Modelling of multiphase flow in packed beds by computer-assisted x-ray tomography

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.

[1]  P. Marchot,et al.  Rational description of trickle flow through packed beds part I: Liquid distribution far from the distributer , 1992 .

[2]  R. A. Brooks,et al.  Principles of computer assisted tomography (CAT) in radiographic and radioisotopic imaging , 1976, Physics in medicine and biology.

[3]  Michel Crine,et al.  Statistical hydrodynamics in trickle flow columns , 1992 .

[4]  M. Crine,et al.  Evaluation of the Performances of Random Plastic Media in Aerobic Trickling Filters , 1990 .

[5]  Sankaran Sundaresan,et al.  Onset of pulsing in two‐phase cocurrent downflow through a packed bed , 1988 .

[6]  F. Natterer,et al.  Sampling in Fan Beam Tomography , 1993, SIAM J. Appl. Math..

[7]  A. Mersmann,et al.  Mass transfer in packed columns: The cylinder model , 1993 .

[8]  Charles N. Satterfield,et al.  Trickle‐bed reactors , 1975 .

[9]  Ikeda Takashi,et al.  Preliminary Study on Application of X-Ray CT Scanner to Measurement of Void Fractions in Steady State Two-Phase Flows , 1983 .

[10]  John D. Carpinelli,et al.  CT fan beam reconstruction with a nonstationary axis of rotation , 1992, IEEE Trans. Medical Imaging.

[11]  W. Kolb,et al.  Cocurrent downflow in networks of passages. Microscale roots of macroscale flow regimes , 1990 .

[12]  F. J. Zuiderweg,et al.  Small scale and large scale liquid maldistribution in packed columns , 1986 .

[13]  Ka Ming Ng,et al.  Experimental study of reaction in trickle-bed reactors with liquid maldistribution , 1993 .

[14]  Yatish T. Shah,et al.  Gas-liquid-solid reactor design , 1979 .

[15]  K. Ng,et al.  Liquid distribution in trickle-beds. An experimental study using computer-assisted tomography , 1991 .

[16]  Apostolos Kantzas,et al.  Computation of holdups in fluidized and trickle beds by computer-assisted tomography , 1994 .

[17]  P. Marchot,et al.  Macromixing versus hydrodynamics in trickle flow columns , 1992 .

[18]  Ka Ming Ng,et al.  A novel model for reaction in trickle beds with flow maldistribution , 1990 .

[19]  P. Marchot,et al.  Interactions between the biofilm growth and the hydrodynamics in an aerobic trickling filter , 1994 .