finned tubes repair 1

[fazel1]

we produced some finned tube which are produced by high frequency resistance welding and becaus of the high speed they don't have enough bonding. the thickness of fins is 1mm and the thickness of tube is 2.4mm. which process can we apply to repair these finned tube? (the lengh of tube is 20 meters)

 

[metengr]

fazel1;
There are many different methods for fabricating finned heat exchanger tubing; helically wound, brazing, welding, etc, depending on materials.

As a user of heat exchanger equipment, I would not accept a repair to finned tubing using local brazing or soldering methods – most specifications call for continuous, high-frequency resistance welding to assure maximum heat transfer.

I would scrap the current tube and start over by making the necessary adjustments to your high frequency welding process. This is an effective process for manufacturing finned heat exchanger tubing.

 

[fazel1]

metenger
these finned tubes are so many and if we scrap them it costs very much. we know that efficiency may decrease , but we don't have any other way but repair. so what is the best way to repair them? they are assembled in the harp form and they are not one by one. in each harp we have 3 row and in each row there are 39 finned tube.
thanks alot.

 

[metengr]

fazel1;
I really don't have advice to offer that would help your cause because to repair the finned tubes would require complete removal of the fin and re-application. The bond between the fin and tube OD surface is critical for optimum heat transfer.

Attempting an external repair like solder or brazing short of removing the fin will not yield desirable heat transfer results.

Have you checked with the customer and what they would accept?

 

[fazel1]

metenger
we are costomer ourselves. but because of the time and the amount of problem we have to choose the way for repair and if we choose the repair system we can calculate the efficiency by our softwares. would you please offer me the best way to repair? which type of brazing or soldering is more suitable?