Study on Multiphase Flow Characteristics During RH Refining Process Affected by Nonradial Arrangement of Gas-Blowing Nozzle

Bath stirring, degassing, and decarburization in steel refining are strongly related to flow behaviors. The bubble plume produced in Ruhrstahl-Heraeus (RH) up-snorkel plays an important role during refining, since it not only acts as a bubble pump, but also provides the reaction interface. Herein, it is aimed to form a new flow pattern in the up-snorkel by using a nonradially arranged gas-injection nozzle to enhance the 260 ton RH refining process. The results show that an upward spiral steel flow is produced, when nonradial gas-injection nozzles are used in the up-snorkel. Meanwhile, some bubbles moved toward the center region of the up-snorkel, which may be caused by the centripetal effect in a rotational steel flow. This leads to a more uniform bubble distribution on the cross section of the snorkel, compared to that of the conventional case. Specifically, the circulation flow rate is increased by about 18.0%, and the mixing time are shortened by about 26.2% (criteria of & PLUSMN;5%), compared to that of the conventional case. In addition, the inclusion removal rate is increased by 0.5%, 4.8%, and 11.3% for the inclusion size of 20, 50, and 100 & mu;m, respectively, compared to the conventional radial nozzle case.

Automated summary

By using nonradial gas-injection nozzles in the up-snorkel, an upward spiral steel flow is produced, which improves the 260 ton RH refining process. Compared to the conventional case, this improvement increases the circulation flow rate by about 18.0%, shortens the mixing time by about 26.2%, and enhances the inclusion removal rate for different inclusion sizes.