About the separation of finely divided particles during centrifugation in liquid media

Abstract

This work is devoted to the study of centrifugation processes, which are one of the most complex
processes of technology. The use of the action of the centrifugal force field for the separation
of heterogeneous liquid systems in a rotor system (centrifuge) is very effective. Separability of
centrifuged materials, multiphase dispersion, the relationship between phases cause ambiguous
processes of centrifugation, and therefore it is not always possible to accurately predict and evaluate
the main characteristics of the separation of heterogeneous systems in the centrifugal force field.
For a qualitative assessment of the main separation characteristics, such as the angular velocity
of rotation, the dependence of the angles of inclination of the glasses on the angular velocity, the
settling time of particles, etc., is created a mathematical model of the vertical rotor system. The
rotor represents a round disk on which cups (vial) with a multiphase liquid are symmetrically
suspended. A particular case of a fixed rotor is considered. Nonlinear differential equations of
motion of the suspension particle, which have no exact solution, are obtained. The research is
conducted by analytical and numerical methods. The dependence of the slope angles of the tubes
from the angular rotational speed of the rotor, sedimentation curves are obtained , which allow
estimating the time of particle deposition and the effect of the particle size distribution on the
separation process. The results of this research work allow us to determine with sufficient accuracy
all the necessary characteristics of the sedimentation working process, and also, in certain cases,
it is possible to exclude the conduct of experimental work. The results of the work confirm the
physical meaning of the process, which can serve as a justification for the use and introduction of
this mathematical model in industrial production.