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Journal ArticleDOI

Influence of plate geometry and added packing on dispersed phase holdup and slip velocity in reciprocating plate column

01 Dec 1997-Bioprocess Engineering (Springer-Verlag)-Vol. 18, Iss: 1, pp 63-70
TL;DR: In this article, a comprehensive study of the influence of plate geometry and the added packing on the holdup and slip velocity in reciprocating plate columns is presented, and the use of packing in the interplate spaces of the column is of interest as packing alters the character of dispersion and also provides contact area for the phases.
Abstract: A comprehensive study of the influence of plate geometry and the added packing on the holdup and slip velocity in reciprocating plate columns is presented. The use of packing in the interplate spaces of the column is of interest as packing alters the character of dispersion and also provides contact area for the phases.
Citations
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Journal ArticleDOI
TL;DR: In this article, the effects of agitation speed, dispersed and continuous phase flow rates, interfacial tension and mass transfer on slip velocity have been investigated under a variety of operating conditions and two empirical correlations for prediction of the slip velocity within mixer and through the column are recommended in terms of physical properties of liquid systems and operating variables excluding holdup.
Abstract: Slip velocity within mixer and through the column has been measured in a pilot plant Hanson mixer-settler column by using three different liquid–liquid systems with and without mass transfer conditions. The effects of agitation speed, dispersed and continuous phase flow rates, interfacial tension and mass transfer on slip velocity have been investigated under a variety of operating conditions. Two empirical correlations for prediction of the slip velocity within mixer and through the column are recommended in terms of physical properties of liquid systems and operating variables excluding holdup. The prediction of slip velocities from the presented correlations is in good agreement with experimental results. La vitesse de glissement a l'interieur du melangeur et dans la colonne a ete mesuree dans une colonne de melangeur-decanteur Hanson en installation pilote en utilisant trois systemes liquide-liquide differents avec et sans conditions de transfert de masse. Les effets de la vitesse d'agitation, des taux d'ecoulement des phases dispersees et continues, de la tension interfaciale et du transfert de masse sur la vitesse de glissement ont ete etudies sous une variete de conditions de fonctionnement. Deux correlations empiriques pour la prediction de la vitesse de glissement a l'interieur du melangeur et dans la colonne sont recommandees en termes de proprietes physiques des systemes liquides et de variables de fonctionnement excluant la retenue. La prediction des vitesses de glissement a partir des correlations presentees s'accorde tout a fait avec les resultats experimentaux. Can. J. Chem. Eng. © 2010 Canadian Society for Chemical Engineering

13 citations

References
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Journal ArticleDOI
TL;DR: In this article, the Sauter mean droplet diameter was found to depend on the product of plate amplitude and frequency and on the system properties, but it was not in general affected by the throughput.

85 citations


"Influence of plate geometry and add..." refers background in this paper

  • ...Figure ( 7 ) compares the experimental slip velocity (Eq. 1a) with the prediction using Eq. (19)....

    [...]

  • ...Noting that the drop diameter d32 in pulsed columns depends on the specific power dissipation w ( 7 ):...

    [...]

Journal ArticleDOI
TL;DR: In this article, the authors measured oxygen absorption from air into water and axial dispersion in the aqueous phase in a 5 cm diameter reciprocating plate bubble column and found that axial mixing had little effect and conditions approached plug flow.
Abstract: Oxygen absorption from air into water and axial dispersion in the aqueous phase have been measured in a 5 cm diameter reciprocating plate bubble column. The volumetric mass transfer coefficients in semi-batch conditions were found to increase with agitation and were correlated with the specific power input and air flow rate. Under countercurrent conditions, it was found that axial mixing had little effect and conditions approached plug flow. The volumetric mass transfer coefficients were correlated with specific power input, air and water flow rates. Mass transfer coefficients were estimated using holdup and bubble diameter results. Comparison of the coefficients with the literature values indicated that the bubble surfaces were partially mobile. On a mesure l'absorption de l'oxygene de l'air dans l'eau et la dispersion axiale dans la phase aqueuse dans une colonne a bulles a plateaux reciproques de 5 cm de diametre. On a trouve que les coefficients de transfert de matiere volumetriques dans des conditions semi-continues augmentent avec l'agitation; ces coefficients ont ete correles avec l'apport d'energie specifique et le debit d'air. On a montre qu'a contre-courant, le melange axial a peu d'effet et que l'on se rapproche des conditions d'ecoulement piston. Les coefficients de transfert de matiere volumetriques obtenus dans ce cas ont ete correles en fonction de l'apport d'energie specifique, du debit d'eau et du debit d'air. On a estime les coefficients de transfert de matiere a l'aide des diametres des bulles et la retention. La comparaison des coefficients avec les valeurs publiees indiquent que la surface des bulles est partiellement mobile.

51 citations


"Influence of plate geometry and add..." refers background in this paper

  • ...(3) and (4), it is noted that Eq. ( 3 ) does not agree with the data obtained using high free area plates (S > 0:5), while Eq. (4) is satisfactory only to the data obtained using plates of high free area....

    [...]

