 99%

Investigation on Heat Transfer Performance of External Heat Exchanger for Circulating Fluidized Bed Boiler

Zhang

Ding

Yang

et al. 2013

AMR

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A heat transfer model of external heat exchanger (EHE) in large-scale circulating fluidized bed (CFB) boiler was suggested based on experiment data and theoretical analysis. And the model parameters were also provided. With this model, the heat transfer performance of the EHE in an actual operating 300MW CFB boiler was predicted. The comparison between the model predictive results and the actual results showed that the relative error is less than 7%. This indicated that the model established in this paper is reliable and can provide a significant reference in EHE of large-scale CFB boiler design.

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“…As argued by (Dasgupta et al, 1997;Romdhana et al, 2015), transient CFD modeling and simulations require large computational effort and they were not practical to be carried over a large number of simulations or a wide range of operating conditions. Thus, significant number of studies performed on design and development of driers usually do not involve prediction of transient heat transfer phenomena.…”

Section: Introductionmentioning

confidence: 99%

On the comparison between computational fluid dynamics (CFD) and lumped capacitance modeling for the simulation of transient heat transfer in solar dryers

2019

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In this paper transient heat transfer in a solar food drier is modeled by using both computational fluid dynamics (CFD) and lumped capacitance modeling techniques. The CFD model is used to simulate the air flow and transient heat transfer within the dryer. A lumped capacitance model, developed from energy exchanges between various components of the drying chamber, is extensively compared with the results of the CFD model. The two models predict both a 40 ℃ rise in steady-state temperature within the drying chamber. Before reaching this temperature, there is about 8 ℃ RMS deviation between the transient temperature prediction of the two models. This deviation is mainly caused by the heat transfer coefficient around the food rack shelfs. Fitting these coefficients give rise to a minimal RMS deviation between the two models of 1.8℃ and 0.9℃ on the lower and upper rack shelfs respectively. The transient heat transfer phenomenon from CFD modeling also showed that the spatial distribution of temperature after 30 minutes is uniform thus validating the very assumption of lumped capacitance modeling. This demonstrates that the lumped capacitance model can supplant the computationally demanding CFD modeling technique in predicting transient heat transfer phenomenon in solar food dryers.

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Developing Flow of Gas-Particle Mixtures in Vertical Ducts

Cited by 8 publications

References 12 publications

Measurement of Particle Phase Stresses in Fast Fluidized Beds

Measurement of Particle Phase Stresses in Fast Fluidized Beds

Investigation on Heat Transfer Performance of External Heat Exchanger for Circulating Fluidized Bed Boiler

On the comparison between computational fluid dynamics (CFD) and lumped capacitance modeling for the simulation of transient heat transfer in solar dryers

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