Material use for pressure vessel in supercritical water 2

[cktayum]

I am designing a reactor,which need to hold up to 600C and 250 bar, any idea what material should I use?

 

[GenB]

I do not know what to say but if you do not know the MATERIALS to build this hi-press and temp you are in a lot of trouble and need real help and not ideas from a forum.
Please look at ASME B&PV Code Sec I (boiler Code)
PG9 all the materials are there.
Perhaps someone in POWER can assist you, ggod luck.
ER

 

[davefitz]

The answer depends on how large the reactor is, and this then leads to the max permitted wall thickness for thermal stress considerations. There may also be other metallurgical considerations, depending on what reaction is proceeding in the reactor. I assume you are applying this to supercritical oxidation based on the 600C design temp.

The new creep resistant alloys P91, P92, P112 are some ferritic alloys that can be used for the pressure resistant boundary, and one might clad the interior with a stainless steel if the reaction requires such properities. There may also be hydrogen damage or other effects that need to be dealt with depending on the reactions.

One big issue is finding a foundry that can fabricate the vessel properly, given all the special metallurgical requirements of these new alloys. The shop will need to hire a metallurgist to confirm the shp procedures will retain the high allowable stresses that the code assumes the material has retained, but which can be degraded by improper fabrication procedures. The best bet is to have a large boiler mfr ( Alstom, BW, Fowster Wheeler, MItsui Babcock, etc) either fab it or review the fab procedure.

 

[MJCronin]

ck....

Lets see now....600 C/250 bar is about 1112F and 3625 psig

These are conditions not commonly found (together) in the US power or process chemical industry.

Your are into some expensive, cutting edge stuff....

"davefitz" has some good suggestions.....

Look at these links also

http://asme.pinetec.com/ijpgc2000/data/pdfs/15049.pdf

http://www.thefabricator.com/Articles/Tube_and_Pipe_Article.cfm?ID=410

http://www.materials-edge.net/download/Plant Life.pdf

http://www.babcock.com/pgg/tt/pdf/BR-1586.pdf

What is the size of your reactor ?

MJC

 

[cktayum]

Thanks MJCronin,

Yes, as per Davefit said, is for SCWO application. Our vessel is quite small in size, is just about 5" ID and 7" OD. height about 4m. We are looking for a material which can stand this high temperature and pressure, corrossion is not an issue as the design itself has minimised the corrossion problem.

Thanks for your advise.