Introduction
Raise of demands to quality of released metal products and aspiration to increase productivity of existing steel-making units and technical-and-economic indexes of steel-smelting manufacture at the expense of a removal of a part of production operations in a steel teeming ladle were, as it is known, principal causes of development of extraoven machining of the steel which has gained the name "secondary" or "ladle" metallurgy. Within last decades in connection with a wide heading of continuous casting of the steel demanding maintenance of a constancy of temperature and a chemical compound of metal, and increase in volumes of output of a steel with the low maintenance of impurity extraoven machining was extended practically at all metallurgical factories both in Ukraine, and in industrially developed countries.
Work Urgency.
Working out of the progressive production engineering providing improvement of quality and increase of volumes of released metal products, and also decrease in specific consumption of materials, is the priority direction of development of steel-smelting manufacture in modern conditions. Level of attained parametres of martempering of office properties of smelted metal in many respects depends on the processing methods which are carried out at the final stages of process of reception of a steel to which extraoven machining refers to.
Necessity of perfection of production engineering of extraoven machining of a steel demands realisation extensive theoretical and the experimental researches directed on working out of physical and mathematical models of studied processes, providing their successful practical application. Therefore working out of theoretical and technological bases of extraoven machining of a steel is now an actual problem.
The Work Purpose.
Working out, perfection and a heading of production engineering of extraoven machining of a steel for the purpose of improvement of quality of metal products and raise of technical-and-economic indexes of manufacture of metal.
The Primary Goals:
1. Working out of theoretical both technological bases and research of the processes proceeding at extraoven machining of a steel.
2. Research of the mechanism of machining of a steel by gas-ascending streams at a bath barbotage neutral gases.
3. Working out of physical models for an estimation of hydrodynamics of the bath, allowing to define optimum duration of mixing of melt for its averaging on a chemical compound and temperature at metal blow by inert gases.
4. Working out of the equipment for physical modelling of the processes, allowing to size up the hydrodynamic processes proceeding in a metal bath at a purge by inert gases.
5. A heading of results theoretical and experimental researches in practice of manufacture and extraoven machining of a steel.
The Basic Results:
Purge became the inert gas, favourably different from other ways of extraoven machining by rather low expenses, allows to solve successfully such problems, as decrease in inhomogeneity of metal on temperature and a chemical compound, martempering of conditions of removal from it non-metallics inclusion, and also partial decontamination of melt. Thus, successful application of progressive production engineering of improvement of quality of a smelted steel demands comprehensive studying of features of the physical processes proceeding both in the most liquid metal, and in a layer of gas or air medium bounding on it. For reception of the quantitative information on process of processes of mixing of metal in a scoop at gas inflation methods of physical and mathematical modelling have been used. For acceleration of processes spent in a scoop melt homogenization is important. It is considered that for fuller use of energy of gas bubblering melt the lance diving depth should be maximum. A method of physical modelling sized up agency of intensity of supply of gas and a lance diving depth on duration of homogenization in steel a scoop.
Conclusions:
Thus, on the basis of the executed observations of character of traffic of streams in the overhead part of a scoop the basic hydrodynamic streams can be classified conditionally on 5 integrated subdomains with equal conditions (a direction of vectors of speeds, a rate of speed, intensity of turbulence) area ascending газожидкостного a stream penetrating through a butter layer (slag); area of an exit of blown in gas in an aerosphere, switching on разбрызгивание slag and metal (that is area of a stain of a gas make on a scoop surface); area of discending currents of metal which slide along a slag layer from top to down; area of horizontal streams of metal (with a quantity of vials of gas) which are propelled along a slag surface in a direction from an upflow to scoop periphery; area of formation of a mix of metal, slag and vials of blown in gas which is formed under a slag layer in a zone of traffic of upflows. Development and sizes of this or that of the gated out subdomains depend on a row of factors, from which the expense of blown in gas, quantity продувных knots and their arrangement, and also viscosity of the slag, what miscellaneous at different stages of extraoven machining is main.
The List of the Literature:
1. Mixing Time and Correlation for Ladles Stirred with Dual Porous Plugs J.Mandal, S.Patil, M.Madan, D.Mazumdar// Metallurgical and Materials Transaction B, Vol.36 B, August, 2005
2. Modeling criteria for flow simulation in gas stirred ladles: experimental study D.Mazumdar, H.B.Kim, R.I.L.Guthrie// Ironmaking and Steelmaking. 2000. Vol.27. No4. P.302-308
3. Modeling of Slag Eye Formation over a Metal Bath Due to Gas Bubbling KRISHNAKUMAR KRISHNAPISHARODY and GORDON A. IRONS// METALLURGICAL AND MATERIALS TRANSACTIONS B VOLUME 37B, OCTOBER 2006-763
4. Fluid Flow and Mixing through Multi-Tuyere Phenomena the Ladle Stirred by Argon Miao-YongZHU.TakeoINOMOTО. Ikuo SAWADA and Tse-Chiang HSIAO// ISIJ International. Vol. 35 (1995). No. 5, pp. 472-479
5. Transient Fluid Flow Phenomena in a Gas Stirred Liquid Bath with Top Oil Layer-Approach by Numerical Simulation and Water Model Experiments Jeong Whan HAN, Seung Hwan HEO1, Dong Heun KAM1, Byung Don YOU, Jong Jin PAK and Hyo Suk SONG// ISIJ International, Vol. 41 (2001), No. 10, pp. 1165-1173
6. Correlation for Area of Spout Eyes in Ladle Metallurgy (Comments on "Spout Eye Area Correlation in Ladle Metallurgy" by Subagyo, Brooks and Irons) Kimitoshi YONEZAWA and Klaus SCHWERDTFEGER// ISIJ International, Vol. 44 (2004), No. 1, pp. 217-219
7. Transient Flow and Mixing in Steelmaking Ladles during the Initial Period of Gas Stirring Dipak MAZUMDAR, Rishey YADAV and Binod B. MAHATO// ISIJ International, Vol. 42 (2002), No. 1, pp. 106-108
8. Generation of Droplets in Slag-Metal Emulsions through Top Gas Blowing SUBAGYO, G. A. BROOKS, K. S. COLEY and G. A. IRONS// ISIJ International, Vol. 43 (2003), No. 7, pp. 983-989
9. Смирнов А.Н., Сафонов В.М., Дорохова Л.В., Цупрун А.Ю. - Металлургические мини-заводы - 2005
