FORMATION OF AGGLOMERATE PARTICLES BY COAGULATION AND SINTERING .1. A 2-DIMENSIONAL SOLUTION OF THE POPULATION BALANCE EQUATION

A two-dimensional particle size distribution model is presented, for the first time, describing the evolution of both particle size and shape during gas phase powder production. In addition to the coagulation term, the governing population balance equation includes a coalescence contribution based on the particle sintering rate. It is the finite coalescence rate that results in the formation of irregularly shaped aggregate particles. Using volume and surface area as the two particle size dimensions, the aerosol dynamic equations are solved by extending a one-dimensional sectional technique to the two-dimensional space. This model leads to a quantitative characterization of powder morphology as well as the average size and polydispersity of the powders. The volume and surface area of the particles can also lead to an estimation of the surface fractal dimension of these particles from first principles.