Influence of Nozzle Position and Nozzle Radian Angle on the Perfect Mixing Time during Bottom Blowing with Two Nozzles Using a Water Model

Mi Ran Na; Sun-Joong Kim

doi:10.7844/kirr.2025.34.2.43

All Issue

2025 Vol.34, Issue 2 Preview Page Next Page

Research Paper

Influence of Nozzle Position and Nozzle Radian Angle on the Perfect Mixing Time during Bottom Blowing with Two Nozzles Using a Water Model 수모델 활용 저취 시 이중 노즐의 위치 및 중심각에 의한 균일 혼합 시간의 변화

30 April 2025. pp. 43-52

PDF XML

Abstract

In the steelmaking process, the stirring by bottom blowing is one of important technologies for homogenizing the temperature and chemical composition of molten steel and removing inclusions, and can improve the refining speed of the process. In general, the stirring energy from bottom blowing is governed by the gas flow rate, the shape parameter of furnace, and the position of nozzle. And the stirring energy affects the perfect mixing time. In this study, we conducted fundamental research to optimize the dual nozzle positions required for multi-nozzle design, based on the nozzle pattern and shape of an industrial furnace process. Using the water model, the influence of the radial position and radian angle of the dual nozzle on the perfect mixing time was investigated by measuring the electrical conductivity. The radial position of dual nozzle varied from 0.15 to 0.70, positioning from the center to a position close to the wall, and the radian angle varied from 30° to 90°. The perfect mixing time obtained from the water model was subjected to regression analysis to derive a relationship between the nozzle radial position, the radian angle, the weight of water, and the gas flow rate. In addition, this study summarizes the optimization conditions and the relationship between stirring energy and perfect mixing time from previously reported water model experiments using dual nozzles.

Keywords

Bottom blowing

perfect mixing time

dual nozzle

nozzle position

water model

제강 공정 중 저취 교반은 용강의 온도 및 화학적 조성 균질화, 개재물을 제거하는 중요한 공정 기술이며, 공정의 정련 속도를 개선할 수 있다. 저취 교반에 의한 교반 에너지는 일반적으로 가스 취입량, 로의 형상, 노즐의 설치 위치 등의 영향을 받는다. 그리고 교반 에너지는 속도론적 개념에 있어서 균일 혼합시간을 결정짓는 중요한 요소이다. 본 연구에서는 실제 전로 공정의 노즐 패턴 및 형상에 기반하여 다중 노즐 설계에 있어서 필요한 2중 노즐 위치의 최적화에 대한 기초 연구를 진행하였다. 수모델을 활용하여 2중 노즐의 반경 위치 및 중심각의 영향에 따른 균일 혼합시간의 변화를 전기전도로 측정을 통해 조사하였다. 노즐 반경 위치는 0.15 ~ 0.70로 중심부에서 로벽에 가까운 위치로 변화하였으며, 중심각의 변화는 30° ~ 90°로 변화하였다. 수모델 실험으로 얻어진 균일혼합시간을 회귀분석하여 노즐의 반경 위치 및 중심각, 물의 용량, 가스 유량 등과의 관계식을 도출하였다. 또한, 기존에 보고된 2중 노즐을 사용한 수모델 실험의 최적화 조건, 균일혼합시간과 교반에너지의 관계식을 본 연구에서 정리하였다.

키워드

저취교반

균일 혼합 시간

이중 노즐

노즐 위치

수모델

References

A.N. Conejo and S.Y. Kitamura, 2010 : Fluid flow phenomena in bottom gas-stirred ladles with top layer-Part I. Fluid flow, Doctoral dissertation, Tohoku University.

S. Joo and R.I.L. Guthrie, 1992 : Modeling flows and mixing in steelmaking ladles designed for single-and dual-plug bubbling operations, Metall. Trans. B, 23(6), pp.765-778.

10.1007/BF02656455

M.Y. Zhu, T. Inomoto, I. Sawada, et al., 1995 : Fluid flow and mixing phenomena in the ladle stirred by argon through multi-tuyere, ISIJ Int., 35(5), pp.472-479.

