4 replies to this topic

Hello,
I'm trying to rate an exhisting packed splitter regarding its load capacity, flooding point, etc, i.e. its limitations.
But I'm not undestanding the meaning of Aspen results such as maximum fractional capacity and maximum capacity factor and how to use them for comparison between different operation points.
Thanx in advance for helping.

[Steven_Zhu]

Hello,
I'm trying to rate an exhisting packed splitter regarding its load capacity, flooding point, etc, i.e. its limitations.
But I'm not undestanding the meaning of Aspen results such as maximum fractional capacity and maximum capacity factor and how to use them for comparison between different operation points.
Thanx in advance for helping.

Please make sure which software you using, such as Aspen Plus, Aspen HYSYS, it may be helpful.

Best wish

Aspen Plus.

[Andrei]

Steven,

Your question was not necessary, the only Aspentech simulator that supports packed towers is Aspen Plus, Hysys is not supporting them, never supported them and there is no future plan to support them.

Rafael,

I have in front of me Aspen Plus Help opened. There is a nice explanation of the capacity factor there, and a calculation formula. It is under "Packings, capacity calculations". Maximum fractional capacity is the fractional approach to the maximum capacity, it is explained on the same page. I am no Aspen Plus expert but I am sure that the documentation explains even better the concepts.
In some of the programs when you drive the mouse arrow over the Help button a yellow pop-up appears, saying "This really helps". I strongly recommend to use that button.

[Zauberberg]

For Aspen HYSYS, if there is "Tray sizing" utility available within the utilities list, packed towers can be rated as well. Several types of structured and random packings are listed, but I'm not sure about the accuracy of HETP and various correlations. This should be checked with the manufacturing vendors.