Applied Biochemistry and Biotechnology

, 63:375

Measurement of the steady-state shear characteristics of filamentous suspensions using turbine, vane, and helical impellers

Authors

  • C. Kurt Svihla
    • Department of Chemical Engineering, Speed Scientific SchoolUniversity of Louisville
  • Sundeep N. Dronawat
    • Department of Chemical Engineering, Speed Scientific SchoolUniversity of Louisville
  • Jennifer A. Donnelly
    • Department of Chemical Engineering, Speed Scientific SchoolUniversity of Louisville
  • Thomas C. Rieth
    • Department of Chemical Engineering, Speed Scientific SchoolUniversity of Louisville
  • Thomas R. Hanley
    • Department of Chemical Engineering, Speed Scientific SchoolUniversity of Louisville
Session 3 Bioprocessing Research

DOI: 10.1007/BF02920439

Cite this article as:
Svihla, C.K., Dronawat, S.N., Donnelly, J.A. et al. Appl Biochem Biotechnol (1997) 63: 375. doi:10.1007/BF02920439

Abstract

The impeller viscometer technique is frequently used to characterize the rheology of filamentous suspensions in order to avoid difficulties encountered with conventional instruments. This work presents the results of experiments conducted with vane, turbine, and helical impellers. The validity of the assumptions made in the determination of the torque and shear-rate constants were assessed for each impeller type. For the turbine and vane impellers, an increase in the apparent torque constant c was observed with increasing Reynolds number even when measurements were confined to the viscous regime. The shear-rate constants determined for the vane and turbine impellers varied for different calibration fluids, which contradicts the assumptions usually invoked in the analysis of data for this technique. When the helical impeller was calibrated, consistent values for the torque and shear-rate constants were obtained. The three impeller types were also used to characterize the rheology of cellulose fiber suspensions and the results compared for consistency and reproducibility. The results have application in design of rheometers for use in process control and product quality assessment in the fermentation and pulp and paper industries.

Index Entries

Filamentous suspensionshelical impellersnon-Newtonian rheology

Copyright information

© Humana Press Inc. 1997