在烘烤盖+多功能顶枪的RH真空槽烘烤工艺中,多功能顶枪烘烤时存在诸多问题:燃气比例匹配失调、燃气流量控制系统PID参数整定困难、定枪位烘烤且枪位不合理和氮气保护气体使用不当。这时常导致安全事故、耐材烧损与开裂严重、燃气耗费量...在烘烤盖+多功能顶枪的RH真空槽烘烤工艺中,多功能顶枪烘烤时存在诸多问题:燃气比例匹配失调、燃气流量控制系统PID参数整定困难、定枪位烘烤且枪位不合理和氮气保护气体使用不当。这时常导致安全事故、耐材烧损与开裂严重、燃气耗费量较大、设备机械性能下降、维修率提高等不利现象发生。为此,中国重型机械研究院股份公司从燃气混合技术、PID流量调节技术、多串级闭环烘烤控制技术、变时长变流量多枪位循环加热技术和氮气保护技术等多方面进行研究,总结出新型RH真空槽高效顶枪烘烤技术。并应用于国内某钢厂的120 t RH真空槽烘烤工艺,生产顺利,作业率高,成本低,使用效果良好。展开更多
A water model and a high-speed video camera were utilized in the 300-t RH equipment to study the effect of steel flow patterns in a vacuum chamber on fast decarburization and a superior flow-pattern map was obtained d...A water model and a high-speed video camera were utilized in the 300-t RH equipment to study the effect of steel flow patterns in a vacuum chamber on fast decarburization and a superior flow-pattern map was obtained during the practical RH process. There are three flow patterns with different bubbling characteristics and steel surface states in the vacuum chamber： boiling pattern（BP）, transition pattern（TP）, and wave pattern（WP）. The effect of the liquid-steel level and the residence time of the steel in the chamber on flow patterns and decarburization reaction were investigated, respectively. The liquid-steel level significantly affected the flow-pattern transition from BP to WP, and the residence time and reaction area were crucial to evaluate the whole decarburization process rather than the circulation flow rate and mixing time. A superior flow-pattern map during the practical RH process showed that the steel flow pattern changed from BP to TP quickly, and then remained as TP until the end of decarburization.展开更多
In the Ruhrstahl-Heraeus （RH） refining process, liquid steel flow pattern in a ladle is controlled by the fluid flow behavior in the vacuum chamber. Potassium chloride solution and NaOH solution saturated with CO2 w...In the Ruhrstahl-Heraeus （RH） refining process, liquid steel flow pattern in a ladle is controlled by the fluid flow behavior in the vacuum chamber. Potassium chloride solution and NaOH solution saturated with CO2 were respectively used as a tracer to investigate the liquid and gas flow behaviors in the vacuum chamber. Principal compo nent and comparative analysis were made to show the factors controlling mixing and circulation flow rate. The liquid level and bubble behavior in the vacuum chamber greatly affect fluid flow in RH process. Experiments were performed to investigate the effects of liquid steel level, gas flow rate, bubble residence time, and gas injection mode on mixing, decarburization, and void fraction. The results indicate that the mixing process can be divided into three regions： the flow rate affected zone, the concentration gradient-affected zone, and their combination. The liquid steel level in the vacuum chamber of 300 mm is a critical point in the decarburization transition. For liquid level lower than 300 mm, liquid steel circulation controls decarburization, while for liquid level higher than 300mm, bubble behavior is the main controlling factor. During the RH process, it is recommended to use the concentrated bubble injection mode for low gas flow rates and the uniform bubble injection mode for high gas flow rates.展开更多
文摘在烘烤盖+多功能顶枪的RH真空槽烘烤工艺中,多功能顶枪烘烤时存在诸多问题:燃气比例匹配失调、燃气流量控制系统PID参数整定困难、定枪位烘烤且枪位不合理和氮气保护气体使用不当。这时常导致安全事故、耐材烧损与开裂严重、燃气耗费量较大、设备机械性能下降、维修率提高等不利现象发生。为此,中国重型机械研究院股份公司从燃气混合技术、PID流量调节技术、多串级闭环烘烤控制技术、变时长变流量多枪位循环加热技术和氮气保护技术等多方面进行研究,总结出新型RH真空槽高效顶枪烘烤技术。并应用于国内某钢厂的120 t RH真空槽烘烤工艺,生产顺利,作业率高,成本低,使用效果良好。
基金financially supported by the National Natural Science Foundation of China (No.51704203)the PhD Early Development Program of Taiyuan University of Science and Technology (Nos. 20152008, 20152013, and 20152018)+2 种基金Shanxi Province Science Foundation for Youths (No. 201601D202027)Key Project of Research and Development Plan of Shanxi Province (Nos. 201603D111004 and 201603D121010)NSFC-Shanxi Coal Based Low Carbon Joint Fund (No. U1510131)
文摘A water model and a high-speed video camera were utilized in the 300-t RH equipment to study the effect of steel flow patterns in a vacuum chamber on fast decarburization and a superior flow-pattern map was obtained during the practical RH process. There are three flow patterns with different bubbling characteristics and steel surface states in the vacuum chamber： boiling pattern（BP）, transition pattern（TP）, and wave pattern（WP）. The effect of the liquid-steel level and the residence time of the steel in the chamber on flow patterns and decarburization reaction were investigated, respectively. The liquid-steel level significantly affected the flow-pattern transition from BP to WP, and the residence time and reaction area were crucial to evaluate the whole decarburization process rather than the circulation flow rate and mixing time. A superior flow-pattern map during the practical RH process showed that the steel flow pattern changed from BP to TP quickly, and then remained as TP until the end of decarburization.
基金Item Sponsored by National Natural Science Foundation of China(51404022)Doctoral Fund of Ministry of Education of China(20130006110023)Ph.D Early Development Program of Taiyuan University of Science and Technology of China(20152008,20142001)
文摘In the Ruhrstahl-Heraeus （RH） refining process, liquid steel flow pattern in a ladle is controlled by the fluid flow behavior in the vacuum chamber. Potassium chloride solution and NaOH solution saturated with CO2 were respectively used as a tracer to investigate the liquid and gas flow behaviors in the vacuum chamber. Principal compo nent and comparative analysis were made to show the factors controlling mixing and circulation flow rate. The liquid level and bubble behavior in the vacuum chamber greatly affect fluid flow in RH process. Experiments were performed to investigate the effects of liquid steel level, gas flow rate, bubble residence time, and gas injection mode on mixing, decarburization, and void fraction. The results indicate that the mixing process can be divided into three regions： the flow rate affected zone, the concentration gradient-affected zone, and their combination. The liquid steel level in the vacuum chamber of 300 mm is a critical point in the decarburization transition. For liquid level lower than 300 mm, liquid steel circulation controls decarburization, while for liquid level higher than 300mm, bubble behavior is the main controlling factor. During the RH process, it is recommended to use the concentrated bubble injection mode for low gas flow rates and the uniform bubble injection mode for high gas flow rates.
