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Title: Advanced impeller geometry boosts liquid agitation

Journal Article · · Chemical Engineering (New York); (United States)
OSTI ID:7021293
; ;  [1]
  1. Univ. of Arkansas, Fayetteville, AR (United States)

A traditional agitator impeller often functions as a rather inefficient pump because of the way it produces fluid motion and pressure head. However, one can improve the amount of flow or shear generated by an impeller at constant power consumption and torque by changing its design. For example, a high-efficiency, axial-flow impeller produces more fluid motion per unit of power at constant torque than an otherwise similar pitched-blade turbine. The more-vigorous fluid motion cuts blend time and enhances heat-transfer in various flow-controlled mixing operations, such as blending of miscible fluids. For most applications, a higher degree of agitation intensity can be achieved on the same machine by substituting a high-efficiency impeller for a conventional pitched-blade unit. The high-efficiency impeller features a larger geometric pitch angle (30--60 deg) at the hub than at the tip (10--30 deg). Results from recently conducted controlled experiments indicate the beneficial effects of the high-efficiency impeller on blend time and heat-transfer coefficients in liquid-liquid mixing as well as solids suspension. This articles focuses on liquid agitation, with discussions of solids suspension set aside for a forthcoming piece in this series of articles on mixing.

OSTI ID:
7021293
Journal Information:
Chemical Engineering (New York); (United States), Vol. 101:8; ISSN 0009-2460
Country of Publication:
United States
Language:
English