Investigation of Gas Hold up and Power Consumption in a Stirred Tank Bioreactor Using Single and Dual Impeller Configurations
-
ALI KARIMI
,
FARIDEH GOLBABAEI
,
MOHAMMADREZA MEHRNIA
,
KAZEM MOHAMMAD
,
MASOUD NEGHAB
,
AHMAD NIKPEY
,
MOHAMMADREZA POURMAND
Abstract
A laboratory stirred tank bioreactor with six single and dual-impeller configurations was tested to obtain the optimum operating conditions for future biological processes. Six impeller combinations consisting of three basic impeller types, namely Rushton turbine (RT), pitched 4blade (P4B) and pitched 2blade (P2B) downward flow were investigated in 1.77 L bioreactor working volume. Power consumption and gas hold-up measurements were taken over a range of 100-1000 rpm of stirring speed and 1-5 Lmin-1 of air flowrates, for all the six combinations consisting of any single and dual impellers. Using predicted data some empirical correlations were derived which present relations in estimation of power consumption in stirred tanks with various impeller configurations. Electrical measurement method was use to determine the power drown in the stirred bioreactor. Gas hold-up increased with an increase in stirring speed and superficial gas velocity for all the impellers employed. The number and type of impellers in stirred bioreactor had considerable influence on gas hold-up behavior of the stirred bioreactor. Besides, Rushton turbine-dual Impeller gave comparably maximum gas hold-up, but at significantly higher power consumption levels. The proposed correlations offered good agreement with theexperimental data.
Taghavi M, Moghaddas J, Moghaddas Y. Experimental and CFD investigation of power consumption in adual Rushton turbine stirred tank. Chem Eng Res Des 2010; 89(3): 280-290.
Sanchez A, Martinez A, Torres L, Galindo E. Power-Consumption of 3 Impeller Combinations in Mixing Xanthan Fermentation Broths. Process Biochem 1992; 27(6): 351-365.
Khare AS, Niranjan K. An experimental investigation into the effect of impeller design on gas hold-up in a highly viscous Newtonian liquid. Chem Eng Sci 1999; 54(8): 1093-1100.
Pinelli D, Bakker A, Myers K J, Reeder MF, Fasano J, Magelli F. Some features of a novel gas dispersion impeller in a dual-impeller configuration. Chem Eng Res Des 2003; 81(A4): 448-454.
Bouaifi M, Roustan M. Power consumption, mixing time and homogenisation energy in dual-impeller agitated gas-liquid reactors. Chem Eng Process 2001; 40(2): p. 87-95.
Garcia-Ochoa F, Gomez E. Bioreactor scale-up and oxygen transfer rate in microbial processes: An overview. Biotechnol Adv 2009; 27(2): 153-176.
Khare AS, Niranjan K. The effect of impeller design on gas hold-up in surfactant containing highly viscous non-Newtonian agitated liquids. Chem Eng Process 2002; 27(2): 239-249.
Moucha T, Linek V, Prokopova E. Gas hold-up, mixing time and gas-liquid volumetric mass transfer coefficient of various multiple-impeller configurations: Rushton turbine, pitched blade and techmix impeller and their combinations. Chem Eng Sci 2003; 58(9):1839-1846.
Dohi N, Matsuda Y, Itano N, Shimizu K, Minekawa K, Kawase Y. Mixing characteristics in slurry stirred tank reactors with multiple impellers. Chem Eng Commun 1999; 171: 211-229.
Saravanan K, Patwardhan AW, Joshi JB. Critical impeller speed for solid suspension in gas inducing type mechanically agitated contactors. Can J Chem Eng 1997; 75(4): 664-676.
Harvey AD, Wood SP, Leng DE. Experimental and computational study of multiple impeller flows. Chem Eng Sci 1997; 52(9): 1479-1491.
Ascanio G, Castro B, Galindo E. Measurement of power consumption in stirred vessels - A review. Chem Eng Res Des 2004; 82(A9): 1282-1290.
Arjunwadkar SJ, Saravanan K, Pandit AB, Kulkarni PR. Optimizing the impeller combination for maximum hold-up with minimum power consumption. Biochem Eng J 1998; 1(1): 25-30.
Bouaifi MI, Roustan M. Bubble size and mass transfer coefficients in dual-impeller agitated reactors. Can J Chem Eng 1998; 76(3): 390-397.
Puthli MS, Rathod VK, Pandit AB. Gas-liquid mass transfer studies with triple impeller system on a laboratory scale bioreactor. Biochem Eng J 2005; 23(1): 25-30.
Fujasova M, Linek V, Moucha T. Mass transfer correlations for multiple-impeller gas-liquid contactors. Analysis of the effect of axial dispersion in gas and liquid phases on "local" k (L) a values measured by the dynamic pressure method in individual stages of the vessel. Chem Eng Sci 2007; 62(6): 1650-1669.
Chisti MY, Mooyoung M. Hydrodynamics and Oxygen-Transfer in Pneumatic Bioreactor Devices. Biotechnol Bioeng 1988; 31(5): 487-494.
Asgharpour M, Mehrnia MR, Mostoufi N. Effect of surface contaminants on oxygen transfer in bubble column reactors. Biochem Eng J 2011; 49(3): 351-360.
Shewale SD, Pandit AB. Studies in multiple impeller agitated gas-liquid contactors. Chem Eng Sci 2006; 61(2): 489-504.
Zhang LF, Pan QM, Rempel GL. Liquid phase mixing and gas hold-up in a multistage-agitated contactor with co-current upflow of air/viscous fluids. Chem Eng Sci 2006; 61(18): 6189-6198.
| Files | ||
| Issue | Vol 5 No 3 (2013) | |
| Section | Original Article(s) | |
| Published | 2015-10-11 | |
| Keywords | ||
| Gas hold-up Stirred bioreactor Power consumption Dual-impeller | ||
| Rights and permissions | |
|
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License. |
