Process characteristics for a gas—liquid system agitated in a vessel equipped with a turbine impeller and tubular baffles
-
Marta Major-Godlewska
und
Joanna Karcz
Abstract
Results of the experimental research on gas hold-up, power consumption for liquid phase and gas—liquid systems, and on residence time of the gas bubbles are presented in the paper for an agitated vessel with a turbine impeller. Distilled water or aqueous solutions of NaCl were used as the liquid phase. Air was dispersed into liquid as the gas phase. The studies were carried out in an agitated vessel of the inner diameter D = 0.634 m. Tubular baffles of the diameter of 0.7D, consisting of 24 vertical tubes of the diameter of 0.016D, were located inside a flat-bottomed tank. Turbines with six blades and the pitch of 90°, 60°, or 45°, respectively, were used for agitation. Measurements were carried out in the range of good dispersion of gas bubbles in the liquid within the turbulent regime of the liquid flow. Effects of the gas bubbles capability to coalesce on the gas hold-up, residence time of the gas bubbles, and power consumption were analyzed. Results of the power consumption (P G-L/P o = f 1(Kg, Fr)) and gas hold-up (φ= f 2(Kg, We, Y)) were approximated mathematically, using Eqs. (5) and (6), respectively. In Eq. (6), parameter Y was introduced in order to describe the influence of the bubbles capability to coalesce on the gas hold-up. The results of the study show that power consumption does not depend on the capability of bubbles to coalesce, but the pitch of the turbine impeller affects the power characteristics in such a physical system significantly. However, the residence time of the gas phase in agitated liquid depends on the pitch of the impeller blade and on the capability of bubbles to coalesce.
[1] Ankamma Rao, D., & Sivashanmugam, P. (2010). Experimental and CFD simulation studies on power consumption in mixing using energy saving turbine agitator. Journal of Industrial and Engineering Chemistry, 16, 157–161. DOI: 10.1016/j.jiec.2010.01.002. http://dx.doi.org/10.1016/j.jiec.2010.01.00210.1016/j.jiec.2010.01.002Suche in Google Scholar
[2] Dunlap, I. R., & Rushton, J. H. (1953). Heat transfer coefficients in liquid mixing vertical tube baffles. Chemical Engineering Progress, 49(5), 137–151. Suche in Google Scholar
[3] Harnby, N., Edwards, M. F., & Nienow, A. W. (1997). Mixing in the process industries. Oxford, UK: Butterworth. Suche in Google Scholar
[4] Karcz, J., & Major, M. (2001a). Experimental studies of heat transfer in an agitated vessel equipped with vertical tubular coil. Inżzynieria Chemiczna i Procesowa, 22, 445–459. Suche in Google Scholar
[5] Karcz, J., & Major, M. (2001b). Heat transfer in an agitated vessel equipped with vertical tubular coil. Inżzynieria Chemiczna i Procesowa, 22, 639–644. (in Polish) Suche in Google Scholar
[6] Karcz, J., & Major, M. (1998). An effect of a baffle length on the power consumption in an agitated vessel. Chemical Engineering and Processing, 37, 249–256. DOI: 10.1016/S0255-2701(98)00033-6. http://dx.doi.org/10.1016/S0255-2701(98)00033-610.1016/S0255-2701(98)00033-6Suche in Google Scholar
[7] Karcz, J., Stręk, F., Major, M., & Michalska, M. (2002). An efficiency of the heat transfer process in an agitated vessel equipped with a vertical tubular coil. In Proceedings of the 15th International Congress CHISA, August 25–29 2002 (paper P5.150, 8 pp.). Prague, Czech Republic. Suche in Google Scholar
[8] Karcz, J., Stręk, F., Major, M., & Siciarz, R. (1998). An effect of the geometrical parameters of the tubular baffles on a power consumption in the agitated vessel. In Proceedings of the 13th International Congress CHISA, August 23–28 1998 (paper P1.29, 9 pp.). Prague, Czech Republic. Suche in Google Scholar
[9] Lee, J. C., & Meyrick, D. L. (1970). Gas-liquid interfacial areas in salt solutions in an agitated tank. Transactions of the Institution of Chemical Engineers, 48, T37–T45. Suche in Google Scholar
[10] Machoň, V., Vlček, J., & Kudrna, V. (1978). Gas hold-up in agitated aqueous solutions of strong inorganic salts. Collection of Czechoslovak Chemical Communications, 43, 593–603. 10.1135/cccc19780593Suche in Google Scholar
[11] Major, M. (2000). Studies on the heat transfer from the vertical coil to the pseudoplastic liquid stirred in a tank with the rotating agitator. PhD Thesis, Technical University of Szczecin, Szczecin, Poland. Suche in Google Scholar
[12] Major-Godlewska, M. (2003). Experimental studies of gas holdup and power consumption in an agitated vessel equipped with a vertical coil. Inżzynieria i Aparatura Chemiczna, 42(5), 125–127. (in Polish) Suche in Google Scholar
[13] Major-Godlewska, M., & Karcz, J. (2003). Gas hold-up and power consumption for gas-liquid system agitated in a stirred tank equipped with vertical coil. Chemical Papers, 57, 432–444. Suche in Google Scholar
[14] Man, K. L., Hughes, W., & Moody, G. W. (1991). The effect of rheology and baffle design on the power and heat transfer performance in stirred vessels using vertical tubular baffles. In Proceedings of the 7th European Conference on Mixing, September 18–20 1991 (Part I, pp. 321-332). Brugge, Belgium. Suche in Google Scholar
[15] Michalska, M. (2001). Heat transfer in a stirred tank equipped with the vertical tubular coil and rotating agitator. PhD Thesis, Technical University of Szczecin, Szczecin, Poland. Suche in Google Scholar
[16] Paul, E. L., Atiemo-Obeng, V. A., & Kresta, S. M. (2004). Handbook of industrial mixing. Hoboken, NJ, USA: Wiley-Interscience. Suche in Google Scholar