10.2355/isijinternational.35.472

A. Jauhiainen, L. Jonsson and D.Y. Sheng, 2001 : Modelling of alloy mixing into steel-The influence of porous plug placement in the ladle bottom on the mixing of alloys into steel in a gas‐stirred ladle. A comparison made by numerical simulation, Scand. J. Metall, 30(4), pp.242-253.

10.1034/j.1600-0692.2001.300408.x

H.Y. Tang, J.S. Li, C.H. Xie, et al., 2009 : Rational argon stirring for a 150-t ladle furnace, Int. J. Miner. Metall. Mater., 16(4), pp.383-386.

10.1016/S1674-4799(09)60068-6

D.Q. Geng, H. Lei and J.C. He, 2010 : Optimization of mixing time in a ladle with dual plugs, Int. J. Miner. Metall. Mater., 17(6), pp.709-714.

10.1007/s12613-010-0378-5

A.N. Conejo, S. Kitamura, N. Maruoka, 2013 : Effects of top layer, nozzle arrangement, and gas flow rate on mixing time in agitated ladles by bottom gas injection, Metall. Mater. Trans. B, 44, pp.914-923.

10.1007/s11663-013-9829-5

A.M.A. Villeda, M.A.R. Argaez, A.N. Conejo, 2014 : Effect of slag properties on mixing phenomena in gas-stirred ladles by physical modeling, ISIJ Int., 54(1), pp.1-8.

10.2355/isijinternational.54.1

R. González-Bernal, G. Solorio-Diaz and A. Ramos-Banderas, et al., 2018 : Effect of the fluid-dynamic structure on the mixing time of a ladle furnace, Steel Res. Int., 89(2), 1700281.

10.1002/srin.201700281

A.S. Gómez, A.N. Conejo and R. Zenit 2018 : Effect of separation angle and nozzle radial position on mixing time in ladles with two nozzles, J. Appl. Fluid Mech., 11(1), pp.11-20.

10.29252/jafm.11.01.27503

M. Chen, N. Wang, Y. Yao, et al., 2007 : Optimal mixing effect of LF Bottom‐Blown stirring by two nozzles, Steel Res. Int., 78(6), pp.468-472.

10.1002/srin.200706233

D. Mazumdar, P. Dhandapani and R. Sarvanakumar, 2017 : Modeling and optimisation of gas stirred ladle systems, ISIJ Int., 57(2), pp.286-295.

10.2355/isijinternational.ISIJINT-2015-701

M. Sano and K. Mori, 1983 : Fluid flow and mixing characteristics in a gas-stirred molten metal bath, Trans. Iron Steel Inst. Jpn., 23(2), pp.169-175.

10.2355/isijinternational1966.23.169

O. Hadia, T. Emi, S. Yamada, F. Sudo, 1980 : Injection of Lime-Base Powder Mixtures to Desulfurize Hot Metal in Torpedo Cars, Proc. 2nd Int. Conf. Injection Metallurgy (SCANINJECT II), MEFOS & Jernkontoret, pp.20, MEFOS, Printed in Lulea

Q. Ying, L. Yun and L. Liu, 1983 : A Model Study of Mixing and Mass Transfer in Ladle Injection, Proc. 3rd Int. Conf. Refining of Iron Steel by Powder Injection (SCANINJECT III), pp.21, MEFOS, Printed in Lulea.

D. Mazumdar and R.I.L Guthrie, 1986 : Mixing models for gas stirred metallurgical reactors, Metall. Trans. B, 17, pp.725-733.

10.1007/BF02657134

M. Ramirez-Argaez, 2007 : Numerical simulation of fluid flow and mixing in gas-stirred ladles, Mater. Manuf. Process., 23(1), pp.59-68.

10.1080/10426910701524568

Information

Publisher :The Korean Institute of Resources Recycling
Publisher(Ko) :한국자원리싸이클링학회
Journal Title :Resources Recycling
Journal Title(Ko) :자원리싸이클링
Volume : 34
No :2
Pages :43-52
Received Date : 2025-02-24
Revised Date : 2025-03-26; 2025-04-16
Accepted Date : 2025-04-18
DOI :https://doi.org/10.7844/kirr.2025.34.2.43

Resources Recycling ISSN:2765-3439(Print) 2765-3447(Online) 자원리싸이클링

All Issue