Mixing Technology of Stratified Density Layer by Gas-Liquid Two-Phase Jet

This paper experimentally treats the mixing of a two-layer density-stratified fluid generated by gas-liquid two-phase jet in a cubic tank. The purpose of this study is to clarify the mixing optimum by gas-liquid two-phase jet for destruction of density stratification. The upper and lower fluids were water and salt water, respectively, with the lower fluid issued vertically upward from a circular nozzle put at the center of the bottom in the tank. We conducted the mixing experiment, the experimental parameters were the total superficial velocity and the volumetric flow ratio of the jet. The total superficial velocity and the volumetric flow ratio of the jet range from 1.5 to 6.0 m/s and from 0 to 1.0, respectively. The mixing behaviors of density stratification were visualized and the density variation during the mixing was measured in situ. Based on the visualized and measured results, an evaluation method for the mixing time was developed. We discussed the relation between the experimental parameters and the mixing time. Then, it was clarified that different behaviors between liquid jet and gas-liquid two-phase jet were observed and the effect of the volumetric flow ratio of the jet on the mixing time was varied in each the total superficial velocity of the jet.