Steel Flow into a Mold from a Submerged Nozzle with Eccentric Outputs

详细

The flow of steel melt into a mold has not been adequately studied. In general, analysis of the melt flow is a complex mathematical problem, and accordingly numerical modeling is employed. The present work employs Odinokov’s numerical method, which is based on a finite-difference form of the initial system of equations. This method has been successfully employed in continuum mechanics; in casting to determine the stress–strain state of shell-type molds; and in solving other technological problems. That suggests its universality. In the present work, it is applied to the hydrodynamic fluxes of liquid metal when steel is cast in a mold of rectangular cross section. The use of a submerged nozzle with eccentric holes for steel supply requires a three-dimensional mathematical model describing the metal fluxes into the mold. Odyssey software is used to simulate the processes in the mold. The calculation is based on the fundamental hydrodynamic equations and the proposed numerical model. The solution is obtained numerically and takes the form of a system of differential equations. The region of interest is divided into finite elements, and the system of equations is written in difference form for each element. The result obtained is the field of metal flow velocities into the mold. A numerical approach and a corresponding algorithm are developed for solution of the system of algebraic equations obtained and are incorporated in a computation program written in Fortran-4. By means of the mathematical model, the geometric dimensions of the mold and the cross section of the exit holes in the submerged nozzle may be varied. The model clarifies the pattern of metal flows, which affects the heat transfer by the mold walls, and permits determination of the optimal parameters of metal exit from the submerged nozzle in different casting conditions. As an example, the model is applied to steel casting in a mold of rectangular cross section (height 100 cm, horizontal dimensions 2000 × 40 cm). Steel flow from the submerged nozzle is eccentric in two directions within the horizontal plane. The results of solution are presented in graphic form. The pattern of metal fluxes into the mold is shown, and the magnitude and intensity of the fluxes is determined.