Abstract: Delayed coking unit is an important equipment to improve production factor of light oil. The bottom and top unheading blind plates of delayed coking units and other accessories that refineries have used for many years have a series of problems, such as complicated procedures for operation, low automation degree, negative impact on safety and environmental protection, and high cost for operation and maintenance. Therefore, substitute products are developed, such as DN1500 bottom unheading valve and DN900 top unheading valve. They are designed have a plane gate valve structure and adopt floating hard sealing and steam accessory sealing. They are operated by control chamber and onsite operational station. The accessories of the device use heat-resistant steel as main material. The surface of valve plate comes under nitriding treatment. The depth of nitriding layer is ≥0.5mm, the flatness of valve plate surface is ≤0.05mm and the roughness of the surface is <Ra0.8, deposit welding on sealing surface required cemented carbide. Currently, dozens of such valves have been used at home and regarded as good for safety and environmental protection, low in labor intensity, high in automation level and remarkable in economic performance.

Key words: delayed coking, bottom valve, top valve, technological characteristics, application results

摘要： 延迟焦化装置是提高轻质油收率的重要设备,炼油厂多采用的延迟焦化装置焦炭塔底、塔顶盲盖及辅助装置塔底、塔顶盖机存在操作繁琐、自动化程度低、不利于安全及环保、运行成本及维修费用高等问题,为此研制了替代产品DN1500焦化塔底阀、DN900塔顶阀。平板闸阀结构设计,采用浮动硬密封加蒸汽辅助密封,实施控制室和现场操作站两级授权操作,装置零部件采用耐热钢为主体材料,阀板表面进行渗氮处理,渗氮层深度≥0.5mm,阀板表面平面度≤0.05mm,表面粗糙度<Ra0.8,密封面均要求堆焊硬质合金。目前国内已投用几十台,应用中安全性高、环保性好、劳动强度降低、自动化水平提高,经济效益显著。

关键词: 延迟焦化, 焦化塔底阀, 焦化塔顶阀, 技术特点, 应用效果