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

• Tipo: Artigo em Revista Científica Internacional
• Data: 1997

Autores

F. T. Pinho (Autor) FEUP; Francisco Piqueiro (Autor) FEUP; Proenca, MF (Autor) Outra; Santos, AM (Autor) Outra

Revista

Título: Canadian Journal of Chemical Engineering

Vol. 75

Páginas: 832-842

ISSN: 0008-4034

Editora: Wiley-Blackwell

Indexação

ISI Web of Knowledge - 8 Citações

Scopus - 11 Citações

Outras Informações

ID Authenticus: 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.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 11