Effect of Superficial Gas Velocity on Bubble Size, Terminal Bubble Rise Velocity and Gas Hold‐up in Bubble Columns

It is important to have a reliable estimate of bubble size, terminal bubble rise velocity and gas hold-up in bubble columns, since these parameters are directly related to the transfer coefficients and the transfer area. Mean bubble diameters have been measured as a function of the superficial gas velocity in air-water systems. In the bubbly flow regime, the bubble size is a strong function of the orifice diameter and the wettability of the gas distributor and a weak function of superficial gas velocity. In the turbulent churn flow regime this functionality is reversed and the bubble diameter becomes a strong function of the superficial gas velocity. A correlation is presented which covers both regimes. The terminal bubble rise velocity was measured as a function of the bubble size and the results were compared with correlations recommended in the literature. Finally, the gas hold-up was measured over a wide range of superficial gas velocities. The results were compared with a variety of empirical and theoretical correlations. New equations are presented which predict gas hold-up of the air-water system with good accuracy.

[1]  R. Sinn,et al.  Stoffaustauschfläche und Energiedissipationsdichte als Auswahlkriterien für Gas/Flüssigkeits‐Reaktoren Teil I: Die Stoffaustauschfläche in verschiedenen Gas/Flüssigkeits‐Reaktoren als Funktion der Betriebsparameter , 1972 .

[2]  Kiyomi Akita,et al.  Bubble Size, Interfacial Area, and Liquid-Phase Mass Transfer Coefficient in Bubble Columns , 1974 .

[3]  K. Schügerl,et al.  Bubble column bioreactors , 2004, European journal of applied microbiology and biotechnology.

[4]  S. Sideman,et al.  MASS TRANSFER IN GAS-LIQUID CONTACTING SYSTEMS , 1966 .

[5]  J. H. Hills,et al.  The operation of a bubble column at high throughputs: I. Gas holdup measurements , 1976 .

[6]  Leon Lapidus,et al.  The mechanics of vertical gas‐liquid fluidized system I: Countercurrent flow , 1964 .

[7]  J. J. J. Chen,et al.  Effect of liquid depth on circulation in bubble columns: a visual study , 1989 .

[8]  William L. Haberman,et al.  An Experimental Study of Bubbles Moving in Liquids , 1956 .

[9]  Jyeshtharaj B. Joshi,et al.  Axial mixing in multiphase contactors - a unified correlation , 1980 .

[10]  A kinetic model for methanol conversion to hydrocarbons , 1981 .

[11]  G. Marrucci.  Communication. Rising Velocity of Swarm of Spherical Bubbles , 1965 .

[12]  Takashi Akehata,et al.  BEHAVIOR OF BUBBLES IN LARGE SCALE BUBBLE COLUMN , 1979 .

[13]  W. Deckwer,et al.  A comprehensive study on co2‐interphase mass transfer in vertical cocurrent and countercurrent gas‐liquid flow , 1978 .

[14]  Leon Lapidus,et al.  Mechanics of vertical‐moving fluidized systems , 1957 .

[15]  Irving Leibson,et al.  Rate of flow and mechanics of bubble formation from single submerged orifices. I. Rate of flow studies , 1956 .

[16]  Hiroshi Takeuchi,et al.  MASS TRANSFER IN A LARGE BUBBLE COLUMN , 1979 .

[17]  Kiyomi Akita,et al.  Gas Holdup and Volumetric Mass Transfer Coefficient in Bubble Columns. Effects of Liquid Properties , 1973 .

[18]  J. R. Fair,et al.  Heat Transfer and Gas Holdup in a Sparged Contactor , 1962 .

[19]  H. Unno,et al.  Size reduction of bubbles by orifice mixer , 1980 .

[20]  S. Saxena,et al.  Bubble size distribution in bubble columns , 1990 .

[21]  S. B. Sawant,et al.  Hydrodynamics and mass transfer characteristics of packed bubble columns , 1990 .

[22]  J. Davidson,et al.  The behaviour of a continuously bubbling fluidised bed , 1966 .

[23]  M. Rosen,et al.  MATHEMATICAL MODELING OF FISCHER- TROPSCH SLURRY BUBBLE COLUMN REACTORS , 1986 .

[24]  S. Asai,et al.  Gas hold-up in bubble columns , 1980 .

[25]  K. Westerterp,et al.  Interfacial Areas and Gas Hold-ups in Bubble Columns and Packed Bubble Columns at Elevated Pressures , 1989 .

[26]  W. Weiss,et al.  Flüssigkeitsdurchmischung in engen Blasensäulen , 1957 .

[27]  Otto Nagel,et al.  Kriterien für die Auswahl und die Auslegung von Gas/Flüssigkeits‐Reaktoren , 1978 .

[28]  Herbert Kölbel,et al.  Dynamische Messung des relativen Gasgehaltes in Blasensäulen mittels Absorption von Röntgenstrahlen , 1972 .

[29]  J. Kubie.  Size reduction of bubbles by orifice mixers , 1981 .

[30]  J.C.R. Turner.  On bubble flow in liquids and fluidised beds , 1966 .

[31]  R. Kumar,et al.  The Formation of Bubbles and Drops , 1970 .

[32]  C. Satterfield,et al.  Reply to letters of Bukur and Gupte and of van Vuuren concerning mass transfer limitations in Fischer-Tropsch slurry reactors , 1981 .

[33]  Yatish T. Shah,et al.  Design parameters estimations for bubble column reactors , 1982 .

[34]  D. Cova,et al.  Longitudinal Mixing in Gas-Sparged Tubular Vessels , 1965 .