Unusual Jacket Design on Head

[waskillywabbit]

2:1 Elliptical Head at 75/FV psi 350 F

Customer wants a "conventional" jacket on the head w/ an internal spiral baffle. They want a 6" spacing in between spirals. Jacket at 150/FV psi 350 F which seems to make the thickness of the head enormous (like 5 times) compared to the unjacketed top head and the shell thickness. I'm at a bit of a loss how to proceed...

...on how to get it all welded together w/ proper fitment and/or how to design such a baffle to minimize blow by so as to make the jacket effective. Why not just use a half pipe?

They are using a 3" half-pipe jacket on the shell, but don't understand why they want such a jacket on the head.

Any ideas?

Brian

 

[SnTMan]

Brian

Can't guess WHY, but:

Have done a similar job sometime back. The external (jacket) pressure will make your "inside head" thicker, more so than you might expect.

As to the spiral, it sounds like the jacket process enters near the head center, and exits near the skirt or vice-versa. Spiral can be roughly formed of thin material, in pieces if necessary, and welded to either head before assembly. It will take some fitting to get a close fit to the other head, but it can be done.

If this is Sec. VIII, Div. 1, Appendix 9 gives design rules.

Good luck