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2011 | 32 | 4 | 311-319
Article title

A study on blending characteristics of axial flow impellers

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EN
Abstracts
EN
This paper presents an analysis of the blending characteristics of axial flow high-speed impellers under a turbulent regime of flow of an agitated low viscosity liquid. The conductivity method is used to determine the time course of blending (homogenisation) of miscible liquids in a pilot plant fully baffled mixing vessel, and a torquemeter is used for measuring the impeller power input in the same system. Four-blade and six-blade pitched blade impellers and three high efficiency axial flow impellers are tested for the given degree of homogeneity (98%).The experimental results and also the results of the authors' previous study, in accordance with the theoretical approach described in the literature, show that there is a universal relationship between the impeller power number and the dimensionless blending time, taking into consideration the impeller-to-vessel diameter ratio, independent of the geometry of the axial flow impeller but dependent on the degree of homogeneity. This relationship is found to be valid on a pilot plant scale under a turbulent flow regime of an agitated liquid.
Publisher

Year
Volume
32
Issue
4
Pages
311-319
Physical description
Dates
published
1 - 12 - 2011
online
15 - 2 - 2012
Contributors
author
  • Faculty of Mechanical Engineering, Department of Process Engineering, Czech Technical University in Prague, Technická 4, 166 07 Prague 6, Czech Republic
  • Faculty of Mechanical Engineering, Department of Process Engineering, Czech Technical University in Prague, Technická 4, 166 07 Prague 6, Czech Republic
References
  • Fořt I., 1989. Flow and turbulence in vessels with axial impellers, In: Uhl V.W., Gray J.B. (Eds.), Mixing, theory and practice, Vol. III. Academic Press, New York, 133-197.
  • Fořt I., Jirout T., Rieger F., Allner R., Sperling R., 2001. Study of the blending efficiency of pitched blade impellers. Acta Polytechnica, 41, 7-13.
  • Grenville R. K., Nienow A. W., 2003. Blending in miscible liquid, In: Paul E. L., Otiemo-Obeng V. A., Kresta S. M. (Eds.), Industrial mixing. Science and practice. Wiley Interscience, New York, 507-542.
  • Khang S. J., Levenspiel O., 1976. New scale-up and design criteria for stirrer agitated batch mixing vessels. Chem Eng. Sci., 31, 569-577. DOI: 10.1016/0009-2509(76)80020-6.[Crossref]
  • Kramers H., Baars G. M., Knoll W. H., 1953. A comparative study on the rate of mixing in stirred tanks. Chem. Eng. Sci., 2, 35-42. DOI: 10.1016/0009-2509(53)80006-0.[Crossref]
  • Liu M., 2011a. Prediction of tracer concentration and mixing in CFSTR with mean age distribution. Ind. Eng. Chem. Res., 50, 5838-5851. DOI: 10.1021/ie2002395.[Crossref][WoS]
  • Liu M., 2011b. Quantitative characterisation of mixing in stirred tank reactors with mean age distribution. Can. Jour. Chem. Eng., 89, 1018-1028. DOI: 10.0122/cjce.20563.[Crossref][WoS]
  • Mavros P., Xuereb C., Fořt I., Bertrand J., 2002. Investigation by laser Doppler velocimetry of the effects of liquid flow rates and feed positions on the flow patterns induced in a stirred tank by an axial - flow impeller. Chem. Eng. Sci., 57, 3939-3952. DOI: 10.1016/0009-2509(02)00268-3.[Crossref]
  • Nienow A. W., 1997. On impeller circulation and mixing effectiveness in the turbulent regime. Chem. Eng. Sci., 52, 2557-2565. DOI: 10.1016/0009-2509(97)00072-9.[Crossref]
  • Procházka J., Landau J., 1961. Homogenization of miscible liquids by rotary impellers. Collect. Czech. Chem. Commun., 26, 2961-2974.
  • Seichter P., Pešl L., 2005. Design of rotary impellers - science or art? CHEMagazin, 15(2), 8-11 (in Czech).
Document Type
Publication order reference
Identifiers
YADDA identifier
bwmeta1.element.-psjd-doi-10_2478_v10176-011-0025-3
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