For the sodium-water reaction accident, it is important to grasp the structure of gas jets submerged in liquid sodium and associated droplet sizes. In this study, we successfully obtained visualized images of inert gas jets injected into liquid sodium. Formation processes of liquid sodium droplets entrained into the gas jets and drop-size distributions are discussed.
Visualization was conducted on upward argon gas jets impinging to a glass tube in stationary liquid sodium pool. The gas jet behavior was observed by using a bore scope inserted inside of the glass tube. The gas jet velocities at the nozzle exit were 13 < u0 < 125 m/s.
For u0 > 50 m/s, liquid droplets began to be formed. The formation processes of liquid droplets were classified into (1) spray type; a liquid film formed on the nozzle is blown and atomized by the gas jets and (2) entrainment type; attributed to the instability of a gas cavity-liquid phase interface. But the difference in the drop-size distribution of the both formation processes was not significant. Mean droplet diameter of liquid sodium was confirmed to be agreed well with an empirical equation suggested from a model experiment using water.