Bulging and bluging of heat exchanger tubes

[engtalal]

Due to overhual of exchanger we found that, hard scale inside tubes and most the tubes are blugged and have Bulging.

we tried to clean it by 10000 psi water jet but still the tubes are blugged and difficult to clean it.

Therefor, we can't use eddy current test(to check on tube thickness and their intgrities) due to blugging

The design pressure of the tube is 7.0 kg/cm2.
fluid is sea water
Design temp. is 60 C
operating temp. is 39.6
opertaing pressureis 1 kg/cm2
Tube material is copper nickel( C7060T )

Are there any method of cleaning or temperary & permenant solution?

Note:
it can't be cleaned by chemical, because that may lead to tube corrosion

 

[metengr]

Bulging of any heat exchanger tubing is a serious concern, and will not be effective for water blast cleaning. To remove the scale on the ID surface of the tubing, you need to consider an inhibited acid solution or citric acid to dissolve the deposits. Citric acid is typically preferred on copper heat exchanger tubing that is in service. You can also evaluate an inhibited hydrochloric acid solution.

This heat exchanger sounds like it needs to be re-tubed.

 

[eyec]

agree with metengr on re-tubing. a short term solution could be to "shoot" the tubes with abrasive balls.

 

[EdStainless]

Bulging of the tubes indicates some serious mechanical problems with the heat exchanger.
Did they plug and then bulge? What are they pluged with? If it is scale you will need to acid cleaned. The unit sounds like there is no hope of salvage anyway. Start planing the re-build.

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Corrosion never sleeps, but it can be managed.

http://www.trenttube.com/Trent/tech_form.htm

 

[unclesyd]

If the tubes are plugged there is nothing short of mechanical drilling or hyper blasting (greater than 13,500 psi) will salvage the tubes.

Either method requires someone with experience in the methods mention to preform the service. Neither is job for amateurs. I would contact someone in your area that has the equipment and experience to look at the job.

At your operating pressure I don't believe a bulged tube/tubes are detrimental other a place for scale to start forming.