The effects of Soluble Gas Floatation Technology on the flow field of ladle and inclusion removal in RH refine process

Abstract

The effects of soluble gas flotation technology (SGFT) on the flow field of the ladle and the inclusion removal effect during RH refining process were studied by RH water model. The nucleation mechanisms and trajectories of the bubbles precipitated in RH water model and the prototype were also analyzed. The results show that when SGFT is used in RH water model, bubbles can be nucleated in the low pressure area near the blowholes; a large amount of fine bubbles moved into the ladle from the downleg, and bubbles which are smaller than 200 μm account for more than 80%; the precipitated bubbles will affect the flow field of RH water model resulting in increases of diffusion rate by 6.6%–11.6% and decreases of mixing time by 8–14s when the gas flow rates are 3–5 m3/h, respectively. However, bubbles can be nucleated in the upleg, downleg and vacuum chamber in prototype. The trajectories of bubbles in the RH water model and prototype are similar and the mechanisms of inclusion removal are similar. The removal rates of particles are 67.1%, 74.34% and 86.18% when the gas flow rates are 3, 4 and 5 m3/h, respectively.