Field synergy between the molten steel flow field and the temperature distribution was analyzed at first in this paper. It shows when the synergy angle between the molten steel flow field and the ...temperature gradient field is more than 90° in the tundish, the molten steel temperature distribution is more homogeneous and the synergy number is smaller. Then the flow fields and temperature distributions in the one-strand tundish established with different flow controls were numerically calculated. The results show that the synergy angles are more than 90° in the back-flow zones and gradually decrease as far from the back-flow zones till to almost 0°. The temperature gradient are large in the zones near the tundish wall boundary and around the stopper. When the tundish equipped with a turbulence inhibitor, a weir and a dam, the synergy angles are more than 90° in the majority of molten steel flow domains, the temperature distribution is even. So, the established controls in the tundish can modify the flow characteristics and temperature distribution.
The article presents the results of liquid steel flow and mixing in tundish when applying different equipment to modernize the tundish working zone. The six-strand continuous casting tundish of a ...trough-type was studied. Such tundish is an object with geometry adjusted to the conditions of particular CC machine, which is installed in one of a polish steel plant. The problems suggested in research were solved basing on physical model experiment.
The article presents the results of industrial measurements carried out on continuous casting machine during its normal working operation. The aim of the research was to determine the influence of ...steel preheating level on the size of particular crystallization areas of ingot primary structure.
The aim of presented studies was to investigate the fluid flow change and non-metallic inclusions removal changes due to tundish construction modifications. In presented study, numerical simulations ...were used. Numerical simulations are carried out with the finite-volume commercial code ANSYS Fluent. Steady-state casting conditions for the flow structure and the inclusions removal process are analysed.
Hydrodynamic conditions occurring in the tundish are strictly connected with the equipment of its working zone. On such conditions influence also many factors such as: the amount of steel present in ...the working zone, the velocity of steel casting. In order to study these relationships the CFD simulation and physical modelling were applied. Research was carried out for the following parameters: different velocity of steel casting, bare tundish and tundish with turbulence inhibitor (kind of working zone equipment) and the amount of liquid steel in tundish equal 5,5 Mg and 7,5 Mg.
Molten steel flow and inclusion removal behavior in tundish were studied by using numerical simulation and water-model experiment. The effects of tundish characteristics such as width, depth, length ...on inclusion outflow ratio were evaluated and a new inclusion outflow model was deduced using tundish Width/Depth ratio. The results are as follows: (1) By a bottom short-circuit flow in a tundish, inclusion outflow ratio is extremely increased in the case of Width/Depth ratio<0.6. (2) With the enlargement of tundish width in same volume, inclusion outflow ratio is decreased. (3) When Width/Depth ratio exceeds 1.5, cross-sectional circular flow is enlarged and inclusion outflow ratio attains to a constant value.
Hitherto existing investigations concerning the ceramic filter use in the steel making processes have given good results. The obtained results of filtration have proved that this method may be used ...as an effective and cheap way of steel filtration from non-metallic inclusions. Placing filters in the tundish is the best location considering the limitation of the possibility of secondary pollution of steel. Yet, the results presented in this paper, of an experiment prepared and carried out in the industrial environment, are the only positive results obtained, which are connected with so much quantities of liquid steel processed with use of the multi-hole ceramic filters.
Steel flow and heat transfer in tundishes under non-isothermal and non-adiabatic conditions are physically and mathematically modeled. For this purpose thermal step inputs in both types of models are ...applied and temperature measurements as well as computations of flow and heat transfer at unsteady state are carried out. Experimental measurements of output responses to thermal step inputs fed in the tundish model and the transient solution of the three dimensional Navier-Stoke's equations keep a very good agreement. Isothermal lines of water model and those belonging to the prototype under non-adabatic conditions are not equivalent for the same thermal step input and this promotes different velocity fields of water in the model and liquied steel in the prototype. As velocity fields have a direct influence on inclusions removal from steel to the covering tundish slag it is recommended to have caution on the employment of non-isothermal water models to interpret the actual behavior of steel flow and inclusions dynamics in industrial tundishes.
In the Japanese steelmaking industry, continuous casting technologies for manufacturing defect-free slab or bloom with high productivity are becoming increasingly important. The surface and internal ...defects of steel products attributable to steelmaking conditions originate in the entrapment of inclusions or gas bubbles by the solidifying shell in the casting mold or strand, and in the formation of center-line segregation at the final stage of solidification. To suppress such defects and ensure high quality in continuous casting process, many advanced technologies have been developed and applied in industrial plants as follows: (1) To promote the removal of inclusion from molten steel in the tundish, centrifugal flow tundish (CF-tundish) or H-shaped tundish was developed. (2) To prevent the entrainment of inclusion or gas bubbles into molten steel in the mold, flow control devices using the electromagnetic brake and electromagnetic stirrer have been adopted. Flow control mold is one example which is characterized by two static magnetic fields imposed on the entire width of a slab. Surface and internal defects in cast slabs are remarkably reduced by this newly designed tool. (3) To reduce the degree of center-line segregation, the solft-reduction process with a plane reduction unit or short-pitched roll segment for cast slab and continuous forging process with an anvil for cast bloom were applied to practical operations.
The effect of weir, dam, slotted dam and their combinations on the molten steel flow dynamics in a tundish was investigated in a physical model by studying the flow pattern and residence time ...distribution. The number, position and size of the above flow modifiers, Froude number, tundish width and inlet-exit distance were varied during the course of the study. For all tundish widths, weirs of all sizes were found to produce short circuiting in the tundish fluid flow system. Whereas use of a dam alone or in combination with a weir or a slotted dam eliminates short circuited flow completely. The residence time and variance are found to be influenced by the tundish width, inlet-exit distance and FM configurations. Empirical correlations were obtained to calculate residence time and variance.
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