Optimization of flow, heat transfer and inclusion removal behaviors in an odd multistrand bloom casting tundish

Abstract

The steel flow, heat transfer, and inclusion removal behaviors in a five-strand bloom tundish for five baffles and two types of turbulence inhibitors (TIs) were investigated by a multiphysical model to enhance the consistency among the strands and the purity of molten steel. Water model experiments were conducted to verify the simulated results of flow and residence time distribution (RTD). The results showed that the simulated steel flow and RTD curves were basically consistent with those of the experiments. Compared to original conditions, the total residence time reaches 595.0 s, and the volume of the plug region increases by 4.8%, while the volume of dead zone decreases by 0.2% when applying the optimized baffle and TI. In addition, the response and residence times at the 3rd strand increase by 42.5 s and 264.6 s, the total average standard deviation decreases to 0.0057. Meanwhile, the maximum temperature drop decreases from 28.6 K to 22.8 K, and the temperature difference among strands decreases from 3.7 K to 1.4 K. The inclusions removal rate increases by 0.9% to 8.3% with diameters ranging from 10 μm to 100 μm and reaches 94.4% at 100 μm. Furthermore, the qualification rates of flaw detection and nonmetallic inclusions in high rails after optimization increase from 97.94% to 98.73% and from 97.3% to 99.1%, respectively, and the consistency among the strands is apparently enhanced.