Numerical study on the evaporation process of feedstock powder under transient states in pulse-modulated induction thermal plasmas for nanoparticle synthesis

Abstract

Abstract A numerical model was developed on the evaporation process of intermittently fed feedstock into pulse-modulated induction thermal plasma (PMITP). This experimental method combining the PMITP with intermittent feedstock feeding has been developed for the synthesis of large amounts of nanoparticles. To treat this method, a full transient numerical model for the PMITP was combined with transient equations of particle behaviour with different time steps. Transient two-way interactions from particle evaporation to the PMITP were also taken into account at each time step as source terms in mass, momentum and energy conservations. The temperature, gas flow field and mass fraction of feedstock vapor were obtained in the transient state in the PMITP with the motion of feedstock particles. The calculation results were compared with the experimental results for the Ar I line and feedstock atomic line. They were found to be in fair agreement even in the transient state.