A model for ultrafine powder production in a plasma reactor

A model is proposed for the analysis of the production of ultrafine particles in thermal plasma reactors. The model initially solves the fluid flow, temperature, and concentration fields using a classical control volume approach. The nucleation and growth of ultrafine particles are then solved along each streamline. The evolution of the particle distribution is described by a statistical apprach, using the first moments of the distribution as the dependent variables. Brownian coalescence is considered in the free molecular regime. In the discussion, the model is used to demonstrate the effects of some important parameters, such as the initial concentration of metal (Fe) vapor, its radial distribution, and the radial injection of a cooling gas, on the particle size distribution. 15 ref.--AA