Flow Control Device Optimization Of One Conticaster With Single-strand 35 Tons Tundish

Clean steel is relatively popular content in metallurgical research. In order to produce high cleanliness steel, quality of liquid steel must be guaranteed before solidification. Tundish is a essential equipment in continuous casting, whose traditional functions are decompression, shunt and ensuring the steel continuous casting. As the last through container before steel solidificate, liquid steel quality in the tundish has a big influence on the quality of strand. In order to improve the purity of liquid steel, tundish technology is widely got attention. Among all the technologies, the most common technology is installing flow control device in the tundish. Based on the practical tundish for the prototype in one factory, metallurgical effect of different control device is studies by numerical simulation software, which provide s ideas to develop metallurgical effect of the tundish.Mathematical model is established based on the practical tundish size, the liquid flow residence time curves and temperature distribution of different control device are obtained by the software of Fluent. According to the liquid flow residence time curves, the response time, the peak time, the average residence time, the piston volume fraction and the dead zone volume fraction are analyzed. Flow residence time curve of the prototype tundish shows that the response time is 69.3s, the peak time is 442 s, the piston volume fraction is 35.91%, and the dead zone volume fraction is 18.86%. The results show that flow field is not reasonable in the prototype tundish, for the response time is short, the piston volume fraction is small and the dead zone volume fraction is big.Orthogonal experiment of multi-hole dam is studied, and the range analysis is conducted. Results show that the primary and secondary factors on the response time are respectively the guide hole elevation, diameter of the guide hole, distance between the upper hole and lower hole and the position of the multi-hole dam. The primary and secondary factors on the peak time and the dead zone volume fraction are respectively the guide hole elevation, diameter of the guide hole, the position of the multi-hole dam and distance between the upper hole and lower hole. The optimal flow control scheme is that the distance between the multi-hole dam center and the long nozzle center is 1550 mm, the diameter of the guide hole is 100 mm, the guide hole elevation is 35 angle, and the distance between the upper hole and lower hole is 240 mm. In the optimal flow control device, the response time is 92.9s,the peak time is 497 s, the piston volume is increased to 41.43%, the dead volume fraction is reduced to 14.33% and the piston volume and the dead zone volume fraction ratio is increased to 2.8917, which will be beneficial to improve the inclusion removal. Optimized multi-hole dam applies different casting rate. Metallurgical effect can be improved when deepening the height of turbulent inhibitor. But considering the service life of the bottom material, keeping the cavity height of turbulent inhibitor is 100 mm is more suitable. The circular turbulent inhibitor whose volume is same with the original one is recommended because the piston volume and the dead zone volume fraction ratio is increased to 2.9863.Results of temperature field show that temperature is not reasonable in the prototype tundish, for the low temperature zone is existed. After conducting orthogonal experiment optimization, the temperature field is evenly distributed. Different cavity height of turbulent inhibitor has little effect on the temperature field. And temperature field distribution is reasonable in the circular turbulent inhibitor.Considering the characteristics of flow field and temperature field distribution together, the optimal flow control scheme is the improved multi-hole dam with the circular turbulent inhibitor.