Numerical Analysis of the Influence of the Modification of the Ladle Shroud on Fluid Flow Behavior in a One-strand Tundish during Continuous Steel Casting

A tundish is a device from which liquid steel is pour into a mold. Therefore tundish hydrodynamic conditions have a significant impact on solidification during continuous steel casting (CSC) process. Modification of ladle shroud workspace, allows for the modification of liquid steel movement in the tundish. In the following work, numerical simulations were performed which allowed the impact of the modification of the ladle shroud workspace on the liquid steel flow structure in a one-strand tundish to be determined. In order to assess the impact of the modification of the ladle shroud on the behavior of the liquid steel in the tundish, simulations were performed, on the basis of which the percentage share of stagnant, ideal mixing and plug flow zones were determined. In addition, the mixing parameters were determined, allowing the estimation of casting duration during sequential casting. The flow fields of liquid steel for each modification of the ladle shroud were performed. The average velocity of liquid steel flowing through the tundish, the Reynolds number and turbulent intensity were also described. The obtained results showed, among others, that the application of three cylinders with a diameter of 0.041 m into the ladle shroud with a diameter of 0.11 m increases the share of active flow in the tundish in relation to the tundish with Conventional Ladle Shroud. At the same time, applying a ladle shroud with a diameter of 0.11 m during casting is the most favorable in relation to the hydrodynamics of the tundish.

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CURRENT PROBLEMS AND PERSPECTIVES OF COMPUTER SIMULATION OF CONTINUOUS STEEL CASTING

Izvestiya Ferrous Metallurgy ◽

10.17073/0368-0797-2019-5-374-380 ◽

2019 ◽

Vol 62 (5) ◽

pp. 374-380

Author(s):

A. A. Shipel’nikov ◽

A. N. Rogotovskii ◽

N. A. Bobyleva ◽

S. V. Skakov

Keyword(s):

Liquid Steel ◽

Steel Casting ◽

Computer Experiments ◽

Continuous Steel Casting ◽

Continuous Steel ◽

Effective Control ◽

Melt Flow ◽

Submerged Nozzle ◽

Deterministic Dynamic ◽

Steel Flow

Nowadays we can see increase in using of engineering analysis systems in the field of continuous steel casting simulation due to their high accuracy and convergence with industrial experiments results. Such powerful systems as «ANSYS» and «ProCast» allows solving gas-, hydrodynamic and thermal problems, the parallel interaction of which constitutes the essence of most metallurgical processes. Group of authors from the LSTU Chair “Metallurgical technology” have successfully carried out computer experiments in tundish and continuous casting mold processes simulation. The experiments were aimed at first, on studying of further improving in liquid steel flow modifiers (partitions, turbo-stops, thresholds) design, at second, on influence of argon blowing regime on liquid steel flow parameters in the 50-ton tundish workspace, and, at third, on influence of submerged nozzles design on the liquid steel flow in crystallizer, assuming deterministic-dynamic operation mode. The results of calculations are velocity fields of liquid steel flow and flow temperatures fields in tundish and crystallizer, as well as temperature fields in the tundish refractory lining. An equation of primary flow average velocity change on exit from submerged nozzle was also formulated. These preliminary results allow us to assess the velocity changes and direction of the melt flow and formation of volumes with different melt temperatures when using flow modifiers in the ladle, including using of “argon curtain” in the casting chamber. Obtained data on melt flow motion and on location of erosion spots in crystallizing «crust», also on the presence of temperature gradient zones in various regions of crystallizer workspace may be useful to practice engineers engaged in choice of crystallizer submerged nozzle design. Effective control of melt flow in tundish and in crystallizer allows significant improvements in continuous cast slabs and rolled products quality in context of reducing metal products rejection due to defects associated with slag or nonmetallic inclusions presence and due to cracks formed as the result of insufficient thickness of crystallized «crust».

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Physical Modeling of Mold Slag Entrainment in Continuous Steel Casting Mold with Consideration the Impact of Mold Powder Layer

steel research international ◽

10.1002/srin.201800110 ◽

2018 ◽

Vol 89 (9) ◽

pp. 1800110 ◽

Cited By ~ 6

Author(s):

Marcin Bielnicki ◽

Jan Jowsa

Keyword(s):

Physical Modeling ◽

Steel Casting ◽

Continuous Steel Casting ◽

Continuous Steel ◽

Powder Layer ◽

Mold Powder ◽

Casting Mold ◽

Mold Slag ◽

Slag Entrainment ◽

The Impact

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Comparison of Optimization-Regulation Algorithms for Secondary Cooling in Continuous Steel Casting

Metals ◽

10.3390/met11020237 ◽

2021 ◽

Vol 11 (2) ◽

pp. 237

Author(s):

Michal Brezina ◽

Tomas Mauder ◽

Lubomir Klimes ◽

Josef Stetina

Keyword(s):

Convergence Rate ◽

Water Flow ◽

Steel Casting ◽

Casting Process ◽

Continuous Steel Casting ◽

Continuous Steel ◽

Cooling Zone ◽

Secondary Cooling ◽

Flow Rates ◽

Secondary Cooling Zone

The paper presents the comparison of optimization-regulation algorithms applied to the secondary cooling zone in continuous steel casting where the semi-product withdraws most of its thermal energy. In steel production, requirements towards obtaining defect-free semi-products are increasing day-by-day and the products, which would satisfy requirements of the consumers a few decades ago, are now far below the minimum required quality. To fulfill the quality demands towards minimum occurrence of defects in secondary cooling as possible, some regulation in the casting process is needed. The main concept of this paper is to analyze and compare the most known metaheuristic optimization approaches applied to the continuous steel casting process. Heat transfer and solidification phenomena are solved by using a fast 2.5D slice numerical model. The objective function is set to minimize the surface temperature differences in secondary cooling zones between calculated and targeted surface temperatures by suitable water flow rates through cooling nozzles. Obtained optimization results are discussed and the most suitable algorithm for this type of optimization problem is identified. Temperature deviations and cooling water flow rates in the secondary cooling zone, together with convergence rate and operation times needed to reach the stop criterium for each optimization approach, are analyzed and compared to target casting conditions based on a required temperature distribution of the strand. The paper also contains a brief description of applied heuristic algorithms. Some of the algorithms exhibited faster convergence rate than others, but the optimal solution was reached in every optimization run by only one algorithm.

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