Repeatedly, some branches of the main air distribution pipe suddenly fell off, eventually leading to the shutdown of the device.

Thread Content

Frequently, some branches of the main air distribution pipe suddenly fell off, eventually causing the unit to stop production. Frequently, some branches of the main air distribution pipe suddenly fell off, causing part of the main air to pass through. Frequently, the bed fluidization was not good, and the scorching effect was poor. Moreover, part of the coke was brought to the dilute phase by the through-passing main air and continued to burn, causing the dilute phase temperature to overheat, up to 740°C or above, and then the hood inlet temperature exceeded the standard. At the same time, the first bed was not fully burned, which also caused a large amount of coke to be brought to the second bed and continued to be burned. The temperature of the second bed exceeded the standard, reaching 750°C. The proportion of straight wax in the raw material was increased, which reduced the amount of coke generated in the reaction. The operation was alleviated by reducing the fresh feed, reducing the main air volume, using terminators, reducing the amount of external heat gas generated, and reducing the amount of MGD gasoline. Due to conflicts such as the company's crude oil balance and equipment supply time, the company requires the equipment to try its best to maintain production. In order to prevent other derivative accidents from occurring under abnormal production conditions, the workshop has formulated the following operating principles: a. Repeat the main air volume as much as possible to avoid damaging the fluidization state of the main air distribution pipe and deteriorating the operation. If you want to adjust, you need to adjust it slowly. Each time you adjust the air volume, it should be 200nm3/h. ； b. Ensure that the pressure of the three devices is stable and controlled within the specified indicators. ； c. Prevent repeated over-temperature and hood inlet over-temperature. If over-temperature occurs, you can adjust the amount of stripping steam, add CO combustion accelerant (required to add it once an hour per shift), etc. ； d. Prevent secondary over-temperature and strictly control secondary oxygen content within the target. If the regenerated scorching capacity cannot be improved, measures can be taken to reduce scorch generation.: For example, reducing feed materials, recycled oil and MGD recycled gasoline, etc. ； e. Ensure that the liquid level in the fractionating tower is normal, and prohibit the liquid level from being too high, which may cause reaction pressure. The liquid level of the fractionating tower can be controlled by increasing the amount of oil slurry thrown out and reducing the amount of oil slurry circulating, but it must be ensured that the temperature of the oil slurry thrown out is within the index and the temperature of the gas-liquid phase of the fractionating tower is within the index. The starting conditions further deteriorated, the density of the semi-regenerated standpipe fluctuated, the reaction temperature fluctuated greatly, and the vibration of the external heat cylinder and connected pipelines increased, affecting the safe production of the device. For this reason, on June 23, the company leaders cut off the external heat extraction, kept the pressurized air in each channel just excessive, and at the same time modified some operating indicators.: Hood inlet temperature ≯700℃ ； Double and double density temperature ≯760℃. Through adjustments, the situation has improved, but there is still the possibility of further deterioration. Therefore, in order to protect the hood and equipment, the workshop requires operators to decisively cut off the feed when the conditions deteriorate and the conditions of various parts fluctuate significantly, exceed the specified indicators, and become uncontrollable. At the same time, contact relevant personnel to switch to the backup machine and stop work according to the normal stoppage plan. According to the company's arrangements, switch the hood to standby operation. 26th 8: Starting from 16:00, the quantity reduction will be started according to the shutdown requirements, 9: Stop the air compressor at 05 minutes, 9: Cut off the feed at 23 minutes. According to the steps of the shutdown plan, react to transfer the agent, unload the agent, fractionate and stabilize the oil, and clean the line. The device was completely shut down on June 30, 8: 00 is handed over to the maintenance unit, and the device enters a comprehensive overhaul period. This post was last edited by clhmm on 2009-2-4 19:54 ]