Modélisation CFD de la formation de nanoparticules dans un réacteur de synthèse à plasma

The present work reports on the simulation of metal powder formation in a Inductively Coupled Plasma reactor. A carrier gas transports the metal powder into the reactor in where it attains the vapor phase. The products are recovered after a quenching process. The model accounts for particle formation by nucleation and growth by condensation and brownian coagulation. Transport of particles occurs by convection, thermophoresis, and brownian diffusion. Axial and radial diffusion of particles are considered. The commercially computational fluid dynamics code FLUENT Ã 6.0, is used for the detailed calculation of the turbulent fluid flow and particle growth. This code is then completed with a model for aerosol dynamics using the first three moments of the particle size distribution. The simulation is applied for the production of ultrafine iron powders. The fields of the macroscopic properties of the aerosol population and the contribution of the different mechanisms are analyzed under various conditions. The effect of different operating parameters on the properties of the powder generated is studied."--Résumé abrégé par UMI