Effects of tundish size, tundish design and casting flow rate on fluid flow phenomena of liquid steel

Fluid dynamics of liquid steel in continuous casting tundishes is closely r elated to tundish volume and geometry, existence of Row control devices and steel flow rate. To study this complex interaction physical and mathematic al models were used in the present work. The first one was based in a 1/3 s cale water model with injection of tracers and the second one on-the soluti on to the steady state-turbulent Navier-Stokes equations using the kappa-ep silon [1] approximation for the turbulent viscosity. When the tundish size is increased from 30 t to 50 t the tracer indicates a strong bypassing in the second case. The mathematical predictions indicate very high fluid velocities along the tundish bottom in agreement with the experimental findings. The employment of turbulence inhibitors promotes a c ounter-flow that surrounds the incoming stream jet of liquid from the inlet nozzle with steel displacing itself, after leaving this zone, along the up per free surface of the liquid. The addition of well designed baffles compl ements the action of the turbulence inhibitor to obtain a higher volume fra ction under a plug flow pattern giving a softer flow of liquid steel. Besid es, the positioning of baffles inside a tundish should be performed accordi ng to the steel flow rate.