Particle production by gas-to-particle conversion in turbulent flows

The goal of this paper is to present an analysis of the interplay of chemical reaction, Brownian and shear induced aerosol coagulation, during gas phase production of solid powders. For this purpose, a simple model for the dynamic behavior of these particles is developed by approximating the particle size distribution by a lognormal function throughout the process. Using this model, the key dimensionless groups determining the size characteristics, average diameter and polydispersity, of the product powder are identified. At the early stages of powder production chemical reaction and Brownian coagulation are the controlling phenomena while later on turbulent coagulation dominates. It is found, for the first time, that there is an optimal particle diameter with respect to the polydispersity of the product powder.