EXPERIMENTAL-DETERMINATION OF THE PERMEABILITY AND RELATIVE VISCOSITY FOR FINE LATEXES AND YEAST SUSPENSIONS

The specific cake resistances of thin layers of fine latexes and of yeast cells have been determined from flux data for pressure drops of up to 100 kPa in a static filtration device. A single correlation has been developed that relates the cake resistance to particle diameter for monodisperse rigid latex spheres with diameteis between 1.0 and 6.7 pm. The specific resistance of the yeast cell layers was found to be almost 50 times larger than that of the rigid latex spheres of the same median diameter. The relative viscosities of a 7.3 pm latex and yeast cell suspensions have been measured in a cone-and-plate viscometer. Empirical correlations relating the relative viscosity to the solids volume fraction were developed from linear regression of the data for each suspension. A correlation was also developed that relates the relative viscosity of the yeast cell suspension to the cell count. The effective shear-viscosities were not observed to exhibit a significant shear-rate dependence. However, an apparent viscosity increase with time was observed. This is attributed to radial migration of the Darticles as a result of interactions with the surface of the cone. © 1990, Taylor & Francis Group, LLC. All rights reserved.