Reformation and regeneration experts incoming

The threshold is high enough! I shouldn’t have come in. Even a non-expert can answer your question: It should be emphasized that the reduction zone also needs to have an appropriate material level in order for the catalyst to carry out the two stages of reduction more effectively. 1. If the material level is very low, the catalyst delivered by the self-regenerating lift pipeline will fall to the bottom of the reduction section at a high speed due to gravity and positive pressure, and then flow back into the reactor through the delivery pipe; as a result, the reduction process cannot be completed. 2. If the material level is too high, it will block the catalyst inlet riser, hindering the delivery of catalyst. 3. On the one hand, the level of the reduced material level will indirectly affect the dust removal system; the reason for this is not explained here. Therefore, it is necessary to install such an interlock system to shut down the plant using regenerative heat.

The poster is referring to the separation hopper, not the level of material in the reduction section

This post was last edited by che7420 on 2010-8-16 10:06. I misread it. The level of material in the separation hopper has a direct impact on the dust removal efficiency of the dust removal system. Poor dust removal effect, causing clogging of the Johnson screen. Conversely, good catalysts are blown out.

Could you be more specific about what was said upstairs? Is it the poor dust removal effect when the material level is low, or is it the poor effect when the level is high? If you say that a high material level affects catalyst dust removal, I find that reasonable, because a high level can block the inlet of the catalyst. But I don’t understand why a low material level would cause problems; moreover, I think this reason isn’t sufficient enough. All the other conditions for shutting down the system are meant to protect the equipment and prevent accidents. What you mentioned doesn’t seem to fit this logic that well. Anyway, thank you for your answer!

Is it UOP’s third-generation regeneration? The closed hopper is the core of regeneration, with 3 thermal shutdown conditions: one for long cycle alarm and one for short cycle alarm. It shuts down due to overheating twice in a row. When the buffer level falls below 10%, the feed-to-discharge valve is closed, causing the regeneration cycle to stop. No shutdown due to high material level. A low material level indicates a problem with the continuous circulation; the material is lifted faster at the bottom than it is fed in at the top, resulting in an interrupted circulation. So the cycle of searching for reasons should be stopped.

Sorry, I made a mistake; it’s actually a separate hopper. There are two hot stop interlock conditions. A thermal shutdown below 10% should be understood in this way. The catalyst in the hopper keeps the pressure in the separation hopper higher than that in the regenerator. This is one of the conditions for nitrogen isolation of the catalyst to be prepared. If the material level is empty, the nitrogen bubbles are disrupted, allowing oxygen and hydrogen to mix with each other, which is extremely dangerous. The high level interlock should be understood in this way: a high material level means that the catalyst circulation at the lower part is impaired, which leads to problems with the catalyst flow. In such cases, the operation must be stopped to determine what is causing the impairment in catalyst circulation.

Agree with what was said on floor 8; the main thing is to ensure a proper pressure difference

This post was last edited by che7420 on 2010-8-17 21:59. Rebuttal: There’s no such thing! I’ve never heard of such a theory that a catalyst can maintain pressure. Catalysts have a certain effect of slowing down gas flow, but they cannot prevent it. The pressure in the separation hopper being higher than that in the regenerator is determined by the pressure difference between the secondary gas to be regenerated and the purge gas. The pressure of the purge gas is the pressure at the outlet of the recycle hydrogen compressor minus the corresponding pressure drop; the pressures in the regenerator and the separation zone of the lock hopper are equal. Since the pressure of the purge gas is greater than that of the regenerator and the pressure in the separation hopper is greater than that of the purge gas, it follows that the pressure in the separation hopper is greater than that in the regenerator. The separation hopper continuously repressurizes itself, keeping its pressure slightly higher than that on the front and back sides; these are the nitrogen bubbles. What does it have to do with the material level? Assumption: The separation hopper has no material level; even those few discharge pipes are empty. As long as the pressure is guaranteed, nitrogen can enter the regenerator. The front side can lead into the reactor, and a slight positive pressure does not affect the lifting of the catalyst. As long as a pressure difference is maintained, there is no possibility of cross-contamination. Nitrogen bubbles have nothing to do with the material level. Rebuttal: It’s absurd; please check what the conditions are for entering the quarantine area. Rebuttal: I’m speechless. I came up with a reason and forced it to fit in somehow. How well the catalyst circulation works in the lower section is related to it, with the LHCS handling the logical judgments. Please~~

Interlock is activated when the material level in the separation hopper is low; the purpose of performing a cold shutdown is to prevent high-temperature gases from the regenerator from entering the separation hopper when the material level is low, as this could damage the equipment!

UOP clearly states that operators must understand the pressure control of the regeneration system as well as the gas environment control in its various components; please refer to the general operation manual! Baidu has it