Gas holdup and liquid circulation time were measured in a down flow jet loop reactor for air–water system. It was observed that the circulation time decreases with an increase in nozzle diameter, draft tube to column diameter ratio and liquid velocity. Th gas holdup increases with an increase in gas and liquid velocities. The optimum draft tube to column diameter ratio was found to be 0.438. Correlations for gas holdup and circulation time involving operational and geometrical variables are presented. Copyright © 1991 Canadian Society for Chemical Engineering

T. K. Ramanujam

CHEMICAL REACTORS - FLUID DYNAMICS

FLUID DYNAMICS - Mathematical Models

DOWNFLOW JET LOOP REACTORS

Flow of fluids

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

The Canadian Journal of Chemical Engineering

Experiments were conducted in a modified reversed flow jet loop reactor having the liquid outlet at the top of the reactor to determine the gas holdup and overall volumetric mass transfer coefficient in the air‐water system. The influence of gas and liquid flow rates, and the draft tube to reactor diameter ratio were studied. It was observed that both gas holdup and volumetric mass transfer coefficient increased with increased gas and liquid flow rates and were found to be significantly higher in the modified reactor compared to the conventional one. The optimum draft tube to reactor diameter ratio was found to be in the range of 0.4 to 0.5. Empirical correlations are presented to predict gas holdup and overall volumetric mass transfer coefficient in terms of operational and geometrical variables. Copyright © 1995 Canadian Society for Chemical Engineering

Gas holdup and overall volumetric mass transfer coefficient in a modified reversed flow jet loop reactor

Experiments were conducted using glass beads and low-density particles such as polyurethane and polystyrene which are comparable to bioparticles found in biological applications to evaluate the overall volumetric mass transfer coefficient (KLa) in a modified reversed flow jet loop bioreactor having the liquid outlet at the top section of the reactor. The influence of the gas and liquid flow rates, draft tube to reactor diameter ratio, solids loading and physical properties of solids on KLa were studied. The KLa was found to increase with the increased gas and liquid flow rates. The KLa values were found to be higher in the bubbly flow region i.e., at the lower range of energy dissipation rates. The optimum draft tube to reactor diameter ratio and solids loading with respect to maximum KLa were found to be 0.4 and 0.9×10-3 m3 (e{open}s=0.025) respectively. Dimensionless correlations were presented to predict the experimental values in terms of operational and geometrical variables. © 1995 Springer-Verlag.

Bioprocess Engineering

Overall volumetric mass transfer coefficient in a modified reversed flow jet loop bioreactor with low density particles

Mixing time was determined in a down-flow jet loop bioreactor with Newtonian and non-Newtonian fluids. It was observed that the mixing time decreased with an increase in linear liquid velocity, superficial gas velocity, draft tube to column diameter ratio, nozzle diameter and shear thinning of media. The optimum draft tube to column diameter ratio was found to be about 0.44. Correlations were presented for prediction of mixing time. © 1995 Springer Verlag.

Mixing time in a down-flow jet loop bioreactor

Chemical Engineering Science

Enhancement of gas-liquid mass transfer in a modified reversed flow jet loop reactor with three-phase system

Effect of low density particles on the apparent liquid circulation velocity and overall gas holdup was studied in a modified reversed flow jet loop bioreactor. Experiments were conducted using polyurethane beads, polystyrene particles which are comparable to bioparticles found in biological applications and glass beads. Influence of gas and liquid flow rates, draft tube to reactor diameter ratio and solids loading on these hydrodynamic properties were studied. The liquid circulation velocity was found to increase with an increase in liquid flow rate but decrease with an increase in gas flow rate or solids loading. The overall gas holdup increased with an increase in gas or liquid flow rate but decreased with an increase in solids loading. The range of optimum draft tube to reactor diameter ratio was found to be 04-0.5. The results obtained with low density particles were comparatively better than those with glass beads. Correlations were proposed to evaluate liquid circulation velocity and overall gas holdup in terms of operational and geometrical variables. © 1994 Springer-Verlag.

Journal	The Canadian Journal of Chemical Engineering
ISSN	00084034
Open Access	No