Remedy of double tubular sheets heat exchanger leakage issue

[zhangbd]

Dear All,

Tubular heat exchanger in our plant we use to produce purified and process water(high temperature) for about 5years but, now condensate leakage is visible at the inner tube plate due to the failed sealing off between tube and plate. Because of the special running condition under which the prw(production water) formulation doesn't need continually water supplying, therefore the heat exchanger always stars intermittently and cause shell temperature varying and the expansion stress cause the gaps at the sealing point of inner rube plate and tube bundle.

How to repair this leakage?

Thanks and Reagards

zhangbd

 

[bmoorthy]

The Exact Configuration of the joint is required to give possible temp solution to this problem.

Assuming that the leakage is due to passing of tube to tube sheet joint, one can insert roller expanders and expand the tubes up to 20% thinning of tubes (CS tubes) in the back tube sheet, so that ingress of fluid between the Tube sheets is avoided.

The other option is to Expand the tube beyond the back face of the Back tube sheet. The Hazard here is there is a possibility of cutting the tubes and During Re tubing you may face problem.

 

[zhangbd]

Hi Bmoorthy,

Thanks for your reply, and this HE is a type of double-sheet tubular heat exchanger with tube bundle of 80 pieces, at each end of the tube bundle there are two tube plate. The inner two of the tube plates are used for sealing off the shell, the two outer tube plates together with the collecting chambers make up the rest of the tube bundle. the leakage occured at the jiont of inner plate and tube bundle.You're right of that try to expand the tube against the plate and tighten them again, but this might do the trick. If the roller expander, you mentioned, could do this easily, I prefer this tool could be used by us, instead of other way of cutting and welding.

How to get this roller expander?

zhangbd

 

[deanc]

Be careful! 20% may be excessive. Check with Airetool, Elliott or Thomas Wilson for tools and good practices.

 

[LuizSouza]

Zhangbd,

Concerning roller expanders you can try on

http://www.eliotttool.com.

Have you considered to restoure it by using inserts, you can save up 70% comparing against retubing.