Tube buckiling in Shell & tube HX (UHX13 & TEMA 7-24)

[Peregrino7]

In the mechanical design of Shell & Tube Heat Exchangers with fixed tubesheets, there is a problem with tube buckling, when calculations are made for the fixed tube sheet design. (ASME - UHX.13.5.9 and TEMA RCB-7.24).
How can I avoid this problem? I have tried to decrease the unsupported span length but with no success, and expansion joint is not allowed for this equipment.
Best regards,


G

 

[Christine74]

You can also try using tubes with a heavier wall thickness, larger diameter tubes, tubes made from a material with a higher modulus of elasticity, or tubes made from a material with a lower coefficient of thermal expansion.

-Christine

 

[StoneCold]

This is why many heat exchangers are of the U-tube design.

StoneCold.

 

[Peregrino7]

But there is a temperature cross, so two tube-pass is not possible. Thiker tubes is possible, and it may improove the problem, but it is expensive to put SS tubes BWG-12...!!
Thanks for your comments...!


GH

 

[Montemayor]

Peregrino7:

There are various alternate solutions to your dilemma. However, like most queries, you don't furnish any basic data or scope - fluid ID, pressures, temperatures, restricted to Shell & Tube design, etc. Without any of this data, any response is subject to your rejection or opposition. This thread will extend for days without any useful information or resolution being reached.

I could suggest (if you have to use a 1-pass, shell & tube) that you employ a TEMA BEP, BES, or BET but you might not like them. I could also recommend a spiral; but you might reject this also. Without specifics on the application and any restrictions imposed, it is difficult (or frustrating) trying to contribute useful or helpful information.

As Stonecold infers, a U-tube would resolve the situation. A U-tube unit is not restricted to only 2-passes. You can have multiple passes in a U-tube unit. But is this allowable?