伊朗L.M.I.公司卧式连续退火炉控制系统

来源期刊：冶金自动化2009年第3期

论文作者：唐锴 韩滔 胡玲艳

文章页码：29 - 32

关键词：退火炉； PLC； 控温系统

Key words：annealing furnace； PLC； temperature control system

摘    要：针对伊朗L.M.I.公司42 m卧式连续退火炉结构特点及退火工艺要求,以西门子S7-400 PLC为核心控制设备,实现球墨铸铁管退火过程的全程自动控制。介绍了退火工艺曲线的设定机理、系统构成和控温系统。该炉在炉长方向上分为加热、保温、急冷和缓冷四个炉段。文章针对不同炉段的控温特性,重点分析了各炉段的控温方式。加热段采取连续燃烧控制方式;急冷段通过间接水冷方式实现铸管的迅速冷却;保温段和缓冷段采用脉冲燃烧控制方式,该方式可使铸管受热均匀,提高加热效率,本系统脉冲控制完全通过自主开发的PLC程序实现。实际运行结果表明,整个系统性能稳定,温度控制精度高,很好地满足了工艺上的要求。

Abstract: According to structure characteristics and annealing requirement of 42 m horizontal continuous annealing furnace in Iran L.M.I.Co.,Ltd.,Simatic S7-400 PLC is used as the kernel control unit to realize automatic control of whole annealing process for nodular cast iron pipe.Setting principle of temperature curve,system construction and temperature control modes are introduced.The furnace is horizontally divided into four zones.They are heating zone,holding zone,rapid cooling zone and slow cooling zone.Temperature is the key parameter of the whole system,so different temperature control modes are analyzed according to four furnace zones.Continuous burning control is used in heating zone.In rapid cooling zone,rapid cooling of cast iron pipe is achieved by indirect water cooling mode.In holding and slow cooling zones,pulse-burning control is applied.Under the pulse control mode,cast pipe can be equally heated and thermal efficiency can be improved.In this project,pulse control program is developed with PLC by oneself.Actual application shows that furnace performance is stable and temperature control accuracy is high.Whole system meets the need of technological process perfectly.