Print this page Selecting A Centrifugal Pump To Handle A Viscous Liquid
Randall W. Whitesides, P.E.
Course Outline
The practice of Chemical, Civil, Environmental, and Mechanical Engineering can routinely involve centrifugal pumping applications. This course is intended for those Engineers who may be called upon to select or size a centrifugal pump that must handle, transport, or otherwise pump a non-water fluid whose viscosity is significantly greater than that of water. The course assumes the student has previous general knowledge of hydraulics and centrifugal pump terminology.
This course provides a relatively simple, concise overview and review of centrifugal pump characteristics as they relate to viscous fluid applications. It does not delve into highly theoretical, rigorous mathematics to accomplish this end. The course material can be used as a reference source for future real world situations.
Students of this
two-hour online course will be provided with a basic understanding of fluid
viscosity and its effects on the performance and efficiency of centrifugal pumps.
The course presents definitions, effects and recommendations for conveying viscous
fluids. It presents established predictive techniques to estimate viscous pump
performance.
This course includes a multiple choice quiz at the end.
Learning Objective
At
the conclusion of this course, the student will:
-
Understand the effects of viscous fluids on centrifugal pump operation, and
-
Learn the method to estimate these effects and thereby select the correct
pump for the viscous fluid application.
Course Content
Course Summary
Viscosity is a measure of a fluid's resistance to flow. Pumped liquids are generally considered viscous when their absolute viscosity exceeds 40 centipoise. This is the point at which the effect on pump performance becomes appreciable; at 100 centipoise the effect is pronounced.
A centrifugal pump handling a viscous liquid must develop a greater capacity and head, and it requires a larger power input than the same pump handling water. When the required viscous performance of a pump is known, it is possible to select a pump with a greater pseudo water performance that will in turn produce the required actual viscous performance. This selection process is accomplished through the Hydraulic Institute's performance correction charts which must be used with caution. The charts should not be used for mixed-flow or axial flow pumps or pumps of special design. Use of the charts should be limited to pumps handling uniform liquids; slurries, gels, paper stock and other binary mixtures will cause incorrect pump selections.
In essence, the viscosity correction factors obtained from the Hydraulic Institute Standards enable the Engineer to derive the viscous performance curve of a pump from its standard water performance curves.
Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.
DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDHonline.com or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered professional engineer. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.
