A mathematical fluid flow model of gas injection in an argon–oxygen decarburisation (AOD) converter process has been coupled with a high temperature thermodynamic model. The current model is a further enhancement of an earlier developed three-dimensional, three-phase model, to also include some thermodynamics of the process. The model is based on fundamental transport equations and includes separate solutions for the steel, slag and the gas phases and their coupling by friction. The AOD model has been used to predict the first injection stage of decarburisation in an AOD converter. The predictions have been found to agree well with the corresponding results from an industrial process control model. One of the important observations from the simulations was that large concentration gradients of carbon exist in the AOD at an early stage and as the first injection step approaching its end the carbon gradients diminish. Also, the results show, in accordance with theory, that the local decarburisation rate is decreased at elevated pressures.
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References
1.
KrivskyWA: ‘The linde argon–oxygen process for stainless steel: a case study of major innovation in a basic industry’,Metall. Mater. Trans. B, 1973, 4B, (6), 1439–1447.
2.
AsaiSSzekelyJ: ‘Decarburization of stainless steel: Part I. A mathematical model for laboratory scale results’,Metall. Mater. Trans. B, 1974, 5B, (3), 651–657.
3.
SzekelyJAsaiS: ‘Decarburization of stainless steel: Part II. A mathematical model and a process optimization for industrial scale systems’,Metall. Trans., 1974, 5, (7), 1573–1580.
4.
FruehanRJ: ‘Reaction model for the AOD process’,Ironmaking Steelmaking, 1976, 3, (3), 153–158.
5.
WatanabeTTohgeT: ‘The study of the mechanism of decarburization for liquid stainless steel under reduced pressure’,Tetsu-to-Hagane, 1973, 59, (9), 1224–1236.
6.
Deb RoyTRobertsonDGC: ‘Mathematical model for stainless steelmaking – 1. Argon–oxygen and argon–oxygen–steam mixtures’,Ironmaking Steelmaking, 1978, 5, (5), 198–206.
7.
Deb RoyTRobertsonDGCLeachJCC: ‘Mathematical model for stainless steelmaking – 2. Application to aod heats’,Ironmaking Steelmaking, 1978, 5, (5), 207–210.
8.
OhnoTNishidaT: ‘Reaction model for the AOD process’,Tetsu-to-Hagane, 1977, 63, (13), 2094–2099.
9.
ReichelJSzekelyJ: ‘Mathematical models and experimental verification in the decarburization of industrial scale stainless steel melts’,Iron Steelmaker, 1995, 22B, (5), 41–48.
10.
WeiJ.-HZhuD.-P: ‘Mathematical modeling of the argon–oxygen decarburization refining process of stainless steel: Part I. Mathematical model of the process’,Metall. Mater. Trans. B, 2002, 33B, (1), 111–119.
11.
WeiJ.-HZhuD.-P: ‘Mathematical modeling of the argon–oxygen decarburization refining process of stainless steel: Part II. Application of the model to industrial practice’,Metall. Mater. Trans. B, 2002, 33B, (1), 121–127.
12.
ZhuHLWeiJHShiGMShuJHJiangQYChiHB: ‘Preliminary investigation of mathematical modeling of stainless steelmaking in an AOD converter: mathematical model of the process’,Steel Res. Int., 2007, 78, (4), 305–310.
13.
ShiGMWeiJHZhuHLShuJHJiangQYChiHB: ‘Preliminary investigation of mathematical modeling of stainless steelmaking in an AOD converter: application of the model and results’,Steel Res. Int., 2007, 78, (4), 311–317.
14.
WeiJ.-HCaoYZhuH.-LChiHB: ‘Mathematical modeling study on combined side and top blowing AOD refining process of stainless steel’,ISIJ Int., 2011, 51, (3), 365–374.
15.
JärvinenMKärnäAFabritiusT: ‘A detailed single bubble reaction sub-model for AOD process’,Steel Res. Int., 2009, 80, (6), 429–436.
16.
JonssonLSichenDJönssonP: ‘A new approach to model sulphur refining in a gas-stirred ladle. A coupled CFD and thermodynamic model’,ISIJ Int., 1998, 38, (3), 260–267.
17.
HallbergMJonssonLAlexisJ: ‘Modelling of hydrogen and sulphur refining during vacuum degassing in a ladle furnace’, Proc. Conf. SCANMET I, Luleå, Sweden, June 1999, MEFOS, 119–169.
18.
JonssonLJönssonPSeetharamanSSichenD: Proc. 6th Japan Nordic Countries Steel Symp., Nagoya, Japan, November 2000, Iron and Steel Institute of Japan.
19.
AnderssonMATJonssonLTIJönssonPG: ‘A thermodynamic and kinetic model of reoxidation and desulphurisation in the ladle furnace’,ISIJ Int., 2000, 40, (11), 1080–1088.
20.
AnderssonMATHallbergMJonssonLJönssonPG: ‘Slag–metal reactions during ladle treatment with focus on desulphurisation’,Ironnmaking Steelmaking, 2002, 29, (3), 224–232.
21.
AnderssonAMTJonssonLTIJönssonPG: ‘A model of reoxidation from the top slag and the effect on sulphur refining during vacuum degassing’,Scand. J. Metall., 2003, 32, (3), 123–136.
22.
HallbergMJonssonLTJonssonPGUndvallP: ‘Sulphur and hydrogen refining during vacuum degassing – a new concept for process control’,Stahl Eisen, 2005, 125, (5), 39–48.
23.
ErssonMHöglundLTillianderAJonssonLJönssonP: ‘Dynamic coupling of computational fluid dynamics and thermodynamics software: applied on a top blown converter’,ISIJ Int., 2008, 48, (2), 147–153.
24.
TillianderAJonssonLTIJönssonPG: ‘A three-dimensional three-phase model of gas injection in AOD converters’, Report 978-91-7501-266-7, KTH Royal Institute of Technology, Stockholm, Sweden, 2012.
25.
TernstedtPGyllenramRBengtssonJJönssonPG: ‘Using an AOD simulator workbench to support process control development’, Proc. 4th Int. Conf. on ‘Modelling and simulation of metallurgical processes in steelmaking’, Düsseldorf, Germany, June–July 2011, METEC.
26.
ChenYSKimSW: ‘Computation of turbulent flows using an extended k-epsilon turbulence closure model’, NASA CR-179204, NASA, Washington, DC, USA, 1987.
27.
SpaldingDB: ‘IPSA 1981: new developments and computed results’, CFDU Report HTS/81/2, Imperial College, London, UK, 1981.
28.
SpaldingDB:‘Numerical computation of multiphase fluid flow and heat-transfer’in‘Recent advances in numerical methods in fluids’(TaylorC.), Vol. 1, 139–168; 1980, Swansea, Pineridge Press.
