Characterization of the Mixing Flow Structure of Molten Steel in a Single Snorkel Vacuum Refining Furnace

Abstract

With the demand of high-quality steel and miniaturization of the special steel production, single snorkel vacuum refining process has been widely concerned in China recently, because of its simple structure and good performance of degassing and decarburization. In this study, a water model experimental system and a three-dimensional mathematical model based on two-fluid multiphase flow model have been built to analyze the refining efficiency limitation of the single snorkel vacuum refining furnace from the flow pattern and gas distribution. The results showed that there is a limited gas flow rate, and beyond this flow rate the gas column deviates to the wall and the redundant bubbles escape from the free surface, which will not further improve the refining efficiency and will lead to the erosion of the snorkel. In this case, the limited flow rate is 900 NL/h. Furthermore, the fluctuation of the free surface and the different structural parameters have significant effects on the flow field in single-snorkel vacuum refining furnace (SSF).

Industrial investigation of decarburization and desulphurization behaviour of 120 t new single snorkel degasser

“…Based on the above analysis, the NSSD could realize highefficiency desulphurization by the side-bottom combined blowing mode under symmetrical blowing on the immersion tube. The highest desulphurization degree of the NSSD has exceeded to that of the previous RH and SSRF [7,[13][14][15]. More importantly, a new desulphurization method in vacuum refining is proposed.…”

“…At present, RH is the main vacuum decarburization process used in industry, but RH powder spraying desulphurization faces the problems such as unstable desulphurization degree and serious erosion of refractories by desulphurizer (fluorite, etc.) [13][14][15].…”