CFD simulation of liquid-phase mixing in solid–liquid stirred reactor

Abstract Solid suspension characteristics were predicted by computational fluid dynamics (CFD) simulation in a stirred tank driven by a dual rigid-flexible impeller and a dual punched rigid-flexible impeller. An Eulerian-Eulerian approach, standard k-ε turbulence model, and multiple reference frames (MRF) technique were employed to simulate the solid-liquid two-phase flow, turbulent flow, and impeller rotation in the stirred tank, respectively. The CFD results showed that dual punched rigid-flexible impeller could increase the axial velocity and turbulent kinetic energy dissipation rate, and decrease the quantity of sediment solid particles compared with dual rigid-flexible impeller. Less impeller power was consumed by dual punched rigid-flexible impeller compared with dual rigid-flexible impeller at the same impeller speed. It was found that punched rigid-flexible impeller was more efficient in terms of solid suspension quality than dual rigid-flexible impeller at the same Pw. The simulated results for the axial solid concentration were in good agreement with the experimental data.

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Novel multistage solid–liquid circulating fluidized bed: liquid phase mixing characteristics

Particulate Science And Technology ◽

10.1080/02726351.2018.1522403 ◽

2019 ◽

Vol 38 (2) ◽

pp. 144-155 ◽

Cited By ~ 1

Author(s):

Manjusha A. Thombare ◽

Dinesh V. Kalaga ◽

Sandip B. Bankar ◽

Rahul K. Kulkarni ◽

Satchidanand R. Satpute ◽

...

Keyword(s):

Liquid Phase ◽

Fluidized Bed ◽

Circulating Fluidized Bed ◽

Phase Mixing ◽

Mixing Characteristics ◽

Solid Liquid

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CFD Simulation of Mixing Effects in Gas-Liquid-Solid Stirred Reactor

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.383-390.5778 ◽

2011 ◽

Vol 383-390 ◽

pp. 5778-5784

Author(s):

Jian Xin Xu ◽

Hua Wang ◽

Jian Jun Wang ◽

Shi Bo Wang ◽

Dao Fei Zhu ◽

...

Keyword(s):

Phase Transition ◽

Cfd Simulation ◽

Mixing Time ◽

Betti Numbers ◽

Phase Mixing ◽

Computational Homology ◽

Stirred Reactor ◽

Three Phase ◽

Fluent Software ◽

Novel Method

In order to analyze the complex phase transition in the gas-liquid-solid three-phase mixing systems and to predict gas-liquid-solid multiphase mixing time, a novel method combined image processing technology, computational homology and CFD (Computational Fluid Dynamics) numerical simulation is introduced in this study. Firstly, the volume of fluid (VOF) multiphase flow model in FLUENT software is used for the simulation of fluid characteristics. Secondly the patterns produced by phase transition in the stirred tank are binaryzed. Finally evolution profile of the zeroth dimensional Betti numbers and the first dimensional Betti numbers in time series are obtained separately. In fact,some aggregates still remain in the tank after the homogeneous mixing.Comparing with the fractal method to characterize the mixing time, the result shows that this method not only can predict the gas-liquid-solid mixing time by the zeroth dimenstional Betti numbers, but also can predict the amount of these aggregates in the stired tank by the first dimenstional Betti numbers, leading to a useful parameter to characterize the non-uniformity of gas-liquid-solid mixing.

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