Numerical and Experimental Study on Oil-water Dispersion in New Countercurrent Centrifugal Extractor

Nakase, Masahiko; Takeshita, Kenji

doi:10.1016/j.proche.2012.10.046

Cited by 15 publications

(6 citation statements)

References 6 publications

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“…Yet, none of them rely on sufficient or adequate test data to allow extrapolation to other column geometries or operating conditions. For other type of extractors conversly, comprehensive studies of the emulsification process are arising, that open the way to progressively more phenomelogical models (see e.g [9] for RDC columns, [10,11] for centrifugal contactors, etc. ).…”

Section: Introductionmentioning

confidence: 99%

On droplets size distribution in a pulsed column. Part I: In-situ measurements and corresponding CFD–PBE simulations

Amokrane

Maaß²,

Lamadie

et al. 2016

Chemical Engineering Journal

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International audienceThe pulsed column is one of the most used contactors in solvent extraction processes, especially in the nuclear fuel treatment industry and for hydrometallurgical applications. The optimisation of solvent extraction operations needs a thorough understanding of the diphasic flow’s properties inside the apparatus, especially that of the dispersed phase. For the first time, in-situ measurements of the drop size distribution (DSD) were achieved in a small diameter pulsed column (lab scale), by using the SOPAT-VF light reflectance video probe on two water-in-oil (W/O) systems exhibiting low and high viscosities of the oil phase. Separate effects of the pulse amplitude and frequency on the DSD and the phase hold-up were evidenced for both O/W systems, despite their different viscosity levels. This technique allowed very precise measurements of droplet-diameters in quite a confined space, three orders of magnitude, which is remarkable. Experimental findings allowed the validation of a computational fluid dynamics (CFD)–population balance equation (PBE) coupled model and the improvement of breakage and coalescence kernel parameters. Rupture and coalescence mechanisms were correctly captured. The dependence of emulsion’s properties on the column hydrodynamics could then be illustrated over one period of the pulsed flow. Incidence of higher levels of pulsation intensity, hardly achievable experimentally, and separate investigation of the effects of viscosity and surface tension are presented

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Section: Introductionmentioning

confidence: 99%

On droplets size distribution in a pulsed column. Part I: In-situ measurements and corresponding CFD–PBE simulations

Amokrane

Maaß²,

Lamadie

et al. 2016

Chemical Engineering Journal

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“…The extractor used in this study is the same as in our previous studies [17][18][19]. In this study, we compared the extraction performance of Cs from nitric acid in batch and continuous extraction case in various conditions.…”

Section: Experimental Setup and Conditionsmentioning

confidence: 99%

“…In light of this background, we have developed a liquid-liquid countercurrent centrifugal extractor that induces a series of Taylor vortices and we have successfully demonstrated the concept of extraction with multiple theoretical stages by the centrifugal extractor with di(ethylhexyl) phosphoric acid, which has fast extraction kinetics [17][18][19][20][21]. In this study, we focused on Cs separation from nitric acid with BOBCalixC6, which has slow extraction kinetics.…”

Section: Introductionmentioning

confidence: 99%

Multi-staging for extraction of cesium from nitric acid by a single liquid–liquid countercurrent centrifugal extractor with Taylor vortices

Nakase

Kinuhata

Takeshita

2013

Journal of Nuclear Science and Technology

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Fission products that emit considerable decay heat and radioactivity, such as 137 Cs, have a large impact on waste management. Small and high-performance extractor is desirable for separating such nuclei. In this study, we implemented the continuous extraction of Cs from nitric acid in a single liquid-liquid countercurrent centrifugal extractor with Taylor Vortices by calix [4]arene-bis(t-octylbenzo-crown-6)(BOBCalixC6) as an extractant with trioctylamine(TOA) as a suppressant and with 1-(2,2,3,3-tetrafluoropropoxy)-3-(4-secbutylphenoxy)-2-propanol (Cs-7SB) as a phase modifier. Because of slow extraction kinetics of this process, extraction with multiple theoretical stages by just replacing conventional extractors into the single centrifugal extractor is difficult. Hence, we improved the dispersion of organic phase by an inner rotor made of lipophilic epoxy resin and elevating the solution temperature to lower the viscosity. Higher temperature was not appropriate from the aspect of chemical equilibrium in this process, but extraction with multiple theoretical stages was found to be possible.

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“…In this work, in order to gain deeper insight into the interplay between TC flows and deformable interfaces, we use direct numerical simulation. There are some prior numerical studies simulating the behaviour of two immiscible liquids in TC geometries (Nakase & Takeshita 2012;Verdin et al 2016;Nakase, Matsuzawa & Takeshita 2018;Franken 2020;Morenko 2021). However, compared to single-phase or particle-laden TC flows, quantitative discussions and physical insights on the two-liquid flows are still limited, and no high-fidelity numerical simulations have been reported, to the best of our knowledge.…”

Section: Introductionmentioning

confidence: 99%

Interfacial-dominated torque response in liquid–liquid Taylor–Couette flows

Hori

Ng²,

Lohse³

et al. 2023

J. Fluid Mech.

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Immiscible and incompressible liquid–liquid flows are considered in a Taylor–Couette geometry and analysed by direct numerical simulations coupled with the volume-of-fluid method and a continuum surface force model. The system Reynolds number $Re \equiv r_i \omega _i d / \nu$ is fixed to $960$ , where the single-phase flow is in the steady Taylor vortex regime, whereas the secondary-phase volume fraction $\varphi$ and the system Weber number $We \equiv \rho r_i^2 \omega _i^2 d / \sigma$ are varied to study the interactions between the interface and the Taylor vortices. We show that different Weber numbers lead to two distinctive flow regimes, namely an advection-dominated regime and an interface-dominated regime. When $We$ is high, the interface is easily deformed because of its low surface tension. The flow patterns are then similar to the single-phase flow, and the system is dominated mainly by advection (advection-dominated regime). However, when $We$ is low, the surface tension is so large that stable interfacial structures with sizes comparable to the cylinder gap can exist. The background velocity field is modulated largely by these persistent structures, thus the overall flow dynamics is governed by the interface (interface-dominated regime). The effect of the interface on the global system response is assessed by evaluating the Nusselt number $Nu_{\omega }$ based on the non-dimensional angular velocity transport. It shows non-monotonic trends as functions of the volume fraction $\varphi$ for both low and high $We$ . We explain how these dependencies are closely linked to the velocity and interfacial structures.

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Numerical and Experimental Study on Oil-water Dispersion in New Countercurrent Centrifugal Extractor

Cited by 15 publications

References 6 publications

On droplets size distribution in a pulsed column. Part I: In-situ measurements and corresponding CFD–PBE simulations

On droplets size distribution in a pulsed column. Part I: In-situ measurements and corresponding CFD–PBE simulations

Multi-staging for extraction of cesium from nitric acid by a single liquid–liquid countercurrent centrifugal extractor with Taylor vortices

Interfacial-dominated torque response in liquid–liquid Taylor–Couette flows

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