Design and numerical simulation of a novel vortex structure for copper slag melting reduction process

Abstract

A new type of vortex entrainment feeder structure has been established to address the problem of powder suspension and the inability to be quickly sucked up by the melt pool in the current mechanical stirring melting reduction tank. Numerical simulations of the particle motion behaviour and fluid flow characteristics of the four feeders have been carried out to determine the justification of the structural design. An experimentally verified numerical approach was established using the Eulerian model coupled with the Dense Discrete Phase Model (DDPM). The results show that the Type-4 (Double-flow channel) creates vortexes with significant effect, the shape of the entrainment vortex is uniform, and the velocity is high, the radial and axial particle concentration is 1.75 times and 1.44 times higher than that of the Type-1 (No-flow channel), and the particles are dispersed optimally, with a more extended residence mixing time. The mass flow variance of the particles was reduced by 55 % compared to the Type-1, the number of high-velocity particles was > 92 %, and the eccentricity distance of the positional distribution was shortened. The main driving forces for radial and axial particle dispersion are negative pressure entrainment of the gas phase and axial velocity difference. The variance values of the swirling number in the cylinder/cone zone were reduced by 91.3 % and 38.5 %, respectively, and the stability of the swirl flow field was improved.