催化裂化主风机组停机处理过程中的次生风险分析

An Analysis of Secondary Risks during Downtime of Main Air Blower Unit

洛阳石化二号催化裂化装置主风机组停机及恢复正常生产过程中,通过采取定期关小塞阀、气压机组切出系统、沉降器压力略高于再生器压力等措施,消除了反再两器互窜的风险;通过关闭现场外取热提升风、流化风手阀等措施,消除了外取热催化剂倒窜的风险;在解决汽提段流化不畅被迫停工问题上,一是在两器流化前,采用较高的再生密相温度;二是在两器流化过程中,先将催化剂充实待生立管,然后再"数次开大、关小两段汽提蒸汽进行疏通,兼用快速降低反应压力"等措施,解决了汽提段流化不畅问题;通过采取余热炉不改旁路、走正线、中压过热蒸汽倒窜低压蒸汽等措施,确保异常工况下余热回收系统正常运行,烟气达标排放;针对脱硫脱硝塔温度逐渐升高的风险,采取较大补水量及排放量,置换塔内温度较高的浆液,避免脱硫脱硝塔内温度积聚,设备超温损坏。通过采取以上措施,确保了装置始终处于安全、环保、平稳状态。

During the oyang Company＇ s No.2 downtime and resumption of production of the main air blower unit of Sinopec Lu- catalytic cracking plant,technicians took measures to eliminate the risks of reactor and regenerator intermingling,including periodically shutting down small plug valves and air pressure unit cut-out system and setting the pressure of the settler closing off-site heat-removing air flow increasing and slightly higher than the pressure of the regenerator.By fluidizing air had valves,they eliminated the risk of areflux of externally heat-removing catalyst.As a solution to the forced shutdown caused by poor fluidization in the stripping section,they adopted a relatively high regeneration dense-phase temperature ahead of fluidization in the reactor and regenerator,while filling up the regeneration standpipe with catalyst during fluidization of the reactor and regenerator before turning up and down the two-segment stripping steam several times,cou- pled with measures to quickly reduce reaction pressure.Normal operation of the residual heat recovering sys-tern was guaranteed and flue gas met emission standard under abnormal operating conditions by giving up a bypass line and choosing the main line for the residual heat boiler and substituting medium-pressure over- heated steam for low-pressure steam.To avoid the risk tion and denitrification columns,large water supplement temperature fluids inside the columns,to prevent equipment.The above measures ensure the plant of gradually elevating temperatures in the desulfuriza- and drain volumes were used to replace the high- temperature buildup inside the columns,which may damage has remained in a safe,environmentally friendly and stableworking state.