Leakage in the external heat exchanger tube bundle
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How should severe leakage in the external heat exchanger tube bundle and significant slippage of the regenerator bed material be dealt with? Can I just cover the bed directly?
A stagnant bed, with a gradual drop in bed temperature, and the flow of water from external heat packs into the bed layer can lead to problems with the bed layer and the sludge.
After the bed is sealed, the temperature can no longer be controlled; will this eventually lead to water affecting the catalyst and sludge?
It is very likely that the water that cannot be completely vaporized is what causes the sludge to form. Therefore, if a bed suppression method is adopted, the pressure relief of the external heat exchanger’s steam drum must be carried out quickly, and the water inside the external heat exchanger should be drained promptly after pressure relief. After resuming operation, significant loss of the catalyst is inevitable; it is necessary to promptly add large amounts of balancing agents.
Have such incidents occurred there? How did you handle it? If there is a leak in the tube bundle, will the catalyst enter the drum?
It has happened that operations were halted and the catalyst was removed when the external heat transfer tubes leaked; there was no catalyst entering the steam drum, which prevented sludge formation. During the removal of the catalyst, any sludge formed as a result of this was also completely removed.
Could you give some guidance on the general approach? Thank you
Just follow the normal shutdown procedures. It is important to prevent the external heat transfer tubes from overheating and deforming when the bed temperature is high, and at the same time to avoid water from entering and causing clogging when the bed temperature is low. A little mud can be cleared out after the manhole is finally opened.
Following the normal shutdown procedures, won’t the long processing time and severe leakage in the regenerator have an impact on the flue gas turbine?
Whether feeding is cut off or not, it is necessary to locate and remove the leaking tube bundle to prevent a large amount of catalyst from accumulating as sludge; try to keep the material in a fluidized state as much as possible.
Just remove it externally, isn’t that enough? As for a stuffy bed?