Particle suspension in the turbulent regime: the effect of impeller type and impeller/vessel configuration

Particle suspension in water has been studied using Rushton turbines, pitched blade turbines (pumping upwards and downwards), Chemineer HE3 and Lightnin A310 hydrofoils pumping downwards, and Ekato Intermig agitators. Flat and profiled bottoms have been used. The dimensionless parameter S, which is...

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Main Authors: Ibrahim, S., Nienow, A.W.
Format: Article
Published: 1996
Subjects:
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author Ibrahim, S.
Nienow, A.W.
author_facet Ibrahim, S.
Nienow, A.W.
author_sort Ibrahim, S.
collection UM
description Particle suspension in water has been studied using Rushton turbines, pitched blade turbines (pumping upwards and downwards), Chemineer HE3 and Lightnin A310 hydrofoils pumping downwards, and Ekato Intermig agitators. Flat and profiled bottoms have been used. The dimensionless parameter S, which is related to the minimum impeller speed for complete solids suspension based on the work of Zwietering, has been used to generalize the results for two different particles. The configuration requiring the lowest specific energy dissipation rate in the flat-bottomed tank was a downward- pumping impeller of 0.35 to 0.4 times the vessel diameter with a clearance off the base of 1/4 the vessel height. Under these conditions, the main flow pattern was such that the piles of solids associated with the regions of flow reversal at the periphery and of the centre of the base were both removed at about the same speed. By modifying the base to fill in these zones where solids collect, the minimum specific energy dissipation rate associated with this configuration using the HE3 hydrofoils could be further reduced by a factor of about 4 to 5. Compared to the HE3 hydrofoils, the Rushton turbines and the Intermigs required minimum specific energy dissipation rates for suspension 5 to 10 times higher at equivalent clearances and vessel base configurations.
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spelling um.eprints-94342017-07-03T06:40:12Z http://eprints.um.edu.my/9434/ Particle suspension in the turbulent regime: the effect of impeller type and impeller/vessel configuration Ibrahim, S. Nienow, A.W. T Technology (General) TA Engineering (General). Civil engineering (General) Particle suspension in water has been studied using Rushton turbines, pitched blade turbines (pumping upwards and downwards), Chemineer HE3 and Lightnin A310 hydrofoils pumping downwards, and Ekato Intermig agitators. Flat and profiled bottoms have been used. The dimensionless parameter S, which is related to the minimum impeller speed for complete solids suspension based on the work of Zwietering, has been used to generalize the results for two different particles. The configuration requiring the lowest specific energy dissipation rate in the flat-bottomed tank was a downward- pumping impeller of 0.35 to 0.4 times the vessel diameter with a clearance off the base of 1/4 the vessel height. Under these conditions, the main flow pattern was such that the piles of solids associated with the regions of flow reversal at the periphery and of the centre of the base were both removed at about the same speed. By modifying the base to fill in these zones where solids collect, the minimum specific energy dissipation rate associated with this configuration using the HE3 hydrofoils could be further reduced by a factor of about 4 to 5. Compared to the HE3 hydrofoils, the Rushton turbines and the Intermigs required minimum specific energy dissipation rates for suspension 5 to 10 times higher at equivalent clearances and vessel base configurations. 1996 Article PeerReviewed Ibrahim, S. and Nienow, A.W. (1996) Particle suspension in the turbulent regime: the effect of impeller type and impeller/vessel configuration. Chemical Engineering Research & Design, 74 (A6). pp. 679-688. ISSN 0263-8762, http://www.scopus.com/inward/record.url?eid=2-s2.0-0030239355&partnerID=40&md5=852a3a12dfe369e4a6a12b7c07af0b97 http://www.cheric.org/research/tech/periodicals/view.php?seq=51784
spellingShingle T Technology (General)
TA Engineering (General). Civil engineering (General)
Ibrahim, S.
Nienow, A.W.
Particle suspension in the turbulent regime: the effect of impeller type and impeller/vessel configuration
title Particle suspension in the turbulent regime: the effect of impeller type and impeller/vessel configuration
title_full Particle suspension in the turbulent regime: the effect of impeller type and impeller/vessel configuration
title_fullStr Particle suspension in the turbulent regime: the effect of impeller type and impeller/vessel configuration
title_full_unstemmed Particle suspension in the turbulent regime: the effect of impeller type and impeller/vessel configuration
title_short Particle suspension in the turbulent regime: the effect of impeller type and impeller/vessel configuration
title_sort particle suspension in the turbulent regime the effect of impeller type and impeller vessel configuration
topic T Technology (General)
TA Engineering (General). Civil engineering (General)
work_keys_str_mv AT ibrahims particlesuspensionintheturbulentregimetheeffectofimpellertypeandimpellervesselconfiguration
AT nienowaw particlesuspensionintheturbulentregimetheeffectofimpellertypeandimpellervesselconfiguration