Abstract: The blockage of feed nozzle of FCC feedstock will limit the processing capacity of the unit and decrease the light oil yield. In serious cases, it will cause unplanned shutdown of the plant. Previously, there is no mature on-line treatment method for the complete blockage of the nozzle. Through comprehensive application of pressurized opening technology and high pressure cleaning technology, the special packing seal box was developed, and the reasonable working process was set up to realize the online dredging of FCC feed oil nozzle blockage, which can avoid economic loss and safety risks caused by unit shutdown. This technology can be used for reference to other equipment and pipeline online cleaning and dredging, and has a wide application prospect.

Key words: catalytic cracking/FCC, nozzle, online dredging, hot tapping, water cannon