  • ...(1) refers to no mass transfer between phases; (2) refers to benzoic acid as solute (d-c) ( 3 ) refers to n-butyric acid as solute (d-c); (4) refers to n-butyric acid as solute (c-d) (5) refers to acetone as solute for toluene (d)-water (c) system (d-c)...

    [...]

  • ...( 3 ) and (4), it is noted that Eq. (3) does not agree with the data obtained using high free area plates (S > 0:5), while Eq. (4) is satisfactory only to the data obtained using plates of high free area....

    [...]

  • ...Lo et al. (2), Baird and Ramarao ( 3 ) reviewed the development and application of reciprocating plate columns....

    [...]

Journal ArticleDOI
TL;DR: In this article, it has been shown that the Reynolds number relationship for a single spherical solid particle may be applied to multi-particle systems as well, provided that modified definitions of the drag coefficient and Reynolds number incorporating suitable functions of the particles volume fraction are used.
Abstract: In a recently published paper(1), it has been demonstrated that the drag coefficient—Reynolds number relationship for a single spherical solid particle may be applied to multi-particle systems as well, provided that modified definitions of the drag coefficient and Reynolds number incorporating suitable functions of the particles volume fraction are used. This generalised approach is now extended to include the case of a fluid dispersed phase. This done by incorporating a function of the ratio of the phase viscosities, based on theoretical derivations due to Hadamard—Rybczinski and Taylor in the modified definition of Reynolds number. All available experimental data (88 points from 3 sources, on 12 different liquid-liquid systems) were recalculated and correlated on this basis. On a demontre, dans un travail publie recemment(1), qu'on peut appliquer egalement a des systemes de particules multiples la relation entre le coefficient de resistance a la traǐnee et le nombre de Reynolds qui s'adresse a une seule particule solide et spherique, pourvu qu'on emploie des definitions modifiees du coefficient de resistance a la traǐnee et du nombre de Reynolds qui incorporent des fonctions appropriees de la fonction du volume des particules. On fait une extension de ce mode d'approche generalise de maniere qu'il embrasse le cas d'une phase de fluide disperse; on y parvient en incorporant une fonction du rapport des viscosites de la phase, laquelle est basee sur des deductions theoriques faites par Hadamard, Rybczinski et Taylor dans une definition modifiee du nombre de Reynolds. On a recalcule tous les resultats experimentaux qui etaient disponibles (88 points provenant de 3 ponces dans le cas de 12 systemes differents et impliquant divers liquides) et etabli, sur cette base, des correlations entre ceux-ci.

43 citations


"Influence of plate geometry and add..." refers methods in this paper

  • ...This has been considered by number of investigators ( 12 ) through modelling and experiment and was given as:...

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Journal ArticleDOI
TL;DR: Mise en place de correlations for le calcul de la retenue de la phase dispersee and de la vitesse d'engorgement a partir de donnees experimentales and de modeles fournis dans la litterature.
Abstract: Mise en place de correlations pour le calcul de la retenue de la phase dispersee et de la vitesse d'engorgement a partir de donnees experimentales et de modeles fournis dans la litterature. Ces equations sont etablies dans le cas ou il y a transfert de matiere mais aussi lorsque celui-ci est absent

37 citations

Journal ArticleDOI
TL;DR: In this paper, a simplified predictive model for holdup and flooding conditions in a 5 cm diameter reciprocating plate extraction column was developed assuming uniform hydrodynamic conditions throughout the column, which was confirmed for several systems but may be limited in application by the following factors: (a) mass transfer, particularly from dispersed to continuous phase (coalescence effect), (b) wettability of plates by dispersed phase, axial non-uniformity of holdup (noticed particularly for high interfacial tension systems), (d) the use of exceptionally high frequencies or low ampl
Abstract: Measurements of dispersed phase holdup and flooding conditions have been carried out in a 5 cm diameter reciprocating plate extraction column. A simplified predictive model for holdup and flooding has been developed assuming uniform hydrodynamic conditions throughout the column. The model has been confirmed for several systems but may be limited in application by the following factors: (a) mass transfer, particularly from dispersed to continuous phase (coalescence effect), (b) wettability of plates by dispersed phase, (c) axial non-uniformity of holdup (noticed particularly for high interfacial tension systems), (d) the use of exceptionally high frequencies or low amplitudes of agitation. On a determine la retention de la phase dispersee et les conditions de l'engorgement dans une colonne d'extraction a plateau alternatif de 5 cm de diametre. On a etabli un modele simple pour prevoir la retention et l'engorgement, en supposant l'existence de conditions hydrodynamiques uniformes d'un bout a l'autre de la colonne. On a confirme l'utilite du modele pour plusieurs systemes, mais les facteurs suivants peuvent limiter son application: (a) le transfert de masse, particulierement celui de la phase dispersee a la phase continue (effet de coalescence); (b) le mouillage des plateaux par la phase dispersee; (c) absence d'uniformite axiale de la retention (observee surtout dans le cas des systemes a tension interfaciale elevee); (d) emploi de frequences exceptionnellement elevees ou d'amplitudes d'agitation faibles.

34 citations