BEHAVIOR OF VERTICAL WATER-JET IN A CYLIN DRICAL MERCURY BATH

Deionized water was injected through a single-hole nozzle at bottom ce nter into a mercury bath in a cylindrical vessel. Water droplets were generated at the nozzle exit and they rose in the bath spreading in th e radial direction. The holdup, frequency, mean rising velocity, and m ean diameter of water droplets were measured with a two-contact electr oresistivity probe and a laser void meter. The laser void meter can de tect 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 alpha and water droplet frequency f(w) followed the Gaussian distribution. Consequentl y, empirical correlations for alpha and f(w) were derived in the momen tum region near the nozzle exit and in the buoyancy region far from th e nozzle exit by referring to those derived for bubbling jets in a cyl indrical vessel. The mean rising velocity of water droplets u(w)BAR wa s calculated from the mass balance of rising water, and the mean diame ter was calculated from the relation d(w)BAR = 1.5alpha u(w)BAR/f(w). Empirical correlations for alpha, f(w), u(w)BAR and d(w)BAR were almos t the same as their individual correlations for the bubble characteris tics. Therefore there is no essential difference between a liquid-gas jet and a liquid-liquid jet.