Liquid velocity and gas holdup in three-phase internal loop airlift reactors with low-density particles

Abstract Liquid velocity and gas holdup in three-phase internal loop airlift reactors were investigated. Air and water were used as the gas and liquid phase, respectively, and the solid particles used were calcium alginate beads with different particle size. The liquid velocity in the riser and the downcomer were obtained by tracer analysis. The gas holdup in the riser and the downcomer were determined by manometric technique. It was found that the liquid velocity did not show any significant variations with top clearance. The liquid velocity increased with an increase in aeration rate or draught tube length, whereas it decreased as the diameter of the particles was increased. Moreover, the liquid velocity and the gas holdup decreased with increasing solids loading. A hydrodynamic model based on the drift-flux model was developed to describe satisfactorily the liquid velocity and gas holdup in air-water-calcium alginate internal loop airlift reactors.

[1]  J. Tramper,et al.  Hydrodynamics, axial dispersion and gas-liquid oxygen transfer in an airlift-loop bioreactor with three-phase flow. , 1987 .

[2]  R.L.C. Flemmer,et al.  Predicting the holdup in two‐phase bubble upflow and downflow using the Zuber and Findlay drift‐flux model , 1985 .

[3]  Andrew G. Livingston,et al.  Hydrodynamic behaviour of three-phase (gas—liquid—solid) airlift reactors , 1993 .

[4]  P. Letón,et al.  A fluid dynamic model for bubble columns and airlift reactors , 1991 .

[5]  G. Vunjak‐Novakovic,et al.  Flow regimes and liquid mixing in a draft tube gas-liquid-solid fluidized bed , 1992 .

[6]  G. Wallis.  One Dimensional Two-Phase Flow , 1969 .

[7]  M. Moo-Young,et al.  Liquid circulation in airlift reactors , 1988 .

[8]  Hiroshi Kubota,et al.  LIQUID CIRCULATION, GAS HOLDUP AND PRESSURE DROP IN BUBBLE COLUMN WITH DRAUGHT TUBE , 1984 .

[9]  E.Garcia Calvo.  A fluid dynamic model for airlift loop reactors , 1989 .

[10]  A. C. Hulst,et al.  A new technique for the production of immobilized biocatalyst in large quantities , 1985, Biotechnology and bioengineering.

[11]  T. Miyahara,et al.  Hydrodynamics of a solid-suspended bubble column with a draught tube containing low-density particles , 1993 .

[12]  Jose C. Merchuk,et al.  Air‐lift reactor analysis: Interrelationships between riser, downcomer, and gas‐liquid separator behavior, including gas recirculation effects , 1986 .

[13]  J. Przywarski,et al.  An average gas hold-up and liquid circulation velocity in airlift reactors with external loop , 1993 .

[14]  Alan Jones,et al.  Liquid circulation in a draft-tube bubble column , 1985 .

[15]  David F. Ollis,et al.  Airlift bioreactors: Analysis of local two‐phase hydrodynamics , 1991 .

[16]  N. Zuber,et al.  Average volumetric concentration in two-phase flow systems , 1965 .

[17]  Dietmar C. Hempel,et al.  Hydrodynamics and local parameters in three-phase-flow in airlift-loop reactors of different scale , 1992 .

[18]  D. Karamanev,et al.  Hydrodynamic and mass transfer study of a gas-liquid-solid draft tube spouted bed bioreactor , 1992 .

[19]  J. Baeyens,et al.  Fluidization and its Applications : Proceedings of the International Symposium held in Toulouse, France, in 1973; pp. 729, £30.00. , 1976 .

[20]  Wen-Jang Lu,et al.  Liquid mixing in two- and three-phase airlift reactors , 1994 .

[21]  Milorad P. Dudukovic,et al.  18 Gas holdup and liquid recirculation in gas-lift reactors , 1980 .

[22]  Johannes Tramper,et al.  A hydrodynamic model for an airlift-loop bioreactor with external loop , 1986 .

[23]  D. R. Oliver.  The sedimentation of suspensions of closely-sized spherical particles , 1961 .

[24]  Jose C. Merchuk,et al.  Local hold‐up and liquid velocity in air‐lift reactors , 1981 .

[25]  Campbell W. Robinson,et al.  Liquid circulation and mixing characteristics of airlift contactors , 1984 .

[26]  M. Kennard,et al.  Two‐ and three‐phase mixing in a concentric draft tube gas‐lift fermentor , 1991, Biotechnology and bioengineering.