Velocities of copper droplets in the De Laval atomization process

Atomization experiments were carried out at the Nanoval atomization unit. Particle image velocimetry (PIV) was used to determine the velocity vector fields of copper powder production via De Laval gas atomization. The experimental set-up designed to access the area closest to the atomization point was described in detail. Velocity vector fields were constructed by taking into account the distance from the nozzle exit. Instantaneous velocities on the atomization axis were calculated as a function of the atomization duration. Results from this study indicate a strong influence of the atomization pressures and the melt nozzle diameters on velocity characteristics. After processing, the droplet sizes were analyzed in relation to the working conditions using a Spraytec analyzer. A close relationship between velocity values and droplet sizes, depending on the operating parameters, was demonstrated.

Particle image velocimetry (PIV) was used to determine the velocity vector fields of copper powder production via De Laval gas atomization. Results from this study indicate a strong influence of the atomization pressures and the melt nozzle diameters on velocity characteristics. A close relationship between velocity values and droplet sizes, depending on the operating parameters, was demonstrated.Figure optionsDownload as PowerPoint slideHighlights
► We design a specific optical set-up to provide PIV measures on Cu droplets in the vicinity of the De Laval nozzle.
► We examine changes in the velocity profiles and intensities with the operating parameters.
► Increasing atomization pressure will increase the droplet velocity and decrease the droplet size.
► Increasing the melt nozzle diameter will induce the decrease in droplet velocity and the increase in droplet size.