[en] The high resolution which can be obtained by computer-assisted x-ray tomography is used to investigate Various scale heterogeneities of the flow texture characterizing multiphase flow in packed beds. The direct counting of 'irrigated' pixels allows the determination of the number of individual liquid rivulets as well as their size. The evolution of the liquid flow texture versus the liquid velocity agrees quite well with the predictions of a percolation-based model. This agreement is further confirmed by the comparison of the experimental hold-up values averaged over the column cross-section with the theoretical model.
Disciplines :
Chemical engineering
Author, co-author :
Toye, Dominique ; Université de Liège - ULiège > Département de chimie appliquée > Génie de la réaction et des réacteurs chimiques
Marchot, Pierre ; Université de Liège - ULiège > Département de chimie appliquée > Génie chimique - Systèmes polyphasiques
Crine, Michel ; Université de Liège - ULiège > Département de chimie appliquée > Génie chimique - Opérations physiques unitaires
L'Homme, Guy ; Université de Liège - ULiège > Services généraux (Faculté des sciences appliquées) > Relations académiques et scientifiques (Sciences appliquées)
Language :
English
Title :
Modelling of multiphase flow in packed beds by computer-assisted x-ray tomography
Atkinson B and Ali A R 1976 Wetted area, slime thickness and liquid-phase mass transfer in packed bed biological film reactors (trickling filters) Trans. Inst. Chem. Eng. 54 239
Billet R 1995 Packed Towers in Processing and Environmental Technology (Weinheim: VCH)
Bornhutter K and Mersmann A 1993 Mass transfer in packed columns: the cylinder model Chem. Eng. Technol. 16 46-57
Brooks R A and Di Chiro G 1976 Principles of computer assisted tomography Phys. Med. Biol. 21 689-732
Charpentier J C, Prost C and Le Goff P 1968 Ecoulement ruisselant de liquide dans une colonne à garnissage. Détermination des vitesses et des débits relatifs des films, filets et gouttes Chim. Ind.-Génie Chim. 100 653
Charpentier J C, Prost C, van Swaaij W and Le Goff P Etude de la rétention de liquide dans une colonne à garnissage arrosé à co-courant et à contre-courant de gaz-liquide. Représentation de sa texture par un modèle à films, filets et gouttes Chim. Ind.-Génie Chim. 99 803
Concepcion J A and Carpinelli J D 1992 CT fan beam reconstruction with a nonstationary axis of rotation IEEE Trans. Med. Imaging MI-11 111-16
Crine M, Marchot P, Lekhlif B and L'Homme G 1992 Macromixing versus hydrodynamics in trickle flow columns Chem. Eng. Sci. 47 2263-8
Crine M, Marchot P and L'Homme G 1992 Statistical hydrodynamics in trickle flow columns AIChE J. 38 136-47
Crine M, Schlitz M and Vandevenne L 1990 Evaluation of the performances of random plastic media in aerobic trickling filters Water Sci. Technol. 22 227-38
Funk G A, Harold M P and Ng K M 1990 A novel model for reaction in trickle bed with flow maldistribution Ind. Eng. Chem. Res. 29 738-48
Grosser K, Carbonell R G and Sundaresan S 1988 Onset of pulsing in two-phase cocurrent downflow through a packed bed AIChE J. 34 1850-60
Hoek P J 1986 Small-scale and large-scale liquid maldistribution in packed columns Chem. Eng. Res. Des. 64 431
Ikeda T, Kotani K, Maeda Y and Kohno H 1983 Preliminary study on application of x-ray CT scanner to measurement of void fractions in steady state two-phase flows J. Nucl. Sci. Technol. 20 1-12
Kak A C and Slaney M 1988 Principles of Computerized Tomographic Imaging (New York: IEEE)
Kantzas A 1994 Computation of holdups in fluidized and trickle beds by computer-assisted tomography AIChE J. 40 1254-61
Lekhlif B, Toye D, Marchot P and Crine M 1994 Interactions between the biofilm growth and the hydrodynamics in an aerobic trickling filter Water Sci. Technol. 29 423-30
Lutran P G, Ng K M and Delikat E P 1991 Liquid distribution in trickle beds. An experimental study using computer assisted tomography Ind. Eng. Chem. Res. 30 1270
Marchot P, Crine M and L'Homme G 1992 Rational description of trickle flow through packed beds. Part I: liquid distribution far from the distributor Chem. Eng. J. 48 49-59
Marchot P, Crine M and L'Homme G 1992 Rational description of trickle flow through packed beds. Part II: radial spreading of the liquid Chem. Eng. J. 48 61-70
McManus R L, Funk G A, Harold M P and Ng K M 1993 Experimental study of reaction in trickle bed with liquid maldistribution Ind. Eng. Chem. Res. 32 570-4
Melli T R, de Santos J M, Kolb W B and Scriven L E 1990 Cocurrent downflow in networks of passages. Microscale roots of macroscale flow regimes Ind. Eng. Chem. Res. 29 2367-79
Natterer F 1993 Sampling in fan beam tomography SIAM J. Appl. Math. 53 358
Satterfield C N 1975 Trickle-bed reactors AIChE J. 21 209
Shah Y T 1979 Gas-Liquid-Solid Reactor Design (New York: McGraw-Hill)
Stikkelman R M 1989 Gas and liquid maldistributions in packed columns PhD Thesis Technische Universiteit of Delft
Zuiderweg F J and Hoek P J 1987 The effect of small scale maldistribution ('natural flow') on the separating efficiency of random packing Inst. Chem. Eng. Symp. Series 104 pp B247-B254