Stacked Shell & Tube Heat Exchangers 2

[andrewleong]

Hi all,

I have a query regarding stacked shell & tube heat exchangers.

I have 2 nos shell & tube heat exchanger for different services (with different design conditions) with below details:

exchanger 1 : 1200 (ID) x 6300 (tube length)
exchanger 2 : 1050 (ID) x 6000 (tube length)

since they are located near to each other, piping & layout is asking if possible to stacked together mechanical wise. From a quick sketch, the height would be around 6m.

Mechanical wise, i do not favor stacking as i see that it will pose difficulties and troublesome during detail design stage considering that they are for different services and many design loads/ requirements to considered (cyclonic wind, FPSO vessel motion, blast load etc).

Could anyone advise what are the concerns for such stacking arrangement?

Many thanks

 

[andrewleong]

Forgot to mention they are U tube type exchangers which require bundle removal during maintenance.

 

[TD2K]

I've seen different service exchangers stacked usually in locations where plot space is at a premium. As far as getting access to the top exchanger for pulling the U-tube, that's an issue whether the services are the same or different and should be addressed in your project specifications/discussions with the client. I've seen some exchangers located pretty high in the air that the client apparently had no problems pulling the bundles when they needed to clean them but that was on land, not a FPSO.

 

[gr2vessels]

Obviously, stacking any exchanger raises technical problems to overcome, but not impossible. They don't have to be the same service and is your technical ingenuity to resolve different expansion issues, including arrangement of saddles for stacking. If that will create too many problems, stick them like bunk beds on a vertical supporting structure, without actually stacking them in top of each other. You are the only one to evaluate the benefit of stacking them high, against the disadvantages created be additional loads, maintenance requirements, access and piping modifications.
Cheers,
gr2vessels

 

[andrewleong]

Thanks for the reply.
I have another heat exchanger which i did not mention in earlier post as below exchnager 3:

exchanger 1 : 1200 (ID) x 6300 (tube length)
exchanger 2 : 1050 (ID) x 6000 (tube length)
exchanger 3 : 1200 (ID) x 5700 (tube length)

I need to choose 2 of them to be stacked and considering whether to stack the 2 exchangers with similar ID or similar length.

similar ID : exchanger 1 & 3
similar length : exchanger 1 & 2

Anyone could give an idea which option would be more suitable and pose less issue for design and fabrication?

Thanks again.

 

[SnTMan]

I'd stack (2) on top of (1) if I could, or second choice, (3) on top of (1). I'd prefer that (2) not be the bottom, but with proper support design, it could be. They could all three be stacked. Depends more on you plant real estate than the exchangers themsleves.

Regards,

Mike

 

[vpl]

Mike (SnTMan), that does seem kind of obvious doesn't it, given the dimensions. The choice of which to choose would seem to be somewhat dictated by the physical layout. I wonder if nickkcy85 has wandered down into the plant yet and measured the space where these heat exchangers need to go and the room available for removing the internals?

I've seen a fair number of stacked heat exchangers over the years and don't really see what the big deal is.

Patricia Lougheed

******

Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of the Eng-Tips Forums.

 

[SnTMan]

vpl, yeah, since they apparently don't interconnect...

 

[SnTMan]

(BTW, I often notice the obvious

 

[Duwe6]

With stacking, one monorail centered over the shells, will allow easy removal of any of the tube bundles. That's one reason that 'real' Plant Engineers stack dissimilar Hx's, along with cascading banks of Hx's.