Will a failure of the main fan, which stops air supply, cause the catalyst in the regenerator to be lost?
Thread Content
This post was last edited by B0SS on 2017-7-7 18:15. I’m a newcomer; I’m seeking advice from the more experienced users. Is there anything wrong with the accident report below? A fault occurred in the comprehensive protection system for the motor of the lubricating oil pump of Fan 2# in the catalytic unit; the motor’s comprehensive protector triggered abnormally and caused a power shutdown. As a result, the lubricating oil pump of Fan 2# stopped operating, and the pressure in the main lubricating oil pipeline dropped too low. This triggered the interlock mechanism related to low lubricating oil pressure in Fan 2#, which in turn caused the overall interlock system of the unit to activate. This led to fluctuations in the operation of the regenerator in the catalytic cracking unit, catalyst loss, as well as issues such as the need to vent excess gas from the downstream distillation system. The dense-phase inventory in the regenerator is 126 tons; after losses, the inventory drops to 70 tons, resulting in a loss of 56 tons. (The fault was resolved after two hours; is it possible to experience such a high level of catalyst loss?) In my opinion, simply put, it was a failure of the main fan, which caused an interruption in the air supply to the regenerator, thereby leading to the loss of catalyst inside the regenerator. Is this logical?
Without the main air flow, there’s no way for the gas to escape; if the main air is gone, then the smoke is gone as well – where can it go? As for leakage, it can be described as leakage due to significant pressure fluctuations in the two vessels during the process of restoring main air supply.
It’s normal for leakage to occur when the main air flow fluctuates. Because after the main air supply is interrupted, if it are two regenerators, the catalysts will fall out. The material legs and seals will no longer be available; when trying to restore the main airflow, there will be significant losses first before it’s possible to seal the material legs. Additionally, injecting combustion oil after restoring the main air flow can also cause leakage. When the flow in the two reactors is interrupted, the reaction will also suffer from material loss.
“ The dense-phase inventory in the regenerator is 126 tons; after losses, the inventory drops to 70 tons, resulting in a loss of 56 tons. ”Is it referring to the situation after the main fan stopped? If so, the stored amount at that time would no longer be accurate.
At this point, it’s mainly about looking at the trend – at least the reserves are on the decline! The fact of the runaway was not caused directly by the shutdown of the main fan, but rather by the operational fluctuations resulting from that shutdown!
After the main fan returns to normal, directing the main air flow toward the regenerator can cause catalyst loss; the situation you mentioned is also possible
So how can we accurately determine exactly how much has been used? Do I need to go to the DCS system to check it?
Most devices have a screen showing the total storage amount; if not, the trends of various storage amounts can be displayed and compared to determine it!