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1

Energetic efficiency of mass transfer accompanied by chemical reactions in liquid-liquid systems

Jasińska M., Bałdyga J.

Chemical and Process Engineering

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2017

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Vol. 38, nr 3

433--444

EN

Energetic efficiency depicting the fraction of energy dissipation rate used to perform processes of drop breakup and mass transfer in two-phase, liquid-liquid systems is considered. Results of experiments carried out earlier in two types of high-shear mixers: an in-line rotor-stator mixer and a batch rotor-stator mixer, have been applied to identify and compare the efficiency of drop breakage and mass transfer in both types of mixers. The applied method is based on experimental determination of both: the product distribution of chemical test reactions and the drop size distributions. Experimental data are interpreted using a multifractal model of turbulence for drop breakage and the model by Favelukis and Lavrenteva for mass transfer. Results show that the energetic efficiency of the in-line mixer is higher than that of the batch mixer; two stator geometries were considered in the case of the batch mixer and the energetic efficiency of the device equipped with a standard emulsor screen (SES) was higher than the efficiency of the mixer equipped with a general purpose disintegrating head (GPDH) for drop breakup but smaller for mass transfer.

2

Application of new chemical test reactions to study mass transfer from shrinking droplets and micromixing in the rotor-stator mixer

Bałdyga J., Kotowicz M.

Chemical and Process Engineering

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2017

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Vol. 38, nr 3

477--489

EN

A pair of fast competitive reactions, neutralization and 2,2-dimetoxypropane (DMP) hydrolysis, has been applied do study mass transfer and micromixing in a T 50 Ultra-Turrax® - IKA rotor-stator device. In experiments the dispersed organic phase containing p-Toluenesulfonic acid (pTsOH) dissolved in diisopropyl ether, whereas the continuous phase was represented by the aqueous solution of sodium hydroxide, 2,2-dimetoxypropane (DMP) and ethanol. During mixing a fast mass transfer of a solute (pTsOH) from organic phase droplets, which were shrinking due to fast dissolution of the organic solvent, was followed by micromixing and chemical reactions in the continuous phase. Measured hydrolysis yields were applied to express effects of mixing on the course of chemical reactions. Modeling was based on application of models describing drop breakup, mass transfer in the liquid-liquid system and micromixing. Combined effects of mass transfer and drop breakage on drop population were expressed using the population balance equations. The model has been used to interpret experimental results, in particular to identify the efficiency of mixing.

3

Dyspersja kropel w mieszalnikach typu rotor-stator

Jasińska M., Bałdyga J., Hall S., Pacek A.

Inżynieria i Aparatura Chemiczna

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2013

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Nr 3

187--188

PL

Przedstawiona praca ma charakter doświadczalno-teoretyczny. W części doświadczalnej przeprowadzono badania rozpadu rozproszonych w wodzie kropel oleju silikonowego. Badania prowadzono w przepływowym mieszalniku typu rotor-stator (Silverson), pracującym w sposób ciągły. Modelowanie prowadzono wykorzystując oprogramowanie CFD i multifraktalny model burzliwości. Wyniki obliczeń pokazały zgodność trendów z wynikami doświadczalnymi.

EN

The work deals with numerical and experimental investigations of drop breakup during the formation of emulsions. Silicon oil was applied to investigate drop dispersion in the in-line Silverson rotor-stator mixer. Experimental results were interpreted using CFD and the multifractal model oi intermittent turbulence. Predicted trends of influence of process parameters on drop size agree with experimental data.