xmlui.ArtifactBrowser.SimpleSearch.filter.source:Scientific papers of the University of Pardubice. Series A, Faculty of Chemical Technology. 24/2018
ISSN:1211-5541
Abstract:
The paper deals with the modeling of the constant-pressure cake filtration of suspensions
in viscoelastic liquids. The filtration equations are presented based on the capillary hybrid
model for power law fluid flow and comprising correction functions of the influence of
dispersing liquid elasticity. The validity of these equations has been verified experimentally.
The tests with suspensions of nearly spherical polystyrene particles Krasten in viscoelastic
aqueous solutions of polyacrylamides Kerafloc and Praestol were performed at constant
pressure in a laboratory cylindrical filtration unit. The rheological properties of liquids
have been measured on a rotational rheometer Mars II and an extensional rheometer
Caber 1. By analysing the experimental data, the filtration characteristics have been
evaluated. The elastic effects manifest themselves predominantly at the early period of the
filtration due to a higher filtration velocity which results in an evidently increased filtration
resistance. The satisfactory agreement of the experimental dependences of the cumulative
filtration volume on the time of filtration has been achieved when compared to those
obtained by the numerical solution of the proposed differential equation of filtration. This
confirms that the cake filtration from viscoelastic liquids can be predicted with a
satisfactory accuracy, thus making the suggested filtration model applicable in practice.