Flow induced by an impeller in an unbaffled tank—I. Experimental
Flow induced by an impeller in an unbaffled cylindrical tank was studied. In Part I, both mean and turbulent (root-mean-square) velocities in all three directions were measured using a laser Doppler anemometer (LDA). The effects of the impeller rotational speed and clearance of tank bottom on flow c...
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Published in | Chemical engineering science Vol. 49; no. 4; pp. 549 - 560 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Oxford
Elsevier Ltd
1994
Elsevier |
Subjects | |
Online Access | Get full text |
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Summary: | Flow induced by an impeller in an unbaffled cylindrical tank was studied. In Part I, both mean and turbulent (root-mean-square) velocities in all three directions were measured using a laser Doppler anemometer (LDA). The effects of the impeller rotational speed and clearance of tank bottom on flow characteristics were investigated. It is found that the flow turbulence is approximately homogeneous in the bulk liquid except in the impeller stream. Near the gas—liquid interface the turbulence is strongly damped by the surface tension, and is fairly anisotropic. The mean and rms velocities in dimensionless form were observed to be independent of the impeller rotational speed. It was also found that the impeller clearance to the tank bottom affects the pumping capacity of the impeller, i.e. the rate, of flow ejected by the impeller blades, but does not influence the circulation capacity of flow in a vertical plane. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0009-2509 1873-4405 |
DOI: | 10.1016/0009-2509(94)80055-3 |