Kinetics of Reversible Gravitational Coagulation in a Spatially Uniform Disperse System

Spatially uniform disperse system where the processes of coagulation, fragmentation, and sedimentation of fractal aggregates occur simultaneously, was discussed. Kinetics of the passage of such system from the initial state, where the dispersed phase was already separated into fine and coarse fractions, to a new equilibrium state was studied. The enlargement of aggregates takes place both due to the capture of the particles of fine fraction and their adherence during collisions. Disintegration of aggregates occurs by the detachment of fragments from the aggregate surface under the action of hydrodynamic stresses arising during aggregate sedimentation. The solution of the coagulation–fragmentation equations indicates that, at the intermediate stage of a process, the aggregate mass distribution density is characterized by polymodal structure, which is degenerated into bimodal by the end of the passage.