Commissioning and adjustment of the catalytic unit

It should be turned on when changing from external tower circulation to internal tower circulation； After changing from external circulation to internal circulation in the tower, the valve on the tower wall opens, so there is no longer any risk even if diesel or gasoline enters the tower. It will be too late to open it once the temperature reaches a certain level after feeding begins.

If the internal circulation of the tower is activated, the extraction valve will open, and won’t a lot of water enter the system? Will it then be necessary to remove a large amount of water as well?

This is necessary. Especially at the pump and several low-point vent locations downstream of it.

Both valves are located on the platform; they are usually opened early to save time. If there are enough personnel, they can also be opened after feeding begins.

Open before feeding; dehydration must be carried out promptly.

When the fractionation system is started, when should the middle and top recycle extraction valves be opened? (Should it be turned on during internal circulation of the tower, or after feeding when the temperature reaches a certain level?) What is the reason? In my opinion, the top circulation can be activated when an internal circulation is established ； However, it is best to wait until a certain temperature is reached after feeding into Unit 1 before opening the extraction valve, in order to prevent light oil from flowing into the inlet of Unit 1’s pump; otherwise, it will vaporize as the temperature rises, resulting in the pump not being able to deliver fluid. Regarding the water cutting operation mentioned by everyone, it has been carried out continuously during external circulation in Unit 1 and the top circulation tower. Personal opinion, thanks for the feedback

We have started up our unit several times, and the procedure is always the same: after removing the oil and gas blind flanges, the distillation is changed to internal tower circulation, and once this circulation is operating properly； Open each valve sequentially from the top of the tower to the bottom ； Secondly, since the overhead circulation and diesel systems are filled with gasoline and diesel, when they are opened, a large amount of steam from the reaction system will condense at various extraction points depending on temperature changes. It is necessary to carry out proper water removal at designated locations and maintain close supervision to prevent oil leakage ； Third, control the temperature at the top of the tower properly to prevent excessive temperatures from causing the product at the top of the tower to become unsuitable for use, thus preventing it from entering the reflux tank at the top of the tower ； Polluted products, extended operating hours ； Personal opinion!