horizontal double wall pressure vessel 5

[Pedro Losino]

Good morning, I am starting the design of a double-walled horizontal pressure vessel to store ethylene. For temperature reasons, to avoid boiling of the ethylene, a double-walled container is proposed, with a vacuum in the annular space to act as an insulator. The design code needs to be ASME 8. Studying the code has raised doubts about the design process to follow. I understand that the internal container is designed by internal pressure, and the external container by external pressure, contemplating in the latter case a design pressure a little higher than atmospheric.
I appreciate any opinion on this, thank you!

 

[MJCronin]

Hello ...

I agree with all of the comments above, especially the one that says this is a packaged specialty item and best fabricated by an experienced pro ...

https://www.bewellcn.com/product/liquid-ethylene-storage-tank/

https://www.linde-engineering.com/en/images/P_3_3_e_12_150dpi_tcm19-5774.pdf

I do not understand your statement "The equipment is designed and manufactured because I am from Argentina and there are no possibilities of buying it abroad"

Can you tell us more ? ....

MJCronin
Sr. Process Engineer

 

[kremenco]

Our company design and manufacture these type of horizonal ethylene cryogenic storage tanks. We have supplied many such tanks to our US clients.
What GBTorpenhow and jt1234 described is correct. To add to that, the inner vessel is supported on the outer vessel at the saddle locatios by using epoxy tubes (to minimize heat transfer)
@Pedro Losino, as someone described above, the design is of specialized nature and experience counts. You cannot do it on your own if your company is not experienced in this field.
Regards,

 

[LittleInch]

kremenco,

What design pressure do you use for the outer shell? 0barg (atmospheric) or something higher?
What do you use for overpressure relief on the outer shell - a bursting disc?

How are the nozzle connections done to avoid excessive cold break / connection from inner to outer tank?

I think these are the details the OP will struggle with so you many not want to answer, but if you could would be good to know.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[kremenco]

Hi LittleInch,
Happy to answer those questions.
Outer Vessel Design Pressure: 15 psi(g) external, 0 psi(g) internal.
Inner Vessel Calculation Pressure: Internal design pressure + 15 psi(g) to account for the external vacuum.
Safety heades are provided on outer vessel sized according to CGA 341
Stainless steel pantlegs are provided on nozzles at outer vessel exits.
Hope this helps.
Regards,

 

[LittleInch]

Pantlegs??

I'm guessing these are essentially outer pipes welded to both shells or maybe just the pipe with insulation.

But thanks for response. It seems that 341 is used for any size of vessel not just road tankers.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[kremenco]

Pantlegs are like sleeve pipes welded to the outer shell. One end of it is closed with a flat plate or cone through which the annular space piping connected to inner vessel nozzle comes out.