延迟焦化装置Z&J自动塔底盖机的应用与改进

The Application and Improvement of Z&J Auto Bottom Deheading Device in Delayed Coking Unit

自动底盖设备就其技术类型而言主要分为两种:一种在采用法兰密封技术的基础上增加液压元件,使之完成自动开关盖动作,以及施加、解除密封力,此技术进油方式仍为底部中心进料,以美国哈恩.克莱(Hahn&Clay)、福斯特惠勒(Foster Wheeler)公司产品为代表。另一种是2000年以后推出的采用阀门密封技术的自动底盖设备,此技术采用大口径平板闸阀完成塔底口自动开闭,进油采用侧进料方式,以Delta Valve公司、Z&J公司产品为代表。惠州炼油延迟焦化装置采用周期性除焦生产方式,生焦周期一般为18～24h,期间有换塔、小吹汽、大吹汽、小给水、大给水、放水、除焦、除焦塔试压、预热、切四通生焦等工序。该装置焦炭塔底卸盖系统采用4套德国Z&J公司双闸板闸阀式自动底盖机。结合装置应用实际,介绍此类底盖机的结构原理、控制系统与工作模式。运行实践表明,Z&J自动底盖机具有密封效果好,蒸汽耗量低,开关时间短,运行平稳的优点。

By the type of technology involved,automatic bottom deheading devices can be divided into two categories.The first category utilizes hydraulic components to open and close covers automatically and apply and relieve sealing force based on center of column bottom and Foster Wheeler.The other type flange sealing technology.In this type of technology,oil is still fed through the typical technologies in this category include products of Hahn ＆ Clay and of device was first released in 2000 and uses valve sealing technology.Such device uses a large-calibre flat gate valve to open and close the outlet at the bottom of column automatically and oil is fed via a side inlet.Typical products of this category include Delta Valve and Z＆J products. CNOOC Huizhou Refinery conducts decoking operations for its delayed coking unit periodically,whose typical eoking cycle is 18-24 hours.All procedures involved in a decoking operation include column switching,small steam blow,lare steam blow,small water supply,large water supply,water discharge,decoking,pressure testing for decoker,preheating and four-way valve switching for coke production.The deheading system at the bottom of the cokin drum of the unit uses four dual-disc,gate-valve automatic deheading devices from Germany＇s Z＆J company.Based on field application in units,this article describes the structure,working principle,control system and mode of operation of such deheading device.Field application shows that Z＆J＇s auto deheading device has many advantages such as good sealing effect,low steam consumption,short open/close time and stable operation.