disadvantage of using copper tubing over SS tubing for gas sample cooler

[bansalh]

Dear All,

For a gas sample cooler what are the disadvantages of using copper coil over SS coil apart from cost factor

Operating parameters are:

Gas - 55% H2, 12% CH4, CO 13%, CO2 11%

Temperature 750 Deg C

Pressure - 35 KG/Cm2

Cooling media - Water(Silica - 1PPM)

 

[racookpe1978]

That particular "gas stream" appears low corrosive ... Unless it ever gets wet, or has any water vapor contamination or any chance of sulfer and water vapor. Then, corrosion problems and mitigation (thicker walls, stainless steel has to be used, wall contamination and deposits and sludge/munge/corrosion residue) will dominate the heat transfer benefits of copper.

Too bad you can't use silver. 8<)

 

[TD2K]

That's pretty hot.

Have you looked at the physical properties of copper at that temperature? I remember one job when the client wanted to use copper tubing for steam tracing and my mechanical people wouldn't sign off on it and it was a lot lower P and T that what you have.

 

[MJCronin]

TD2K is correct.... TOO HOT !!!

Your 750C is far, far above the ASME B31.1 limitations for copper pipe....

Go with 316 SS tube !!

MJCronin
Sr. Process Engineer

 

[georgeverghese]

Even with austenitic SS, check for risk of chloride SCC if you have traces of water vapor and chlorides. If you do, some higher grade duplex SS may be required.

Also check cooling water side skin temp is less than boiling point at 35kg/cm2, unless this CW is of BFW quality.