Shell & Tube Heat Exchanger Baffle Seals

[Morts81]

Gday Forum Members

My question is a simple one today (or so I hope). I'm familiar with longitudinal baffle seals (ie, kempchen, etc) for Shell and Tube Heat Exchangers, however, I'm not familiar with any transverse baffle sealing systems.

We need something for a couple of baffles and they need to allow the tube bundle to be removed (whether the seals are re-usable or need replacing is not of my concern).

Appreciate any responses or recommendations.

Cheers

 

[gr2vessels]

There is no seal on traverse baffle, but gap between baffle and shell ID, refer RCB-4.3.
Cheers,
gr2vessels

 

[georgeverghese]

For these seal strips used to minimise shortcuiting of the tube bundle (and hence increase shellside htc), shell and tube HX manufacturers should be able to help ?

Guess you are in a tough spot having to consider these in a debottlenecking options study ? - okay. Some oil companies do not recommend installing these for new projects, since seal strips can get damaged during tube bundle removal.

 

[Morts81]

Thanks for the responses so far guys

gr2vessels, I understand the spacing between transverse baffles and shell ID as per the TEMA code which allows a certain amount of bypassing, however, in our case we have a somewhat non-standard exchanger where we need to ensure there is zero (or as close to possible) bypass across a couple of baffles.

georgeverghese, yes, in a bit of a tough spot unfortunately, the issue is because we have to have a demister pad installed in the exchanger shell (velocities are too high to have one in outlet nozzle) so we have to ensure that we don't bypass around some of the baffles. It's quite a unique design.

 

[SnTMan]

Morts81, philosophically, no problem, more of a fab problem.

Depending on the service and bundle weight you could:

Use a silicon rubber extrusion. Various profiles are available.

Use a braided packing.

Fabricate a metallic or rubber leaf seal, similar to a long baffle seal.

In each case the problem, as I see it, revolves around manufacturing capabilities, dimensioning / tolerancing and maintenance considerations.

For an extrusion or leaf seal, damage could occur during bundle insertion / removal. Clearance between cross baffle and shell would need to be such that the seal could reverse itself during insertion / removal, as such the clearance might be greater than TEMA.

Need room around the tubefield to attach any such seal, bolting bars and so forth.

Seems to me that packing might be the best choice as it would not presumably need to reverse during insertion / removal. You'd fab a sort of a partial circular kind of inverse gland to pinch the packing to the cross baffle.

Regards, and lotsa luck,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[Morts81]

Thanks SnTMan, this is most helpful.

 

[SnTMan]

Morts81, I have discussed the "Baf-O-Seal" with co-workers in the past. If you go this route, please let us know what you did, if able to share it.

Regards,

Mike

The problem with sloppy work is that the supply FAR EXCEEDS the demand