Abstract
Liquid-side mass-transfer coefficients (KLa) were measured in air-suction type fermentors using physical absorption of oxygen. A fermentor of 0. 5 m i.d. was used with a working capacity of 60 liters of liquid. Tap water was used as the liquid phase, and air was used as the gas phase. The bioreactor mixing system consists of shrouded-disk/curved-blade turbine with six evacuated bending blades. The effect of liquid submergence (S) was investigated. Further, the effects of the ratio of the impeller diameter (D) to the tank diameter (T), and the clearance of the impeller from the tank bottom(C) were also studied. The agitation speed (N) was varied in the range of 50-800 rpm. It was found that the value of KLa increased as the impeller diameter increased, while it was decreased continuously with increasing the clearance. the effect of impeller submergence on the value of mass transfer coefficient (KLa) is not much pronounced.
Suitable correlation was developed for estimating mass transfer coefficient (KLa) in this type of bioreactors.
References
Fuchs, R.; Ryu, D. D.; Humphrey, A. E. ( 1971) Effect of Surface Aeration on Scale-up Procedures for Fermentation Process. Ind. Eng. Chem. Process Des. Dev., 10, 190.
Matsumura, M.; Sakuma, H.; Yamagata, T.; Kobayashi, J. (1982) Performance of Oxygen Transfer in a New Gas Entraining Fermentor. J. Ferment. Technol., 60, 551.
Ognean, T.(1993) Dimensionless Criteria for Estimating Oxygen Transfer in Aeration System. Biotechnol. Bioeng. , 41, 1014.
Ognean, T. (1997) Relationship Between Oxygen Mass Transfer Rate and Power Consumption by Vertical Shaft Aerator. WaterRes, 31, 1332.
Patil, S. S.; Joshi, J. B. (1999) Stability of Gas Inducing Type Impellers. Can. J. Chem. Eng., 55, 793.
Patil, S. S.; Joshi, J. B. (2004) Mass transfer characteristics of surface Aerators impellers. Ind. Eng. Res. 43, 2765.
Patil, S. S.; Joshi, J. B. (2003) Optimum design of Multible Impellers system. Ind. Eng. Res. 42,1261.
Shukla, V.B.; Veera, U.P.; Kulkarni,P.R.; Pandit, A.B.(2001) Scale- up of bioreactor process in stirred tank reactor using dual impeller bioreactor. Biochemical Engineering journal. 8, 19.
Takase, H.; Unno, H.; Akehata, T. (1984) Oxygen Transfer in a Surface Aeration Tank with Square Cross Section. Int. Chem. Eng., 21, 128.
Wu, H. (1995) An Issue on Applications on Applications of a Disk Turbine for Gas-Liquid Mass Transfer. Chem. Eng. Sci., 50, 668.
Zlokarnik, M. (1979) Scale-up of Surface Aerators for Wastewater Treatment. Adv. Biochem. Eng., 11, 157.
Copyright: Open Access authors retain the copyrights of their papers, and all open access articles are distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution and reproduction in any medium, provided that the original work is properly cited. The use of general descriptive names, trade names, trademarks, and so forth in this publication, even if not specifically identified, does not imply that these names are not protected by the relevant laws and regulations. While the advice and information in this journal are believed to be true and accurate on the date of its going to press, neither the authors, the editors, nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein.