very high temperature oil

[sensorman]

Does anyone know of a heat transfer fluid that will not vaporize at a temperature of 455 celcius while under a pressure of 3000 psig? I can get to 371 with dow corning 710 oil but this still isnt what I need, also the viscocity is much too high at lower temperatures, I suspect the only thing available is a liquid metal alloy.

 

[25362]

Could molten sodium or sodium/potassium alloys be a candidate? I read molten sodium is used as heat-transfer medium in liquid-metal fast-breeder power reactors. It has a viscosity of 0.68 cP at 100 celsius.

 

[phex]

contact Mr. Harald Plöchinger at hpploechinger@dow.com for info about dow's heat transfer fluids. perhaps he does know of a suitable solution. if there is a possibility to use a dow product, he will know it.

 

[unclesyd]

I don't think that any organic heat transfer fluid is going work above 700°F and your temperature is approaching the detonation point of the Biphenyl based fluids. This temperature is 927°F. Been there and done it.
Check the NASA tech briefs as they have done a lot or research in this area. There is a lot of work been done under the auspices of the NRC on high temperature heat transfer.

We used a molten salt as a heat transfer medium on some very large reactors. The salt was used to extract heat from the exothermic reaction and generate steam. It was heated electrically to start/maintain and circulated with a pump. This wasn’t primarily my area but if not mistaken they ran at your temperature, 850°F @ atmospheric.
You might look at the processes for manufacture of organic anhydrides/acid by the catalytic oxidation of Butane.

 

[lubes]

Might want to contact Petro-Canada Products, as well. I suspect that a that kind of pressure you should not have much of a problem to keep a fluid (oil based) as a liquid. Here is a Web link, anyways, if you want to ask Petro-Canada:

http://www.petro-canada.ca/eng/prodserv/specialtyfluids/6947.htm

 

[TD2K]

Cal-flo are good heat transfer fluids but they are still hydrocarbon based. As unclesyd has already said, I don't think any of those fluids are going to hold together at that temperature. It's not a problem of just keeping them in the liquid state, it's a matter they literally decompose because of the temperature and molecular energy those temperatures entail.

 

[moltenmetal]

You're into metals or salts at these temperatures. Just about any hydrocarbon or other organic fluid will coke at these temps. You're well beyond the point that the silicones fall apart too.