The problem of coking in the re-refining tank
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During the maintenance of the re-refining tank, it was found that there was a significant amount of coking inside the tank. What caused this?
Does that mean the bottom of the fractionation tower, the desuperheating section, and the lower two trays are also severely coked?
If the re-refining tank cokes, then the lower trays of the distillation column will also coke.
Is it Jiaozi? Or impurity precipitates?
Personally, I don’t think it’s coking; rather, it’s something similar to a gel-like substance, very sticky!
If coking occurs during re-refining. That zigzag baffle on the second layer of the distillation tower should also be there.
Coking is unlikely; it’s probably an unstable operation that causes asphalt to enter the re-refining process, resulting in the formation of insoluble components
It is indeed coking; if it weren’t coking, I wouldn’t have raised this issue for everyone to discuss
How large is the coke lump? Do you mean the re-refining tank is the oil rejection tank during oil circulation?
It is drawn from the side line of the fractionation tower to the re-refining tank, where the slurry is circulated.
Check whether it is caused by uneven heating, poor flow, or excessively high oil temperature. Since coking was detected during your maintenance work, there must also be coking at the bottom of the distillation tower