Effect of Swirling-Flow Gas Injection Angle on Multiphase Flow and Mixing Behavior in RH Refining Process

doi:10.12068/j.issn.1005-3026.2025.20230312

Abstract

Abstract:

The effects of swirling-flow gas injection angles on multiphase flow， circulation flow and mixing time in the RH refining process were investigated using numerical simulation. Compared with the conventional gas injection mode， the circulation flow increased by 17.8% and 20.1%， respectively， when the swirling-flow gas injection nozzles with 30° horizontal angle + 15° vertical angle and 30° horizontal angle + 30° vertical angle were employed. Moreover， the mixing time was reduced by 32.6% and 21.4%， respectively. With the swirling-flow gas injection technology， a swirling steel flow was generated in the up-snorkel and the steel flow velocity was more uniform. The swirling-flow caused argon bubbles to move centripetally in the up-snorkel. The bubble dispersion was improved compared to the conventional gas injection mode. This promoted the gas-liquid two-phase interaction， mass transfer and mixing efficiency. Additionally， the wall shear stress was reduced from 500 Pa to around 100 Pa when the swirling-flow gas injection of 30° horizontal angle 15°vertical angle was applied， compared to swirling-flow gas injection with only 30° horizontal angle. Also， the area of the high wall shear stress region was decreased greatly， which is helpful to reduce the erosion of refractory materials by molten steel.

Key words: RH refining, swirling-flow gas injection, circulation flow, mixing time, numerical simulation

CLC Number:

TF 769.4

Yu-chao HAN, Qing-hua XIE, Pei-yuan NI, Ying LI. Effect of Swirling-Flow Gas Injection Angle on Multiphase Flow and Mixing Behavior in RH Refining Process[J]. Journal of Northeastern University(Natural Science), 2025, 46(4): 16-23.

Figures/Tables 11

Fig.1 Geometry of the RH furnace and distribution of the up-snorkel nozzles

Fig.2 Comparison of tracer concentration variations between numerical model prediction and water model measurement

Fig.3 Effect of different nozzle angles on circulation flow rate

Fig.4 Mixing time distribution evaluated by the volume monitoring method under different gas injection conditions

Fig.5 Steel flow streamline under different injection modes

Fig.6 Velocity distribution on the vertical middle plane of RH furnace under different injection modes

Fig.7 Velocity conditions on cross-section of the up-snorkel at location of H=900 mm under different injection conditions

Fig.8 Shear stress on the wall of up-snorkel under different injection modes

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