Linking power and flow in rotor-stator mixers

John, Thomas; Panesar, J.S.; Kowalski, Adam; Rodgers, Thomas L.; Fonte, Cláudio P.

doi:10.1016/j.ces.2019.06.039

Cited by 17 publications

(13 citation statements)

References 25 publications

(35 reference statements)

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“…This relationship, being linear and with a non‐zero intercept, has not been incorporated into any other predictions of the power number in stirred vessels. The same relationship has been found for both in‐line 23–25 and batch 26,27 rotor‐stator mixers operating in the fully turbulent regime. Interestingly it was found that when changing between batch and in‐line mode in a rotor‐stator mixer, not only is the relationship between the flow number and the power number the same form, but the empirical constants are also the same.…”

Section: Introductionsupporting

confidence: 75%

“…The full equation for predicting power number in rotor‐stator mixers is given by

Po = \frac{k}{Re} + k_{1} N_{Q} + {Po}_{Z},

where k , k 1 , and Po Z are empirical constants to be obtained from experimental data which depend on the mixer geometry 27 . Of course, in the laminar regime where Re is small, the first term on the right hand side of Equation () dominates and the remaining terms are negligible.…”

Section: Introductionmentioning

confidence: 99%

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The effect of radial impeller geometry on the link between power and flow numbers

et al. 2021

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Impellers in stirred vessels are often characterized by dimensionless numbers such as the power and flow numbers. These are often crucial in determining mixing performance. Previous studies for high‐shear mixers have yielded correlations between the power, flow, and mixer geometries, since in these mixers the flow can be independently varied. For stirred vessels, dimensional analysis is typically used to develop such correlations, leading to less accurate predictive models. Here, we combine an analysis based on a balance of angular momentum balance with computational fluid dynamics simulations to comprehensively study the effect of impeller geometry on the relationship between power and flow. The results allow for the prediction of the flow generated by the impeller based on the easily measurable impeller power consumption and the geometrical dimensions of the impeller. The models are accurate over a wide range of geometries. Furthermore, we are able to predict both the primary and total flows.

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Section: Introductionsupporting

confidence: 75%

“…The full equation for predicting power number in rotor‐stator mixers is given by

Po = \frac{k}{Re} + k_{1} N_{Q} + {Po}_{Z},

Section: Introductionmentioning

confidence: 99%

The effect of radial impeller geometry on the link between power and flow numbers

et al. 2021

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“…For the purpose of revealing the effects of the operating parameters and structural parameters on the emulsification performance, the flow field is numerically studied using ANSYS Fluent. The multiple reference frames (MRF) model is adapted when solving the momentum equations for the entire domain; − that is, a rotating frame is used for the region containing the rotor while a stationary frame is used for other regions of the domain, as shown in Figure . Grids are generated in ANSYS Meshing to achieve the discretization of the computational domain and are further refined based on the velocity gradient .…”

Section: Methodsmentioning

confidence: 99%

Novel Rotor-Stator Assembly Promotes the Emulsification Performance in an Inline High-Shear Mixer

Zhao

Guo

et al. 2022

Ind. Eng. Chem. Res.

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For industrial emulsification processes, it remains a challenge to obtain desirable droplet size distribution (DSD) as well as a smaller span via facile and efficient routes. In this work, a novel blind-side rotor is designed to assemble with the stator of a laboratory-scale inline high-shear mixer equipped with an annular cylinder inside the mixing chamber (bRS HSM). The effects of operating parameters, structural parameters on the average droplet size, DSD, and span are experimentally investigated and compared with those of commercially used toothed-type rotor-stator assembly. In addition, computational fluid dynamics calculations are performed to investigate the influences on the flow field of the fluid within the HSM. The results show that the structure of the bRS HSM not only generates an optimal span but also reduces the energy consumption of the mixer, which is more advantageous for production of emulsions with narrower DSD. In the bRS HSM, Sauter mean diameter (d 32) and span decrease with increasing rotor speed but decreasing flow rate of the continuous phase, while span decreases and then increases with increasing volume fraction of the dispersed phase. Meanwhile, the effect of structural parameters on span is nonmonotonic. Furthermore, the artificial neural network (ANN) model is used to perform the correlation of d 32 and span, providing an estimation method to optimize the operating and structural parameters of the inline HSM in the emulsification process.

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“…The power consumption was calculated by the torque on the rotor in this work, which is shown in eq . , CFD simulation method is widely applied to evaluate the torque on the rotor in HSMs. − John et al validated the CFD simulation method to predict the power consumption by experimental measurements in both inline and batch HSMs. where N denotes the rotor speed and M represents the torque on the rotor.…”

Section: Experimental Methodsmentioning

confidence: 99%

Liquid–Liquid Dispersion and Selectivity of Chemical Reactions in the Inline Teethed High Shear Mixers

Guo

Zhao

et al. 2021

Ind. Eng. Chem. Res.

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The effects of various structural and operating parameters on liquid–liquid dispersion and selectivity of chemical reactions in inline single-row teethed high shear mixers (HSMs) were studied by a parallel competitive reaction system. The product distribution X S was applied to evaluate the mass transfer characteristics. The results show that X S decreases evidently at first in tandem with a slight increase as the rotor speed and flow rate rise. The results also indicate that the structural parameters of the rotors play a more important role in enhancing the mass transfer efficiency at higher rotor speed. Compared with adjusting other structural parameters, increasing the teeth number of the rotor can most significantly decrease both X S and Sauter mean drop size d 32. Computational fluid dynamics was applied to predict the flow and power characteristics. Furthermore, a dimensionless correlation for X S is established to provide references for the design and optimization of inline HSMs in liquid–liquid systems.

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Linking power and flow in rotor-stator mixers

Cited by 17 publications

References 25 publications

The effect of radial impeller geometry on the link between power and flow numbers

The effect of radial impeller geometry on the link between power and flow numbers

Novel Rotor-Stator Assembly Promotes the Emulsification Performance in an Inline High-Shear Mixer

Liquid–Liquid Dispersion and Selectivity of Chemical Reactions in the Inline Teethed High Shear Mixers

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