Behavior of Vertical Water Jet in a Cylindrical Mercury Bath

Abstract

Deionized water was injected through a single-hole nozzle at bottom center into a mercury bath in a cylindrical vessel. Water droplets were generated at the nozzle exit and they rose in the bath spreading in the radial direction. The holdup, frequency, mean rising velocity, and mean diameter of water droplets were measured with a two-contact electroresistivity probe and a laser void meter. The laser void meter can detect the arrival of water droplets and the rising velocity of them by analyzing the reflection of a laser beam at the interface between the two liquids. Both measured values of the water holdup α and water droplet frequency f_w followed the Gaussian distribution. Consequently, empirical correlations for α and f_w were derived in the momentum region near the nozzle exit and in the buoyancy region far from the nozzle exit by referring to those derived for bubbling jets in a cylindrical vessel. The mean rising velocity of water droplets u_w was calculated from the mass balance of rising water, and the mean diameter was calculated from the relation d_w=1.5α u_w/f_w. Empirical correlations for α, f_w, u_wand d_w were almost the same as their individual correlations for the bubble characteristics. Therefore there is no essential difference between a liquid-gas jet and a liquid-liquid jet.