Dual Pressure Chamber Vessel

[cwood3]

I'm trying to figure out to do this:

I have a vessel that is a still column/reflux accumulator. Let's say 16" O.D.

The still column is a simple cylinder with an ellipsoidal head on each end.

The reflux accumulator is a cylinder with an ellipsoidal head on the bottom, and the top end of the cylinder is welded to the bottom head of the still column, thus making one tower.

Will COMPRESS allow me to attach the lower cylinder directly to the bottom head of the still column, or do I have to treat each as a separate vessel.

They both have the same design conditions of 50 psig @ 300F.

Thanks.

 

[cwood3]

"Internal Head"........duh...........nevermind

 

[hamburg113]

Hi

This topic help me a lot in developing my project. I will contribute more when I finished it.

 

[jharris3]

I designed a 5.5' double PV tower that replaced a burnt down triple PV tower.

I used compress and yes use "internal head". Additionally calculate the required size of the welds involved with the joint and choose an appropriate joint configuration from the VIII Div 1 UW-13. The design pressure for the head will not be simply 50 psi internal pressure but rather the maximum differential pressure between the two chambers.

So if there is a vacuum pressure for either of the vessels then add that to 50 psi as an external pressure on the head.

when I designed the double vessel the end result was that I had ~80 psi on the concave side PV then the other PV was about 70 psi MAWP but I had to add 15 psi of vacuum to it because the first vessel could be empty while the second was in operation.

Then add CA requirements of both vessels to the thickness of the head.