The presented results of investigations are part of a larger study focused on the optimization of the flow and mixing of liquid steel in the industrial tundish of continuous casting machine. The numerical simulations were carried out concern the analysis of hydrodynamic conditions of liquid steel flow in a tundish operating in one of the national steelworks. Numerical simulations were performed using the commercial code ANSYS Fluent. The research concerns two different speeds of steel casting. In real conditions, these speeds are the most commonly used in the technological process when casting two different groups of steel. As a result of computational fluid dynamics (CFD) calculations, predicted spatial distributions of velocity and liquid steel turbulence fields and residence time distribution (RTD) curves were obtained. The volume fractions of different flows occurring in the tundish were also calculated. The results of the research allowed a detailed analysis of the influence of casting speed on the formation of hydrodynamic conditions prevailing in the reactor.
Detailed studies of the movement of liquid steel (hydrodynamics) on a real object are practically impossible. The solution to this problem are physical modelling carried out on water models and numerical modelling using appropriate programs. The method of numerical modelling thanks to the considerable computing power of modern computers gives the possibility of solving very complex problems. The paper presents the results of model tests of liquid flow through tundish. The examined object was model of the twonozzle tundish model. The ANSYS Fluent program was used to describe the behavior of liquid in the working area of the tundish model. Numerical simulations were carried out using two numerical methods of turbulence description: RANS (Reynolds-Averaged Navier-Stokes) – model k-ε and LES (Large Eddy Simulation). The results obtained from CFD calculations were compared with the results obtained using the water model.
The mathematical and numerical simulation model of the liquid steel flow in a tundish is presented in this paper. The problem was treated as a complex and solved by the finite element method. The single-strand slab tundish is used to continuous casting slabs. The internal work space of the tundish was modified by the following flow control devices. The first device was a striker pad situated in the pouring tundish zone. The second device was a baffle with three holes and the third device was a baffle without hole. The main purpose of using these devices was to cause a quiet liquid mixing as well as give directional metal flow upwards which facilitated inclusion floatation. The interaction of flow control devices on hydrodynamic conditions was received from numerical simulation. As a result of the computations carried out, the liquid steel flow and steel temperature fields were obtained. The influence of the tundish modification on velocity fields in the liquid phase of steel was estimated, because these have an essential influence on high quality of a continuous steel cast slab.
In this work, the authors proposed a modification of the working space one-strand tundish adapted for slab casting process. Numerical simulations of liquid steel flow in the considered flow reactor were performed. The tundish is equipped with a dam with a multi-hole filter. Two variants of the filter hole arrangement were tested and their effect on the liquid steel flow hydrodynamic structure in the tundish was examined. The computer calculations results were verified by performing experiments on the water model. The result of numerical and physical simulations an RTD (Residence Time Distribution) type F curve was generated, which define the transition zone between the cast steel grades during the sequential casting process. The results of the researches showed that the modification of a dam with a multi-hole filter affects on the formation of the liquid steel flow hydrodynamic structure and the transition zone. Furthermore, examinations of the liquid steel refining ability in the considered tundish were carried out. The influence of the filter holes arrangement on the non-metallic inclusions flotation process to the slag phase and liquid steel filtration processes was checked. Numerical simulations were performed in the Ansys-Fluent computer program.