Vapor belt (distribution cylinder) vs Jacket Vessel

[OscarAb]

I have been having a debate with a colleague, in regards to the design of a distribution cylinder (vapor belt) on a shell and tube heat exchanger.

Several thoughts on this are:
1. Mandatory Appendix 9: Jacketed Vessels
a. Historically, this is the method that has been used in the fabrication industry however this method does not address the opening in the shell.
2. Mandatory Appendix 14: Integral Flat Head with a large, single, circular centrally located opening, using UW-13 attachment.
3. Mandatory Appendix 5: Flanged and Flued or Flanged only Expansion Joints.
a. This could be an option for fixed tubesheets exchangers such as a TEMA style NEN or similar configuration.

Which options have been accepted by your shop authorised inspector or your discussion with the A.I. to support your method.

What are the communities’ thoughts?


Thanks,

Trevor

 

[innovation2]

The use of App. 9 jacketed vessels is used if the shell continues inside the plenum. You can cut holes/openinings inside the plenum section as long as they are not across the circ. of the cylinder. Typically 3 holes of equal size to vapor inlet are used. If there is a break in the shell then the plenum closures have to be designed in accordance with App. 5 and tubesheet has to account for the reduction in spring rate.

 

[STguy]

Hi I partially agree with you innovation2, however as an AI asked, what is the intent of Appendix 9, jacketed vessel? Appendix 9, paragraph (d) indicates:
(1) to heat the vessel and its contents
(2) to cool the vessel and its contents
(3) to provide a "sealed insulation chamber" for the vessel.

But also indicates such as.....

None of the above apply to a distribution cylinder as it has a break in the closure.

Also, paragraph (c) also talks about the vessel and the jacket as if they where seperate chambers and also limits the pressure to 15psi or less on the inner vessel wall. Which would work if your design pressure is below 15psi, however if your shell side design pressure is greater than Appendix 9 would not apply.

STguy

 

[STguy]

Hi I partially agree with you innovation2, however as an AI asked, what is the intent of Appendix 9, jacketed vessel? Appendix 9, paragraph (d) indicates:
(1) to heat the vessel and its contents
(2) to cool the vessel and its contents
(3) to provide a "sealed insulation chamber" for the vessel.

But also indicates such as.....

None of the above apply to a distribution cylinder as it has a break in the closure.

Also, paragraph (c) also talks about the vessel and the jacket as if they where seperate chambers and also limits the pressure to 15psi or less on the inner vessel wall. Which would work if your design pressure is below 15psi, however if your shell side design pressure is greater than Appendix 9 would not apply.

STguy

 

[OscarAb]

Innovation2,

In Appendix 9, figure 9-5(b-3), dimension tc (nominal thickness of closure memeber) and trc (required thickness of closure memeber), in which the formula is found in Appendix 9 paragraph 9-5(c)(2). Do you considered the additional reinforcement required for the large opening in the flat head?

 

[innovation2]

See section UHX-4(d)

Best regards