ABSTRACT
The physicochemical mechanics of the basic processes of chemical technology studies the general laws of the transfer of a substance based on the traditional concepts of continuum mechanics. This chapter considers stochastic equations that are an analog of the mass-transfer equations and determine the nature of the distribution of particles in a dispersed medium, taking into account the course of various physical processes. The Fokker–Planck equation describes disperse systems with a continuous change in the size of dispersed particles and properties of the medium. Although the processes of coalescence and fragmentation are characterized by an abrupt change in the properties of particles, in principle, for a sufficiently large time interval, the change in the mean properties can be assumed to be quasi-continuous with an infinitesimal jump. The chapter considers the problems of mass transfer associated with the presence of polydisperse particles and droplets, accompanied by coalescence, crushing, and agglomeration.
