The New Jersey Institute of Technology's
Electronic Theses & Dissertations Project

Title:	Power consumption in single-phase agitated vessels provided with multiple impellers
Author:	Chang, Gwo-Ming
View Online:	njit-etd1993-066 (xvi, 109 pages ~ 3.5 MB pdf)
Department:	Department of Civil and Environmental Engineering
Degree:	Master of Science
Program:	Environmental Engineering
Document Type:	Thesis
Advisory Committee:	Armenante, Piero M. (Committee chair) Perna, Angelo J. (Committee member) Cheremisinoff, Paul N. (Committee member)
Date:	1993-05
Keywords:	Impellers -- Energy consumption Mixing machinery
Availability:	Unrestricted
Abstract:	A significant amount of data can be found in the literature on power consumption of single-impeller agitation systems. However, little and incomplete information is available for power consumption in multiple-impeller systems. Therefore, the main objective of this study is to experimentally determine the power consumed by multiple impellers in mixing vessels as a function of impeller type, impeller off-bottom clearance, impeller spacing, and agitation speed. In this work, the power dissipated by combinations of one, two or three impellers of either identical types or different types was studied. The power drawn by each individual impeller was measured by means of strain gages. The results indicate that the power consumed by each impeller is strongly dependent on the combination of impeller types, spacing, clearance, and the presence of other impellers. For triple-disc turbine systems, the maximum power consumption was found when the intermediate impeller was spaced midway between the other two. In addition, the total power drawn was approximately equal to the sum of each individual power drawn when the spacing was about twice the impeller diameter.