Study of fluid flow in baffled vessels stirred by a Rushton standard impeller

Chára, Zdeněk; Kysela, Bohuš; Konfršt, Jiří; Fořt, Ivan

doi:10.1016/j.amc.2015.06.044

Cited by 31 publications

(15 citation statements)

References 31 publications

(42 reference statements)

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“…First investigations in this field were focused on mixing time, global flow structures and gas hold-up (e.g., [6][7][8][9][10][11]), but over the years, the focus shifted from global measurements to more local experimental analysis. This shift was accompanied by a greater interest in bubble size distributions [12,13], local gas hold-up [11,14,15] and liquid and gas velocities [16,17]. However, reliable design and scale-up remains a challenging task.…”

Section: Introductionmentioning

confidence: 99%

Influence of Spacing of Multiple Impellers on Power Input in an Industrial‐Scale Aerated Stirred Tank Reactor

Fitschen

Maly

Rosseburg

et al. 2019

Chemie Ingenieur Technik

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Despite the fact that aerated stirred tank reactors are widely used in industry and often studied, their design and scale‐up still remains challenging. Especially the specific power input is a crucial and geometry‐dependent scale‐up parameter, usually calculated with the dimensionless power number Po. Within the scope of this study, the power number is measured for different stirrer types and configurations in a laboratory and an industrial‐scale aerated stirred tank reactor. Good agreements to literature are found for the unaerated case for the two‐stage stirrer configurations at different stirrer spacing for both scales. By literature only the aerated case in the laboratory scale can be predicted. Scale‐up of an aerated industrial‐scale reactor is challenging because of a specific influence of the aeration. In case of a three‐stage Rushton configuration, an asymmetrical distribution of the stirrers should be preferred to ensure a high power number as well as good power performance under aerated conditions.

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Section: Introductionmentioning

confidence: 99%

Influence of Spacing of Multiple Impellers on Power Input in an Industrial‐Scale Aerated Stirred Tank Reactor

Fitschen

Maly

Rosseburg

et al. 2019

Chemie Ingenieur Technik

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“…The performance of the stirring process in the homogenizer and the distribution of heat from the boundary layer (homogenizer-wall) are influenced by the turbulence level and the fluid bulk flow [23]. The level of heat transfer transported between the mixed and unmixed zone flow regimes is dependent on the mean velocity of the impeller.…”

Section: Resultsmentioning

confidence: 99%

Design of Stirrer Impeller with Variable Operational Speed for a Food Waste Homogenizer

2016

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Abstract:A conceptualized impeller called KIA is designed for impact agitation of food waste in a homogenizer. A comparative analysis of the performance of KIA is made with three conventional impeller types, Rushton, Anchor, and Pitched Blade. Solid-liquid mixing of a moisture-rich food waste is simulated under various operational speeds, in order to compare the dispersions and thermal distributions at homogenous slurry conditions. Using SolidWorks, the design of the impellers employs an Application Programming Interface (API) which acts as the canvas for creating a graphical user interface (GUI )for automation of its assembly. A parametric analysis of the homogenizer, at varying operational speeds, enables the estimation of the critical speed of the mixing shaft diameter and the deflection under numerous mixing conditions and impeller configurations. The numerical simulation of the moisture-rich food waste (approximated as a Newtonian carrot-orange soup) is performed with ANSYS CFX v.15.0. The velocity and temperature field distribution of the homogenizer for various impeller rotational speeds are analyzed. It is anticipated that the developed model will help in the selection of a suitable impeller for efficient mixing of food waste in the homogenizer.

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“…The discrepancy between results treated by averaging processes and results of transient simulation is indisputable. Such discrepancies of a simulation of velocity distributions (breakup of trailing vortices) were indicated in [1]. The improvement of distribution of dissipation rate inside the vessels is also useful for future development in particular processes and on aggregates or bubbles breakup modelling [2].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of the turbulent kinetic dissipation rate in an agitated vessel

et al. 2017

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Abstract. The design of agitated tanks depends on operating conditions and processes for that are used for.An important parameter for the scale-up modelling is the dissipation rate of the turbulent kinetic energy. The dissipation rate is commonly assumed to be a function of the impeller power input. But this approach gives no information about distribution of the dissipation rate inside the agitated volume. In this paper the distributions of the dissipation rate inside the agitated vessels are estimated by evaluations of the CFD (Computational Fluid Dynamics). The results obtained from RANS (Reynolds Averaged Navier-Stokes equations) k-ε turbulent model and LES (Large Eddy Simulations) with Smagorinsky SGS (Sub Grid Scale) model are compared. The agitated vessels with standard geometry equipped with four baffles and stirred by either a standard Rushton turbine or a high shear impeller were investigated. The results are compared with mean dissipation rate estimated from the total impeller power input.

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Study of fluid flow in baffled vessels stirred by a Rushton standard impeller

Cited by 31 publications

References 31 publications

Influence of Spacing of Multiple Impellers on Power Input in an Industrial‐Scale Aerated Stirred Tank Reactor

Influence of Spacing of Multiple Impellers on Power Input in an Industrial‐Scale Aerated Stirred Tank Reactor

Design of Stirrer Impeller with Variable Operational Speed for a Food Waste Homogenizer

Evaluation of the turbulent kinetic dissipation rate in an agitated vessel

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