Modeling of thermogasodynamic parameters of neutral gas jets when spreading in converter cavity

The article considers the features and characteristics of spreading of neutral gas jets in the gas-dynamic section before interaction with the slag melt, which is further inflated to apply a refractory skull to the unit lining. The flow of a supersonic jet into the working space of the converter after tapping has the wave structure. The model for calculation of attached mass of the surrounding gas located in the converter working space is considered. The problem statement takes into account the known data on gas dynamics during the formation and flow of the jet, which affect the efficiency of turbulent transfer in the boundary layer. The calculation scheme is based on the hypothesis of existence of an initial boundary through which a chemically active gas from the environment penetrates into the gas jet, and the shape of the limit boundary is assumed to be cylindrical with a radius equal to the maximum radius of the first barrel of the non-calculated jet. Numerical calculations make it possible to determine the average mass velocity and temperature in an arbitrary section of a supersonic non-calculated jet before its introduction into the slag melt. The authors describe the influence of the relative temperature θ, nitrogen temperature in front of the nozzle T₀ during spreading of the jet in the converter cavity, and nitrogen flow through the nozzles V_н on value of the attached mass q, the averaged values of velocity and temperature W_x and T_x in an arbitrary cross-section x of a supersonic non-calculated jet in the gas dynamic section. The information obtained can be used in the development of gas-powder purging systems in aggregates and steel ladles, shotcrete systems and the supply of neutral gas jets when replacing oxygen flows during purging and using two-tier tuyeres.

1. Mokrinskii A.V., Lavrik A.N., Sokolov V.V., Protopopov E.V., Chernyatevich A.G. Prolongation of service life of lining of converter. Stal’. 2004, no. 5, pp. 40–44. (In Russ.).

2. Protopopov E.V., Galiullin T.R., Chernyatevich A.G., Sokolov V.V. Development of design of skull tuyeres and technology of gas-powder slagging of 350-ton converters of the West Siberian Metallurgical Combine. Ferrous Metallurgy. Bulletin of Scientific, Technical and Economic Information. 2009, no. 9, pp. 34–39. (In Russ.).

3. Nugumanov R.F., Protopopov E.V., Galiullin T.R., Chernyate­vich A.G., Chubina E.A. A new direction in improving the techno­logy of applying slag skull to the converter lining. Izvestiya. Ferrous Metallurgy. 2006, no. 12, pp. 7–12. (In Russ.).

4. Sian C., Wenyan Y., Conglie Z. Slag splashing for Bao Steel′s 300 metric ton BOF and crystallographic structure of its slag. Iron and Steelmaker. 2000, vol. 27, no. 7, pp. 39–41.

5. Lin L., Xiaoyan P., Fei G., Hewei D. Improvement and maintenance of MgO-C bottom-blowing tuyere in BOF converter for prolonging service life. In: Proceedings of the Unified Int. Tech. Conf. on Refractories. Chapter 124. UNITECR. 2013. P. 721–725. https://doi.org/10.1002/9781118837009.ch124

6. Sarkar S., Pal Т.К., Ghosh N.K., Garai S.K., Chintaiah P., Ku­jur M.K., Mishra A.N., Datta P.K. Enhancement of BOF producti­vity through modification of hot metal transfer ladle lining at Durgapur steel plant. SEAISI Quarterly (South East Asia Iron and Steel Institute). 2009, vol. 38, no. 1, pp. 39–42.

7. Zhaslan R.K., Zhautikov B.A., Romanov V.I., Aikeyeva A.A., Yerzhanov A.S. Improvement of methods for semi-finished carbon product tapping from the basic oxygen furnace (BOF). Metalurgija. 2022, vol. 61, no. 1, pp. 203–205.

8. Demidov K.N., Borisova T.V., Vozchikov A.P., etc. High-Magnesian Fluxes for Steelmaking. Moscow: Briquetted Materials Plant, 2013, 280 p. (In Russ.).

