3 replies to this topic

[Anja2111]

Hi,

I´m trying to simulate a stripper column in Aspen Plus with Radfrac. As my column doesn´t consist of a reboiler or a condensor I click "none" each in the radfrac specification sheet. Now the programm wants a feed/pumparound. What can I do to avoid this warnings?

Can anyone help me? Thanks.

[joerd]

Simulation of a process is not about avoiding warnings, but about understanding the process that you are trying to model. If you have a stripper, you are contacting a liquid with a gas, and hope to remove components from the liquid because they will be transferred to the gas.
Therefore, to model your stripper, you need at least a gas stream and a liquid stream. The liquid is fed to the top of the column, the gas to the bottom.
If you don't have a stripping gas, you can use the liquid's own vapor to do the stripping. That vapor is generated at the bottom in a reboiler.
So, in summary, if you provide a feed liquid at the top tray and a stripping gas at the bottom tray, you have a feasible and meaningful process. Otherwise, it doesn't make sense.

[Anja2111]

Hi,
first of all,thanks for the quick reyplay.
About the process. I do understand what the Stripping is about and in my problem I have a liquid stream at the top of the column and a gas feed at the bottom. But still the Program asks for a pumparound. So do you know anything that could help?

Check in the column specs the streams!
When u are using either a condensor or reboiler you must specify the streams as "on stage"