索德伯格电极热应力控制
详细信息 查看官网全文
- 英文论文题名：CONTROLLING THERMAL STRESS IN S?DERBERG ELECTRODES
- 论文作者：B.Larsen ; H.Feldborg ; S.A.Halvorsen
- 英文论文作者：B.Larsen ; H.Feldborg ; S.A.Halvorsen ; Elkem Carbon AS ; Vaagsbygd ; Teknova AS ; Tordenskjoldsgate 9
- 年：2017
- 作者机构：Elkem Carbon AS,Vaagsbygd;Teknova AS, Tordenskjoldsgate 9;
- 会议召开时间：2017-05-05
- 会议录名称：铁合金矿热炉电极炉衬及环境保护煤气综合利用技术论文集
- 语种：中文
- 分类号：TF06
- 学会代码：GYBW
- 会议名称：2017年铁合金矿热炉电极炉衬及环境保护煤气综合利用技术座谈会
- 会议地点：中国宁夏银川
- 主办单位：钢铁研究总院、中国铁合金技术网、《中国冶金》编辑部
- 学会名称：北京钢研柏苑出版有限责任公司
- 页数：11
- 文件大小：1631k
- 原文格式：D
- 会议级别：全国
摘要
用于生产各种铁合金以及铂、镍、铜等金属的矿热炉(SAF)通常配备索德伯格电极。在正常负荷下良好运行的炉子断电极的风险是很小的。但是所有炉子都需要停炉检修,有些炉子由于电价原因避峰生产需要经常停炉。电极在这种温度动态变化的情况下会产生热应力,电极能够承受这些热应力而不断裂是非常重要的。最糟糕的情形是电炉运行事故或非计划停炉,这会导致电极内部产生剧烈的热应力从而增加断电极风险。我们可以从某种程度上人为的影响停炉过程中电极所承受的热应力,因此也可以降低电极断裂的风险。多年来埃肯碳素使用数学模型ElkemD和ElkemT分析停起炉过程中的电极的温度和应力。这些数学模型可以帮助我们理解电极应力形成的机理,同时提供参考使我们用最优的方法进行停起炉操作。用最优的停起炉程序可以减少因断电极而造成的停炉时间,从而提高电炉运行效率。停炉时间的长短决定了电极应力的大小,最优的停起炉程序取决于停炉时间。短时间停炉后可以快速的恢复负荷,长时间停炉后则需要慢一点恢复负荷。本文探讨了影响电极应力的各种参数,例如电极尺寸、电极电流、停炉操作、停炉时间和恢复负荷速率等。用很有启发的各种图表说明不同停炉时间、不同的负荷恢复速率下电极所承受的最大应力,以帮助我们更好的理解停起炉操作应当如何进行。
Submerged arc furnaces(SAF) for production of various ferroalloys, platinum, nickel-or copper matte are most often equipped with S?derberg electrodes. For a well operated furnace, the risk of having an electrode breakage during normal load is quite small. But all furnaces need shutdowns for planned maintenance, and some furnaces are regularly stopped for cost savingreasons during energy peak hours.Such dynamic temperature conditions will provoke thermal stresses in the electrodes, and it is important that the electrodes can withstand these stresses without breaking. The worst case is an operating accidentor unplanned shutdown; conditions that can result in severethermal stresses andincreased risk for electrode breakage.It is, to some extent, possible to influence the level of stresses during a shutdown and hence it is also possible toreduce the risk of having an electrode breakage. Elkem Carbon has for many years used mathematical models, ElkemD and ElkemT, for temperature and stress analysisduring shutdowns. These toolsmake it possible to understand the mechanism of stress formationsand to give recommendations on how to handle furnace stoppages in the best possible way. Using optimized shutdown procedures will give less down time due to breakages, and hence a more efficient furnace operation. The duration of ashutdown determinesthe stress levels. Anoptimized shutdown procedure therefore dependson the shutdown duration. Short shutdowns should be recovered fast, while longer shutdowns need longerrecovery times.This paper discusses how the stresses are influenced by various parameters such as electrode size and current, "powering down" practice, shutdown duration and recoverytime. Maximum stress versus shutdown duration and recovery time are presented in informative diagrams making it easier to understand how various shutdowns should be handled.
Submerged arc furnaces(SAF) for production of various ferroalloys, platinum, nickel-or copper matte are most often equipped with S?derberg electrodes. For a well operated furnace, the risk of having an electrode breakage during normal load is quite small. But all furnaces need shutdowns for planned maintenance, and some furnaces are regularly stopped for cost savingreasons during energy peak hours.Such dynamic temperature conditions will provoke thermal stresses in the electrodes, and it is important that the electrodes can withstand these stresses without breaking. The worst case is an operating accidentor unplanned shutdown; conditions that can result in severethermal stresses andincreased risk for electrode breakage.It is, to some extent, possible to influence the level of stresses during a shutdown and hence it is also possible toreduce the risk of having an electrode breakage. Elkem Carbon has for many years used mathematical models, ElkemD and ElkemT, for temperature and stress analysisduring shutdowns. These toolsmake it possible to understand the mechanism of stress formationsand to give recommendations on how to handle furnace stoppages in the best possible way. Using optimized shutdown procedures will give less down time due to breakages, and hence a more efficient furnace operation. The duration of ashutdown determinesthe stress levels. Anoptimized shutdown procedure therefore dependson the shutdown duration. Short shutdowns should be recovered fast, while longer shutdowns need longerrecovery times.This paper discusses how the stresses are influenced by various parameters such as electrode size and current, "powering down" practice, shutdown duration and recoverytime. Maximum stress versus shutdown duration and recovery time are presented in informative diagrams making it easier to understand how various shutdowns should be handled.
引文
[1]R.Innv?r,L.Olsen,A.Vatland;“Operational Parameters for S?derberg Electrodes From Calculations,Measurements and Plant Experience”,Mintek 50,Johannesburg 1984
[2]B.Larsen,R.Birkeland,“Improving S?derberg Electrode Material by Applying Fracture Mechanics”,Euro Carbon 2000,Berlin,pp371-372.
[3]R.Innv?r,L.Olsen;“Practical use of mathematical models for S?derberg Electrodes”.Proceedings of the 37th Electric Furnace Conference,Detroit,1979
[4]A.G.Arnesen,S.?kstad,R.Innv?r,L.Olsen;“Operation of S?derberg Electrodes”.ILAFA Ferroalloy Congress,Acapulco 1978.
[5]B.Larsen,H.Feldborg,S.A.Halvorsen;"Controlling thermal stress during shutdown of S?derberg electrodes".INFACON XIII,2013.
[2]B.Larsen,R.Birkeland,“Improving S?derberg Electrode Material by Applying Fracture Mechanics”,Euro Carbon 2000,Berlin,pp371-372.
[3]R.Innv?r,L.Olsen;“Practical use of mathematical models for S?derberg Electrodes”.Proceedings of the 37th Electric Furnace Conference,Detroit,1979
[4]A.G.Arnesen,S.?kstad,R.Innv?r,L.Olsen;“Operation of S?derberg Electrodes”.ILAFA Ferroalloy Congress,Acapulco 1978.
[5]B.Larsen,H.Feldborg,S.A.Halvorsen;"Controlling thermal stress during shutdown of S?derberg electrodes".INFACON XIII,2013.