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ⅠEmergency Plan for External Heater Failure of Catalytic Unit ⅠThe external heat extraction system of the catalytic cracking unit is a key equipment to achieve heat balance in the unit. Since the welds of the pipelines in this system have cracked in 8 places this year and have been covered, especially on November 23, the middle weld of the DN500 external hot water steam outlet main pipe cracked and leaked. After the cladding treatment, the amount of leakage at the condensation discharge point gradually increased, indicating that the cracks in the cladding were continuously expanding. Although the system pressure reduction operation is currently adopted, it cannot fundamentally solve the problem. If a larger problem occurs, it will have a great impact on production. In order to ensure the safe operation of the device, corresponding emergency plans have been made. Basic requirements: 1. Each member of the team is familiar with the boiler system process, including the exact location of the on-site valves. ； 2. Strengthen patrol inspections of key parts of external heat extraction, and report problems in a timely manner ； 3. There is a margin of 400 tons in the 2# and 3# catalyst tanks to ensure the unloading capacity in case of shutdown. ； 4. Keep the bypass process of raw material accidents smooth ； 5. Keep the oil slurry row in a normal standby state. 1. If the leakage is small, the hot water circulation pump will continue to run at the reaction position.: 1. Notify the production schedule and gradually reduce the mixing amount, which can reduce the residual oil to a lower value (about 20Nm3/h), reduce the main fan load, and control the riser feed to 120~130t/h ； 2. Close the sliding valve for external heat extraction and reduce the fluidizing air to below 1000m3/h. ； 3. Gradually remove the external heat from the system, vent and remove the pressure (less than 2.0MPa) ； 4. Due to the reduction in steam generation, the steam superheat temperature is high (higher than 450°C). Adjust it with cooling water. If it still cannot be controlled, the flue gas can be bypassed. ； 5. During the adjustment process, strictly follow the requirements of the process card, and over-temperature and over-pressure are strictly prohibited. ； 6. Contact us promptly to deal with leaks ； 7. After the leakage point is resolved, re-enable external heat extraction and resume normal production according to the steps. Quality position: 1. Due to the reduction in reaction volume, the load of each section of the fractionation tower is adjusted accordingly to ensure product quality. ； 2. The steam production of the boiler is reduced, the demineralized water volume is greatly reduced, and the related heat exchange load is reduced. The post-cooling temperature of diesel and oil slurry should be adjusted in a timely manner. ； 3. After the reaction part is restored, each fractionation operation gradually returns to normal. ； 2. If the leakage is large, it cannot be controlled and processed. 1. Notify the production schedule, reduce the load of the main fan, and stop the blending of residual oil as appropriate. ； 2. Close the sliding valve of the external heat collector to stop the fluidizing air from entering the system and reduce the internal load of the external heat collector to the minimum. ； 3. Stop the circulating water pump. If you cannot enter the site, contact the electrical power source to force the pump to stop. ； 4. Gradually remove the external heat from the system, vent and remove pressure, and cut off the boiler from the system. ； 5. If the leakage is large and it is impossible to get heat from the outside, cut out the 3# or 4# steam drum from the boiler at the same time (when the saturated steam reaches the temperature and pressure reduction valve, close it), and vent it from the 3# or 4# steam drum. ； 6. Change the flue gas part to the bypass to avoid overheating of superheated steam. ； 7. According to the specific situation, gradually cut out the hood ； 8. The bypass process for raw material inspection accidents is smooth, the main air blowback is turned on, and self-protection is ready to be activated. ； 9. Gradually cut the main air out of the system and operate at low flow. Be careful to enable the feed self-protection in advance and cut out the feed. ； 10. Check whether the on-site valve position is accurate ； 11. Increase the steam consumption of each reaction to the maximum, enable anti-flight, maintain the operation of the air compressor, operate the positive differential pressure of the reaction, and keep the regenerator dead bed warm. ； 12. Transfer the fresh catalyst from the 2# catalyst tank to the 1# catalyst tank, and then change the unloading process with the 3# catalyst tank to prepare three devices for unloading the agent. ； 13. According to the arrangement, merge the main wind into the system again and unload the catalyst. 14. The quality post will reduce the load or cut off the feed according to the reaction, and the load of each section of the fractionation tower will be adjusted accordingly or the feed will be cut off. Catalytic Workshop December 3, 2008