separation processes

[Fahad11]

Greetings,

In regards to distillation and separation processes such as fractionation towers and splitters, there are some columns with two different section diameters such as Propanizer which the lower section has larger diameter than the upper one. So, what is the main reason for a such design ?

Appreciate your inputs

Regards,

 

[EmmanuelTop]

Section diameter is determined purely by vapor and liquid loads in the corresponding section of the column, for given type of column internals.

Due to feed conditions (composition, temperature) and specific product quality requirements (purity of C3 on top, and amount of C4+ in bottoms), it can occur that the section above the feed tray takes significantly less vapor or liquid load than the section below the feed tray, and the result of that is a smaller section diameter above the feed tray.



Dejan IVANOVIC
Process Engineer, MSChE

 

[georgeverghese]

To add to ET's reply, you may also see that the column dia increases immediately above the main feed tray on this depropaniser.

 

[Fahad11]

Thanks gentlemen for your prompt responses.