Questions regarding the initial commissioning of the device?
Thread Content
During the initial startup of the unit, for a distillation tower, it is necessary during the steam purging process to disconnect the associated air coolers and heat exchangers, purge the pipelines thoroughly before reconnecting them to the equipment, or directly introduce the steam into the equipment and vent it at the reflux tank or flanges. If the standard procedures are followed, it increases the workload related to securing the connections, and it also raises the possibility of more leakage points – after all, those flanges need to be undone and then tightened again. This, of course, hinders progress in starting up the process. Let’s discuss together: under the premise of safe operation, how did you carry out the initial startup steps?
Disconnect all purging systems before connecting to the equipment, and connect it only after it has passed the inspection. There’s also an airtight seal, so there’s no risk of leakage.
The flanges connecting the process pipelines to the equipment must be detached, cleaned thoroughly, and then reconnected
I wonder how other devices are purged? When we first started up the plant, we didn’t perform individual purging of each piece of equipment; instead, we only disconnected it at the reactor inlet and carried out several burst purges, purging even the furnace tubes as well.
Is practical operation similar to theory? ? The procedures are too complicated; following them all to the letter will inevitably slow down progress. On the other hand, if problems arise due to not following the procedures, no one can take responsibility for that. . How do you proceed in practice? I learned before that in some cases with air cooling, it’s done right away; for systems that make extensive use of air cooling, if the disassembly is done at the inlet, the workload is quite substantial. . .
That’s the best approach, and it’s also what the regulations require. So, how much can there be of a discrepancy between actual practice and the regulations? ?
We also encounter this situation: many practical operations do not follow the procedures
The diameter of the vapor line at the top of the tower is usually too large. It’s best to install manual valves on each branch before the air cooling section; cleaning can be done more effectively by removing the flanges and using pressure to blow out any residues. When we started operations, due to lack of appropriate facilities, we simply used air for cleaning. At the beginning of operations, there were serious problems with the level gauges in the reflux tank. It was very easy to remove and reattach the low-pressure flanges. When it comes to cleaning, the key is to ensure thorough cleaning. Of course, if conditions permit, it’s advisable to check each seal, including the flanges and gaskets, before sealing them again, so that the airtightness is guaranteed from the start.
Steam is supplied at the inflation point; the entire system is connected in series, with steam being vented from the reflux tank, and steam is also present in the liquid discharged from the bottom of the tower. After steaming the tower for a period of time, turn off the steam and introduce nitrogen to maintain a positive pressure in the system. The oxygen level is fine after just one check.