Can this be done after cutting the catalyst device?
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Coaxial design, external lift pipe, single reactor with single stage oxygen-deficient incomplete regeneration. After the feed is cut off, both reactors are shut down; the regenerator operates in a bed-muffled mode, while the settler maintains single-container fluidization. When the settler operates in single-vessel fluidization mode, the reaction temperature drops rapidly. Although the steam supply to the lift pipe and the settler is increased promptly to displace the oil and gas, high-boiling-point, large-molecule oil and gas are more likely to cool and condense into coke, thereby exacerbating the formation of coke deposits in those areas. Regarding the operations after cutting the material above: Is the method of \"operating the regenerator with a packed bed and keeping the settler in single-container fluidization\" correct?
It’s probably done for security reasons! In your actual operations, do you simply find that coking occurs easily?
As a supplementary note: This phenomenon occurs during operations where power is out for 6 to 13 hours, and the device temporarily stops feeding. I’m not sure whether performing cutting operations during power outages within such a time frame is normal; does anyone’s equipment operate in this way?
If we stop for as long as you say, the only option is to perform bed holding operations; otherwise, the catalyst will suffer excessive wear!
After the catalytic feed is cut off, the regenerator becomes clogged; a large amount of steam is introduced into the settler and the lift pipe, with the aim of keeping the pressure in the settler higher than that in the regenerator, thereby preventing air from the regenerator from entering the settler and causing it to catch fire.
There’s no need to cover the bed for a short period of time, right? With both units in a fluidized state, keeping the pressure in the settler slightly higher than that in the regenerator and ensuring proper level control, the oil and gas from the settler will also be directed into the distillation tower, so no problems will arise.
If the cutting time is not too long, try to avoid clogging the regenerator as much as possible. Maintain fluidization in the three reactors, keep the pressure in the settler higher than that in the regenerator, and ensure that the temperature at the outlet of the riser is not too high.
If the main air supply is not interrupted and only the feed is cut off, there is no need to stall the bed; for catalysis, stalling the bed is generally not advisable. Cut off the feed and set the differential pressure; fluidize with a single reactor.
This post was last edited by fdfcc on 2009-5-14 at 19:12. The operation of sealing the regenerator bed, with the settler maintaining single-container fluidization – in my opinion, this method is not feasible. I have experienced the operation of sealing the regenerator bed; by controlling the differential pressure, closing certain valves, stopping the main air supply, and closing the primary and secondary air valves, it is possible to maintain the bed temperature without the need to inject combustion oil over a long period of time. After cutting the material, steam is used to purge the oil and gas in the lift pipe settler; the regeneration valve is closed to transfer the unregenerated catalyst to the regenerator, and the unregeneration valve is also closed. Since the regenerator has a bed that is not fluidized, there is no need for the settler to maintain fluidization; fluidization in the settler is therefore meaningless at this point. The stripping section can maintain a certain reserve to prevent high reaction pressure from forcing the oil and gas into the regenerator. However, after the temperature of the settler drops, due to the influence of steam quality, it may be difficult to fluidize the catalyst again.
I’d like to discuss this with the person upstairs: \"It’s possible to maintain the bed temperature without using burning oil after keeping the bed sealed for a long time.\" In my opinion, after sealing the bed, it’s not that burning oil can be avoided, but rather that it must not be used at all; moreover, the agent should be removed immediately once the temperature drops to 400. “In the case of a clogged regenerator, there is no issue of the settler maintaining fluidization; in my opinion, it is necessary to introduce a large amount of atomized steam and stripping steam to ensure that the oil and gas in the settler are carried away. Since water vapor can be condensed in the cooler at the rear, this also prevents pressure buildup within the reactor. Additionally, this approach helps to prevent oil and gas from coking inside the settler. Please point out any mistakes!
There is no wind; it’s not possible to inject burning oil. The regenerator has a bed that’s blocked, so how can the settler remain fluidized?