Power and mean flow characteristics in mixing vessels agitated by hyperboloid stirrers

• Type: Article in International Scientific Journal
• Date: 1997

Authors

F. T. Pinho (Author) FEUP; Francisco Piqueiro (Author) FEUP; Proenca, MF (Author) Other; Santos, AM (Author) Other

Journal

Title: Canadian Journal of Chemical Engineering

Vol. 75

Pages: 832-842

ISSN: 0008-4034

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 8 Citations

ISI Web of Science

Scopus - 11 Citations

Scientific classification

FOS: Engineering and technology > Other engineering and technologies

CORDIS: Physical sciences > Physics > Classical mechanics > Fluid dynamics

Other information

Authenticus ID: P-001-AHA

Abstract (EN): The mean flow and energy consumption in vessels powered by hyperboloid stirrers was investigated. The Newton number followed an inverse Linear law for Reynolds numbers below approximately 200, which had values more than twice higher the corresponding Neu ton number for a standard Rushton turbine. At high Reynolds number flows the Power number varied between 0.5 for a D/T = 0.78 impeller to 0.95 for a D/T = 0.24 impeller, as compared to a value of 5 for the standard Rushton stirrer, and to values of 0.31 and 1.58 for the Chemineer and Prochem hydrofoils. The power consumption did not change with the fluid height and was double for the double-stack configuration. The shear ribs below the impeller were the main contributor to the increased energy loss relative to a non-shear ribbed impeller and the small clearance had no major effect upon the power consumption. For the D/T = 1/3 hyperboloid stirrer the flow in the whole tank was rather gentle, defining a circulation number of 0.57, thus leading to a circulation efficiency more than 7 times lower than that of the hydrofoils.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11