The available studies in the literature on mathematical modeling of the vacuum circulation (RH) refining process of molten steel have briefly been reviewed. The latest advances obtained by the author with his research...The available studies in the literature on mathematical modeling of the vacuum circulation (RH) refining process of molten steel have briefly been reviewed. The latest advances obtained by the author with his research group have been summarized. On the basis of the mass and momentum balances in the system, a new mathematical model for decarburization and degassing during the RH and RH KTB refining processes of molten steel was proposed and developed. The refining roles of the three reaction sites, i.e. the up snorkel zone, the droplet group and steel bath in the vacuum vessel, were considered in the model. It was assumed that the mass transfer of reactive components in the molten steel is the rate control step of the refining reactions. And the friction losses and drags of flows in the snorkels and vacuum vessel were all counted. The model was applied to the refining of molten steel in a multifunction RH degasser of 90 t capacity. The decarburization and degassing processes in the degasser under the RH and RH KTB operating conditions were modeled and analyzed using this model. Besides, proceeded from the two resistance mass transfer theory and the mass balance of sulphur in the system, a kinetic model for the desulphurization by powder injection and blowing in the RH refining of molten steel was developed. Modeling and predictions of the process of injecting and blowing the lime based powder flux under assumed operating modes with the different initial contents of sulphur and amounts of powder injected and blown in a RH degasser of 300 t capacity were carried out using the model. It was demonstrated that for the RH and RH KTB refining processes, and the desulphurization by powder injection and blowing in the RH refining, the results predicted by the models were all in good agreement respectively with data from industrial experiments and practice. These models may be expected to offer some useful information and a reliable basis for determining and optimizing the technologies of the RH and RH KTB refining and desulphurization by powder injection and blowing in the RH refining and for controlling the processes.展开更多
With the strong demand for the development of automobile sheets, tin plates, household appliances, silicon steel, pipeline steel and other products as well as for the quality improvement of steel products, remarkable ...With the strong demand for the development of automobile sheets, tin plates, household appliances, silicon steel, pipeline steel and other products as well as for the quality improvement of steel products, remarkable progress has been made in RH refining technology and equipment design since Baosteel began production more than 20 years ago. The vacuum degassing ratio of Baosteel has jumped from 35% in the initial stage when Baosteel began production, to the current ratio of approximately 60%, and will soon reach 75% in the near future. The independent innovations in RH refming technology in Baosteel, such as RH equipment optimization, vacuum decarburization, inclusion control, deoxidation, desulfurization, rhythm adjustment between primary steelmaking and continuous casting, the high efficiency of the RH refining process, and other aspects of RH technology, have all effectively met the requirements of developing new steel products, quality improvement and logistical control. Complete sets of RH equipment and refining technology have been successfully exported to the domestic steel plants. In the future, Baosteel will make further efforts to improve efficiency, stabilize production and quality, and realize special line production, so that the RH degasser will play a greater role in Baosteel.展开更多
文摘The available studies in the literature on mathematical modeling of the vacuum circulation (RH) refining process of molten steel have briefly been reviewed. The latest advances obtained by the author with his research group have been summarized. On the basis of the mass and momentum balances in the system, a new mathematical model for decarburization and degassing during the RH and RH KTB refining processes of molten steel was proposed and developed. The refining roles of the three reaction sites, i.e. the up snorkel zone, the droplet group and steel bath in the vacuum vessel, were considered in the model. It was assumed that the mass transfer of reactive components in the molten steel is the rate control step of the refining reactions. And the friction losses and drags of flows in the snorkels and vacuum vessel were all counted. The model was applied to the refining of molten steel in a multifunction RH degasser of 90 t capacity. The decarburization and degassing processes in the degasser under the RH and RH KTB operating conditions were modeled and analyzed using this model. Besides, proceeded from the two resistance mass transfer theory and the mass balance of sulphur in the system, a kinetic model for the desulphurization by powder injection and blowing in the RH refining of molten steel was developed. Modeling and predictions of the process of injecting and blowing the lime based powder flux under assumed operating modes with the different initial contents of sulphur and amounts of powder injected and blown in a RH degasser of 300 t capacity were carried out using the model. It was demonstrated that for the RH and RH KTB refining processes, and the desulphurization by powder injection and blowing in the RH refining, the results predicted by the models were all in good agreement respectively with data from industrial experiments and practice. These models may be expected to offer some useful information and a reliable basis for determining and optimizing the technologies of the RH and RH KTB refining and desulphurization by powder injection and blowing in the RH refining and for controlling the processes.
文摘With the strong demand for the development of automobile sheets, tin plates, household appliances, silicon steel, pipeline steel and other products as well as for the quality improvement of steel products, remarkable progress has been made in RH refining technology and equipment design since Baosteel began production more than 20 years ago. The vacuum degassing ratio of Baosteel has jumped from 35% in the initial stage when Baosteel began production, to the current ratio of approximately 60%, and will soon reach 75% in the near future. The independent innovations in RH refming technology in Baosteel, such as RH equipment optimization, vacuum decarburization, inclusion control, deoxidation, desulfurization, rhythm adjustment between primary steelmaking and continuous casting, the high efficiency of the RH refining process, and other aspects of RH technology, have all effectively met the requirements of developing new steel products, quality improvement and logistical control. Complete sets of RH equipment and refining technology have been successfully exported to the domestic steel plants. In the future, Baosteel will make further efforts to improve efficiency, stabilize production and quality, and realize special line production, so that the RH degasser will play a greater role in Baosteel.
