Modelling of gas-dynamic processes in the design of small-sized installation for the production of micro-powders by gas spraying melt quenching in a horizontal reactor.

Abstract

A new scheme for obtaining metal powders by gas spraying is present. The atomization takes place in a horizontal reactor where the interacting flows of the melt and the atomizing gas are perpendicular. The theoretical calculations performed within the selected approximation, quantitative values of process parameters, describing the interaction of flows were obtained as a result. The penetration depth of the gas stream into the melt jet at different pressures and gas flow rates was appreciated. The liquid melt jet, in initial approximation, as a flow of non-reactive particles of a spherical shape with a diameter in the range 40-250 μm in order to evaluate the selected parameters of the design of the spray chamber (atomizer) was considered. A relationship between the distribution of gas flow velocities and the distribution of the velocities of condensed particles in the atomizer chamber was modelled. We have found the areas of the atomizer in which the “reverse” flow of light particles (with a diameter of less than 80 μm). The vortex motion of the gas in the chamber induces this effect. We have found and modeled the correlation between the distribution of gas flow velocities and the distribution of the velocities of condensed particles in the atomizer chamber. The simulation results show that the investigated range of gas-dynamic characteristics in the sprayer of the chosen design ensures the production of powder materials of a given dispersion.