Physical And Numerical Simulation On Fluid Flow In A Six-Strand T-type Continuous Casting Tundish

In the present paper, based on a six-strand continuous casting tundish for circular billets in a certain plant the physical and mathematical models were established to study the effect of control devices on fluid flow characteristic by anaysising the parameters obtained from the residual time distribution curve in tundish. The optimal results could provide theroticial direction for actual production. Under the present experimental conditions it came to the conclusions as followed.(1) The results derived from numerical simulation agreed well with that obtained from physical modeling. The agreement confirmed the validity of setups of boundary condition and mesh generation.(2) For the original tundish with A-type TI (Turbulence Inhibitor), the turbulence kinetic energy on top of inlet zone was higher than that on other zones which is responsible for reoxidation and slag entrapment. By using the crossed V-type baffles, the short circuiting flow occured beside nozzle3#. The fluid ejected from baffle holes tended to flow along the walls that caused the extension of the inactive area and the dead volume fraction reaches to33%. The fluid flow through nozzle1#,2#and3#existed serious difference and the dispersion of mean residual time between outlet1#and2#reached up to44s.(3) After using the optimal flow control devices, the residence time of fluid in the tundish increased from the original value576s to700s, as well the dead volume fraction decreased to20%. The dispersion of different outlets was limited within20s. As a result, the fluid flow characteristics were significantly improved.(4) The turbulent flows were restricted within the inlet region by adopting the B-type or C-type TI. It’s beneficial on inclusion collision, agglomeration and flotation in this area.(5) While using the improved V-type baffles which were not intersected, the short circuiting flow near the3stream region was eliminated compared with that using the original crossed V-type baffles. Melt flow of regions on the downstream side of the baffles and near the end wall became active. The new-designed baffles also activated the fluid flow ejected from the baffle holes and developed the flow along free surface which prompted inclusion removal during continuous casting process.(6) The position of dams greatly effected fluid fow uniformity during casting process. Placing dams in the pouring area between outlets2#and3#, the short circuit flow was eliminated, and the fluid flow near outlet2#turn to flow towards the free surface. Fluid flow between different streams became uniform and the fluid flow characteristics were improved greatly after using the optimal control devices.