Heat Exchanger ttrip

Do you suspect the gap is the result of corrosion by the acidity of MEG ?
FIT, does it mean flow indicator transmitter ?
Can you describe what are the functions of the reboiler and column ?

No the gap is not due to corrosion as the plates thickness is 12 mm. It's something to do with manufacturing.

FIT is flow indicator transmitter; as you got it truely.

Seperation of MEG and condensate is taking place in MEDIUM PRESSURE SEPARATOR and unstabilised condensate enters the column through an upstream coalescer filter. It goes then to the reboiler; gets heated up and becomes stabilized condansate and leave the reboiler to the cooler. The vapour produced through heating up of condensate goes back to the column and leaves the coloumn from the top as LP fuel gas which is used for flare burners and also purge applications.

Cheers

Can you kindly rephrase your question in regard to the troubles this air-cooler head manufacturing gap is causing, as well as whether the presence of MEG in the "stabilized" condensate is creating any downstream problem ?

25362,

Sorry I missed the question. I did a fair bit of work on this cooler and manufacturer advised to bridge the gap via using "Devcon-Titanium Putty". As I said, theliquid in the condensate cooler is mixture of hot Mono Ethylene Glycol and Condensate (155C). The first question:

1- Is there any concern this putty comes off and ends up in the downstream control valves?
2- In order to apply Putty, what is the devise they use as I believe they have to remove a few plugs and insert this particular devise in there.

Thanks

MEbrahim,

The gap between the vertical partition plate and the tube or plugsheet is apparently due to poor manufacturing techniques. However, I suspect that the 4 mm gap is not the reason for poor performance. If you compare the flow area through this gap to the area through the tubes of each pass, I suspect that the tube flow area is an order of magnitude greater than the area through the gap. Sure, there will be some bypassing, but the pressure drop must be the same through the two flow paths.

You describe the partition plate as "vertical". If the header box is horizontal, and the partition plate is vertical, then the process flow goes down one side of the tube bundle and returns on the other side, and the flow is pure cross-flow with respect to the cooling air. It is as if the bundle were twice as long and single-pass. This can affect the LMTD correction factor, reducing it from a counterflow LMTD. This correction factor is typically about .85 to .90 the value of a counterflow LMTD. This directly affects performance. This is sometime done to accommodate piping, so that the inlet and outlet piping both can face in the same direction.

I would be extremely suspicious of putting some kind of goop inside the header to plug the gap. Will the manufacturer guarantee the result? I doubt it.

Some manufacturers may intentionally underdesign coolers by as much as 20%. Your cooler may be one of those. I have some comments about poor cooler performance at You may find those helpful.

Regards,

Speco