[17] Sivashanmugam, P., & Prabhakaran, S. (2008). Simulation of an effect of a baffle length on the power consumption in an agitated vessel. International Journal of Food Engineering, 4(2), article 3. DOI: 10.2202/1556-3758.1320. 10.2202/1556-3758.1320Suche in Google Scholar
[18] Sivashanmugam, P., & Sandeep, P. (2009). Experimental studies and CFD modeling on the effects of a cut in the baffle on power consumption. Chemical Product and Process Modeling, 4(1), article 5. DOI: 10.2202/1934-2659.1340. 10.2202/1934-2659.1340Suche in Google Scholar
[19] Stręk, F. (1981). Agitation and agitated vessels. Warsaw, Poland: WNT. (in Polish) Suche in Google Scholar
[20] Tatterson, G. B. (1991). Fluid mixing and gas dispersion in agitated tanks. New York, NY, USA: McGraw-Hill. Suche in Google Scholar
[21] Torré, J.-P., Fletcher, D. F., Lasuye, T., & Xuereb, C. (2007). An experimental and computational study of the vortex shape in a partially baffled agitated vessel. Chemical Engineering Science, 62, 1915–1926. DOI: 10.1016/j.ces2006.12.020. http://dx.doi.org/10.1016/j.ces.2006.12.020Suche in Google Scholar
[22] Zadghaffari, R., Moghaddas, J. S., & Revstedt, J. (2010). Largeeddy simulation of turbulent flow in a stirred tank driven by Rushton turbine. Computers & Fluids, 39, 1183–1190. DOI: 10.1016/j.compfluid.2010.03.001. http://dx.doi.org/10.1016/j.compfluid.2010.03.00110.1016/j.compfluid.2010.03.001Suche in Google Scholar
© 2010 Institute of Chemistry, Slovak Academy of Sciences
Artikel in diesem Heft
- Mechanisms controlling lipid accumulation and polyunsaturated fatty acid synthesis in oleaginous fungi
- Predicting retention indices of aliphatic hydrocarbons on stationary phases modified with metallocyclams using quantitative structure-retention relationships
- New SPME fibre for analysis of mequinol emitted from DVDs
- Continuous production of citric acid from raw glycerol by Yarrowia lipolytica in cell recycle cultivation
- Enhancing the production of gamma-linolenic acid in Hansenula polymorpha by fed-batch fermentation using response surface methodology
- Process characteristics for a gas—liquid system agitated in a vessel equipped with a turbine impeller and tubular baffles
- Kinetic study of pyrolysis of waste water treatment plant sludge
- Transport phenomena in an agitated vessel with an eccentrically located impeller
- Membrane extraction of 1-phenylethanol from fermentation solution
- Theoretical study on transesterification in a combined process consisting of a reactive distillation column and a pervaporation unit
- Wall effects on terminal falling velocity of spherical particles moving in a Carreau model fluid
- The effect of the physical properties of the liquid phase on the gas-liquid mass transfer coefficient in two- and three-phase agitated systems
- Effectiveness of nitric oxide ozonation
- Modelling of nanocrystalline iron nitriding process — influence of specific surface area
- Effect of CeO2 and Sb2O3 on the phase transformation and optical properties of photostable titanium dioxide
- Carnauba wax microparticles produced by melt dispersion technique
- Complexation studies of 3-substituted β-diketones with selected d- and f-metal ions
- Influence of the solvent donor number on the O/W partition ratio of Cu(II) complexes of 1,2-dialkylimidazoles
- Continuous dialysis of sulphuric acid in the presence of zinc sulphate
- Differences in affinity of arylstilbazolium derivatives to tetraplex structures
- Fast ferritin immunoassay on PDMS microchips
Artikel in diesem Heft
- Mechanisms controlling lipid accumulation and polyunsaturated fatty acid synthesis in oleaginous fungi
- Predicting retention indices of aliphatic hydrocarbons on stationary phases modified with metallocyclams using quantitative structure-retention relationships
- New SPME fibre for analysis of mequinol emitted from DVDs
- Continuous production of citric acid from raw glycerol by Yarrowia lipolytica in cell recycle cultivation
- Enhancing the production of gamma-linolenic acid in Hansenula polymorpha by fed-batch fermentation using response surface methodology
- Process characteristics for a gas—liquid system agitated in a vessel equipped with a turbine impeller and tubular baffles
- Kinetic study of pyrolysis of waste water treatment plant sludge
- Transport phenomena in an agitated vessel with an eccentrically located impeller
- Membrane extraction of 1-phenylethanol from fermentation solution
- Theoretical study on transesterification in a combined process consisting of a reactive distillation column and a pervaporation unit
- Wall effects on terminal falling velocity of spherical particles moving in a Carreau model fluid
- The effect of the physical properties of the liquid phase on the gas-liquid mass transfer coefficient in two- and three-phase agitated systems
- Effectiveness of nitric oxide ozonation
- Modelling of nanocrystalline iron nitriding process — influence of specific surface area
- Effect of CeO2 and Sb2O3 on the phase transformation and optical properties of photostable titanium dioxide
- Carnauba wax microparticles produced by melt dispersion technique
- Complexation studies of 3-substituted β-diketones with selected d- and f-metal ions
- Influence of the solvent donor number on the O/W partition ratio of Cu(II) complexes of 1,2-dialkylimidazoles
- Continuous dialysis of sulphuric acid in the presence of zinc sulphate
- Differences in affinity of arylstilbazolium derivatives to tetraplex structures
- Fast ferritin immunoassay on PDMS microchips
