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I am looking for a heat exchanger specialist or a manufacturing company who would be able to help with tube bundle failures which are very regularly occurring on a horizontal thermosyphon reboiler on a sour water stripper.
We are suspecting a mechanical problem like vibration or something else. The tubes are failing in six month to a year even if they are upgraded to stainless steel.
The problem does not seem to be related to corrosion from the process fluid.
 
Answers
18/02/2008 A: Mike Watson, Tube Tech International Ltd, mike.watson@tubetech.com
We come across this quite a lot as a hi tech cleaning contractor.
9/10 times erosion caused by vibration is the cause during process.
The tolerance between tube support plates and tube may be too great.
Possibly a non uniform deposition layer within or outside the tube builds up and subsequently creates preferential flow, creating a localised frequency of flow that creates this unwelcome oscillation.
Process of elimination really i.e. we would clean it back to bare polished metal after inspecting with a video probe (for visual evidence) then eddy current or iris / mfl to establish locality and severity of wall loss over a given time period.
15/02/2008 A: KengYong Chan, Air Products & Chemicals, Inc, chanky@apci.com
I did have similiar experience, with my previous company, on a stab-in reboiler of column that has a steam sparger below the reboiler. We had pulled the bundle out on many occasions due to tube rupture/failure and the failure mechanism was tube erosion/shearing due to vibration. We managed to solve the problem with a combination of steam sparge re-design and addition of reinforcing rings after several trials.
Not sure the exchanger design and the setup inside the stripper column is identical or similar to my experience. You can email me to discuss further.