Bubbling/slugging flow behavior in a cylindrical fluidized bed: ECT measurements and two-fluid simulations

In fixed-fluidized bed reactor, laboratory evaluation of different catalyst, raw materials and process parameters can be implemented, so it has wide applications in the refining process. In this study, we focused on small fixed-fluidized bed reactor, using Eulerian-Eulerian two-fluid model, simulated the gas-solid flow behavior in it. Gas residence time distribution was measured in order to characterize macro-mixing. At the same time, by changing the reactor structure and operating conditions, we studied their effects on gas-solid macro-mixing characterization. The results show that the effects of structural parameters are larger than operating conditions, and different parameters have different effects. Different parameters can be adjusted to change the gas-solid macro-mixing characterization in small fixed-fluidized bed reactor. Therefore, the small fixed-fluidized bed reactor can provide better results in more application areas.

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Effect of a Baffle on Bubble Distribution in a Bubbling Fluidized Bed

Processes ◽

10.3390/pr9071150 ◽

2021 ◽

Vol 9 (7) ◽

pp. 1150

Author(s):

Xuelian Xing ◽

Chao Zhang ◽

Bin Jiang ◽

Yongli Sun ◽

Luhong Zhang ◽

...

Keyword(s):

Fluidized Bed ◽

Granular Flow ◽

Flow Behavior ◽

Gas Distribution ◽

Bubble Distribution ◽

Particle Flows ◽

Bubbling Fluidized Bed ◽

Group B ◽

Multi Phase ◽

Two Fluid

In this study, the multi-phase Eulerian–Eulerian two-fluid method (TFM) coupled with the kinetic theory of granular flow (KTGF) was used to investigate the hydrodynamics of particle flows (Geldart Group B) in a lab-scale bubbling fluidized bed. The goal was to improve the bubble flow behavior inside the fluidized bed to improve the distribution of an injected liquid, by increasing the flow of bubbles entering the spray jet cavity and, thus, reduce the formation of wet agglomerates. The effects of a baffle on both the injection level and the whole fluidized bed were studied. Different baffle geometries were also investigated. Adding a fluxtube to a baffle can improve the bubble flows and a long fluxtube works best at redirecting gas bubbles. Baffles tend to smooth out variations in the gas distribution caused by the non-uniform inlet gas distribution. A gas pocket appears under all the baffles.

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Influence of collisional parameters for rough particles on simulation of a gas-fluidized bed using a two-fluid model

International Journal of Multiphase Flow ◽

10.1016/j.ijmultiphaseflow.2014.12.002 ◽

2015 ◽

Vol 71 ◽

pp. 1-13 ◽

Cited By ~ 14

Author(s):

Yunhua Zhao ◽

Bing Lu ◽

Yingjie Zhong

Keyword(s):

Fluidized Bed ◽

Fluid Model ◽

Two Fluid Model ◽

Two Fluid

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Design and Simulation of a Hybrid Entrained-Flow and Fluidized Bed Mild Gasifier: Part 2—Case Study and Analysis

Volume 4: Energy Systems Analysis, Thermodynamics and Sustainability; Combustion Science and Engineering; Nanoengineering for Energy, Parts A and B ◽

10.1115/imece2011-64485 ◽

2011 ◽

Cited By ~ 1

Author(s):

A. K. M. Monayem Mazumder ◽

Ting Wang ◽

Jobaidur R. Khan

Keyword(s):

Multiphase Flow ◽

Fluidized Bed ◽

Flow Behavior ◽

Flame Temperature ◽

Heterogeneous Reactions ◽

Thermal Flow ◽

Entrained Flow ◽

Progressive Development ◽

Gasification Process ◽

Flow And Heat Transfer

To help design a mild-gasifier, a reactive multiphase flow computational model has been developed in Part 1 using Eulerian-Eulerian method to investigate the thermal-flow and gasification process inside a conceptual, hybrid entrained-flow and fluidized-bed mild-gasifier. In Part 2, the results of the verifications and the progressive development from simple conditions without particles and reactions to complicated conditions with full reactive multiphase flow are presented. Development of the model starts from simulating single-phase turbulent flow and heat transfer in order to understand the thermal-flow behavior, followed by introducing seven global, homogeneous gasification reactions progressively added one equation at a time. Finally, the particles are introduced, and heterogeneous reactions are added in a granular flow field. The mass-weighted, adiabatic flame temperature is validated through theoretical calculation and the minimum fluidization velocity is found to be close to Ergun’s correlation. Furthermore, the predicted exit species composition is consistent with the equilibrium values.

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Studies on the Fluidized Bed Electrode

International Journal of Chemical Reactor Engineering ◽

10.2202/1542-6580.1610 ◽

2008 ◽

Vol 6 (1) ◽

Cited By ~ 4

Author(s):

Siva Kumar ◽

Thilakavathi Ramamurthy ◽

Bala Subramanian ◽

Ahmed Basha

Keyword(s):

Fluidized Bed ◽

Annular Flow ◽

Flow Model ◽

Model Simulation ◽

Flow Behavior ◽

Hydrodynamic Characteristics ◽

The Core ◽

Particle Transfer ◽

Fluidized Bed Electrode

The present investigation attempts to study the hydrodynamic characteristics of the fluidized bed electrode. A core-annular flow model with a transfer of particles between core-annular layers has been proposed to describe the flow behavior of conducting particles in the fluidized bed electrode. The effect of individual parameters on the rate of the particle transfer across the layer and thickness of the core-annular has been critically examined and the model simulation has been verified with the data reported in the literature.

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