Coker main Fractionator Design

[viditraj]

There are two types of design for the main fractionator of Coker.
1. the side stripper vapors enter the stage Above the pumparound return stage.
2. the side stripper vapors enter the stage Below the pumparound return stage.

What is the difference in the two and when to use which layout?

[Pericle]

It is use because you want to improve the cut between the light and the heavy gasoil.
I don't have experience in the Coker unit but i think that it also depend about the quality of the feed, normally if you have a heavy feed you should use the case no. 2 that you are talking...

This is my point of view.

Regards

[mobek]

Normally the feed is introduced at the tray where the compositions matches. So, when you see the feed enters above the P/A it means the feed composition matches the composition at that tray. This is a rule of thumb in selecting feed point.