9. Barron M.A., Hilerio I. Numerical analysis of slag splashing in a steelmaking converter. Computer Technology and Application. 2011, vol. 2, no. 9, pp. 828–834.

10. Slovikovskii V.V., Gulyaeva A.V. Creation of high-efficiency promi­sing refractory materials and constructions for the lining of metallurgical units. Refractories and Industrial Ceramics. 2018, vol. 58, no. 5, pp. 475–480. https://doi.org/10.1007/s11148-018-0130-7

11. Cong I.G., Wei Y., Zhang Y., Peng F. Practice of dolomite slag replenishment technology on large face of converter. Naihuo Cailiao/Refractories. 2020, vol. 54, no. 3, pp. 243–245. https://doi.org/10.3969/j.issn.1001-1935.2020.03.014

12. Kumar D.S., Prasad G., Wishwanath S.C., Ghorui P.K., Mazumdar D., Ranjan M., Lal J.P.N. Converter life enhancement through optimization of operation practices. Ironmaking and Steelmaking. 2007, vol. 34, no. 6, pp. 521–528. https://doi.org/10.1179/174328107X203903

13. Balanin B.A., Zelenkov O.S., Kapustin E.A., Kuzemko R.D. Investigation of the attached mass of a supersonic jet at gas-dynamic section. In: Heat and Mass Transfer Processes in Baths of Steelmaking Units. Moscow: Metallurgiya, 1975, pp. 19–35. (In Russ.).

14. Kapustin E.A., Kuzemko R.D., Kuznetsov A.F., Sham P.I., Bol’shakov V.A. Possibilities of increasing the productivity of existing oxygen converters. Stal’. 1972, no. 2, pp. 112–115. (In Russ.).

15. Tiedje N.S. Solidification, processing and properties of ductile cast iron. Materials Science and Technology. 2010, vol. 26, no. 5, pp. 505–514. https://doi.org/10.1179/026708310X12668415533649

16. Chatterjee A. On some aspects of supersonic jets of interest in LD steelmaking. I. Jet design and characteristics. Iron and Steel. 1976, vol. 45, no. 69, pp. 627–634.

17. Tabata Y., Marsh R.S., Kelly P., etc. Improvement of BOP steel refining blowing control using wide angle lance nozzles. In: Steel Making Conference Proceedings. 1998, pp. 451–457.

18. Yavoiskii V.I., Dorofeev G.A., Povkh I.L. Theory of Purging a Steelmaking Bath. Moscow: Metallurgiya, 1974, 495 p. (In Russ.).

19. Protopopov E.V., Chernyatevich A.G. Investigation of interaction of oxygen jets with waste converter gases. Izvestiya. Ferrous Metallurgy. 1996, no. 10, pp. 5–9. (In Russ.).

20. Sizov A.M. Gas Dynamics and Heat Exchange of Gas Jets in Metallurgical Processes. Moscow: Metallurgiya, 1987, 256 p. (In Russ.).

21. Vurtsbakh R. Characteristics of free jets flowing out from blow nozz­les. Chernye metally. 1967, no. 10, pp. 12–20. (In Russ.).

22. Kapner J.D., Li K., Larson R.H. An experimental study of mixing phenomena of turbulent supersonic jets. International Journal of Heat and Mass Transfer. 1970, vol. 13, no. 5, pp. 932–937. https://doi.org/10.1016/0017-9310(70)90138-9

23. Sharma S.K., Hlinka J.W., Kern D.W. The bath circulation jet penet­ration and high – temperature reaction zone in BOF steelmaking. Steelmaking Proceedings. 1977, vol. 60, pp. 181–197.

24. Yavoiskii V.I., Yavoiskii A.V., Sizov A.M. The Use of Pulsating Blast in Steelmaking. Moscow: Metallurgiya, 1985, 176 p. (In Russ.).

25. Baptizmanskii V.I., Medzhibozhskii M.Ya., Okhotskii V.B. Conver­ter Processes in Steelmaking. Kiev-Donetsk: Vishcha shkola, 1984, 344 p. (In Russ.).