Jet characteristics of a double-structure oxygen lance and its interaction with the molten pool in BOF steelmaking

Abstract The jet performance of an oxygen lance nozzle influences the smelting rhythm, smelting index, and energy consumption of a converter. Due to the complexity of the process of converter smelting, the changing temperature and gas composition in the converter significantly impact the jet characteristics of the oxygen lance nozzle in the smelting process; however, research on the change law of jet characteristics in different smelting periods is limited. In this study, we used Ansys Fluent 17.0, which is commercially available fluid simulation software, to simulate the variation of jet characteristics of a mixed injection comprising 6% CO2 and 94% O2; the mixed injection was tested using a dual-parameter oxygen lance nozzle in the early, middle, and late stages of smelting. The results show that the increase of CO concentration and ambient temperature in the converter lead to a decrease in the attenuation rate of jet velocity, improved independence of multiple jets, and an increase in the impact area of jets on the molten pool. Thus, when designing and employing oxygen lance nozzles, the influence of ambient temperature and furnace gas composition on jet characteristics must be considered.

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Research and Application of New Oxygen Lance for BOF Steelmaking

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.335-336.74 ◽

2011 ◽

Vol 335-336 ◽

pp. 74-79 ◽

Cited By ~ 1

Author(s):

Jiang Ping Rao ◽

Guang Qiang Li ◽

Zhi Zheng Yang

Keyword(s):

Operation Mode ◽

Supersonic Jet ◽

The Other ◽

Smelting Process ◽

Oxygen Lance ◽

Oxygen Equilibrium ◽

Other Hand ◽

Equilibrium Control ◽

Jet Characteristics

This paper compares the structure and basic points of the new lance with traditional ones, analyses the new design with center hole in head in fields of theoretical supersonic jet characteristics including penetrating depth and stirring energy, operation mode in smelting process and. The application results show its advantages in keeping whole dephosphorizing rate, final carbon-oxygen equilibrium control of steel and cost reducing, on the other hand, point to its several drawbacks. Optimize solutions are introduced at the end.

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Effects of Nozzle Layout and Parameters on the Jet Characteristics of a CO2 + O2 Mixed Oxygen Lance

Metallurgical and Materials Transactions B ◽

10.1007/s11663-020-02048-8 ◽

2021 ◽

Author(s):

Chao Feng ◽

Rong Zhu ◽

Kai Dong ◽

Guangsheng Wei ◽

Baochen Han ◽

...

Keyword(s):

Oxygen Lance ◽

Jet Characteristics

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Turbulence Calculations of a Dual-Structure Oxygen Lance for Converter Based on Hydrodynamics

Mathematical Problems in Engineering ◽

10.1155/2021/5785889 ◽

2021 ◽

Vol 2021 ◽

pp. 1-16

Author(s):

Hongbin Jia ◽

Yanxin Li ◽

Peng Han ◽

Kun Liu ◽

Haolei Han ◽

...

Keyword(s):

Flow Rate ◽

Molten Pool ◽

Rate Ratio ◽

Flow Characteristics ◽

Radial Pressure ◽

Flow Rate Ratio ◽

Oxygen Lance ◽

Special Equipment ◽

Dual Structure ◽

Jet Behavior

The oxygen lance is a piece of special equipment in the converter steelmaking process for blowing oxygen into the molten steel. After more than 80 years of development, the structure and function of the oxygen lance have undergone many changes. In this paper, based on the theory of hydrodynamics, the jet behavior characteristics of a dual-structure oxygen lance for the converter are determined and optimized by CFD simulations and compared with those of the traditional-structure oxygen lance. The research results show that multiple jets deflect to the central axis of the oxygen lance during movement and the inclination angle of the nozzle holes influences the jet deflection. A decrease in the nozzle hole angle results in an increase in the mutual suction between the streams. With the increasing flow rate through the large holes in the new dual-structure oxygen lance, the dynamic radial pressure increases at the middle of the jet. The jet flow characteristics of the new dual-structure oxygen lance are better than those of the traditional oxygen lance. Its impact on the molten pool includes greater momentum, a larger impact area, and a more uniform and powerful stirring of the molten pool. A nozzle angle of 14° combined with a flow rate ratio of 65% and a nozzle angle of 17° combined with a flow rate ratio of 35% are the optimal parameters for the new dual-structure oxygen lance.

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