Analysis of the reasons for sudden agent leakage in the regenerator?
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The unit is a 500,000 tons/year heavy catalyst regenerator; the diameter at the bottom of the regenerator is 5.8 m, while that in the dilute phase is 7.2 m. The total capacity of the regenerator is 95 t, with the dense phase having a capacity of 78 t. The main air flow rate is 68,000 Nm3/h, the pressure in the regenerator is 235 KPa, and the pressure difference between the two phases is 35–38 KPa. With production remaining stable, sudden leakage occurred; the main air flow dropped to 53,000 Nm3/h. The total inventory level stayed stable for 5–6 minutes before leakage continued. When the total inventory in the regenerator fell to 45 tons, it was necessary to stop feeding material in order to prevent further issues. Subsequently, following the startup procedure, neither single-unit fluidization nor two-unit fluidization resulted in any leakage of the fluid. I would like to ask the experts: 1. What level should be set as the optimal total reserve for the regenerator? 2. What are the main reasons why the flap valve cannot be opened? 3. How should such leakage phenomena be avoided? Thank you to the expert for the answer!
The density at the inlet of our regenerator centrifuge is between 9–12 kg/m3, and the centrifugal pressure drop is 6–6.5 KPa. What is an appropriate value for these parameters?
The pressure drop in the centrifuge is 6–6.5 KPa; I think that’s quite low, right? Does it fluctuate a lot? The catalyst loss might be caused by inflexible wing valves. How old are those wing valves? Is their condition checked during maintenance? Our unit has a capacity of 500,000 tons; the diameter at the bottom of the regenerator is 5.8 m, the diameter in the dilute phase is 7.2 m, and the height of the dense phase bed is 8.5 m. The pressure in the regenerator is 0.195. The total amount of catalyst stored there is usually around 75 Tons; when it exceeds 80 Tons, the catalyst needs to be removed. We’ve experienced an incident where a large amount of catalyst was lost. Keep an eye on whether there’s a sudden decrease in the centrifuge’s pressure drop. Be aware that the indicated amount of catalyst stored might not be accurate; reduce the amount of catalyst stored in the regenerator accordingly. Conduct catalyst analysis. If catalyst loss occurs, reduce the main air flow and increase the pressure in the regenerator. Hehe, I’m not an expert – just a beginner... But I hope this can be of some help
1. Was a replenishment started after the agent was run out? If it wasn’t replenished, then it’s fake. 2. If there was indeed leakage, what were the pressure drops in the distribution pipes, the density of the regenerator, and the pressure drops in the cyclone at that time? My unit has a similar air flow rate to yours, with pressure drops around 8 kPa. 3. With such severe leakage as you described, it’s impossible for everything to return to normal just by stopping the feed and restarting the operation