Reasons for catalyst loss
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I would like all the teachers to analyze what the reasons are for the loss of catalyst in the regenerator due to flue gas leakage, what the main phenomena occur during operation, and how such issues can be prevented, addressed, and dealt with.
The catalyst that leaks from the flue comes from the regenerator, and there are various reasons for this: 1) Equipment-related issues: The wing valves on the material legs do not close properly； The peeling of the lining causes the material leg to not close properly ； 2) Process reason: Excessively high linear velocity at the separator inlet ； Accidental steam leakage with water present ； Loose steam carries water ； 3) Excessively high content of catalyst sub-components ； The wear index of the catalyst is too high
Actual experience: (1) Blockage (partial blockage) in the feed leg of the centrifuge. Due to coking in the dead zone where the anti-backflow cone of the centrifuge meets its lining, a large piece of coke broke off and fell into the feed leg, causing partial blockage. As a result, there was severe loss of catalyst in the system, and it became impossible to maintain the proper level of catalyst; therefore, operations had to be stopped urgently for repairs. (2) The ring weld portion of the leg in the dilute-phase region is penetrated, the material seal of the cyclone separator fails, and catalyst is lost ； Later, attempts were made to raise the level of material in the settler in order to continue operations until maintenance could be carried out; as a result, the welds wore through, creating holes in a shuttle-shaped pattern. Reminder: (1) If the centrifuge does not function properly, it can cause severe loss, but catalyst particle size analysis will show that it is similar to the particle size distribution of the balancing agent. (2) The catalyst is broken inside the riser, and the material that flows out is mainly fine powder.
Excessive main air volume, wear of the main air distribution pipes, too high line speed, and too low material level can all cause regenerative agent leakage.
Large fluctuations in regeneration pressure can also cause leakage! ! !
The catalyst that leaks from the flue comes from the regenerator, and there are various reasons for this: 1) Equipment-related issues: The wing valves on the material legs do not close properly； The peeling of the lining causes the material leg to not close properly ； 2) Process reason: Excessively high linear velocity at the separator inlet ； Accidental steam leakage with water present ； Loose steam carries water ； 3) Excessively high content of catalyst sub-components ； The catalyst wear index is too high; 4 – There is an excessive amount of steam in the regeneration system or there is steam leakage
As a supplementary point, the high pressure in the regenerator results in a high linear velocity of the catalyst within the centrifuge; the centrifuge is not able to separate the catalyst in time, causing it to enter the waste heat boiler and flue gas system
I learned a lot; there are indeed some situations that deserve attention.