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.
Similar content being viewed by others
References
Svihla, C. K., Dronawat, S. N., and Hanley, T. R. (1995),Appl. Biochem. Biotechnol. 51/52, 355–366.
Allen, D. G. and Robinson, C. W. (1990),Chem. Engng. Sci. 45(1), 37–48.
Chisti, M. Y. and Moo-Young, M. (1988),Biotechnol. Bioeng. 31, 487–494.
Donnelly, J. (1995), M. Eng. Thesis, University of Louisville, Louisville, Kentucky.
Kemblowski, Z., Sek, J., and Budzynski, P. (1988),Rheological Acta 27, 82–91.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Svihla, C.K., Dronawat, S.N., Donnelly, J.A. et al. Measurement of the steady-state shear characteristics of filamentous suspensions using turbine, vane, and helical impellers. Appl Biochem Biotechnol 63, 375–385 (1997). https://doi.org/10.1007/BF02920439
Issue Date:
DOI: https://doi.org/10.1007/BF02920439