Hello!

I am researching on behalf of a scientific team, that built a small scale circuit to heat an object (300 C) under high pressure (3500 psi). It is basically an extreme pressure cooker. We want to upscale the heated and pressurised chamber to higher proportions.

The problem we have is that to heat the chamber containing the object, we wrapped heated coils around the outside of a steel tube with a temp sensor inside. Heating like this works, but we want something to go inside the pressurised chamber so it is not exposed.

If we could find high pressure electrical isolators, I could put the heater inside the chamber and heat the specimen directly. Do you know any that might be available?

This is a scientific project so I can't go too much into detail here but can do so more in private messages. Would definitely be interested in working with someone in the UK who could also build a replica here as the current one is in Chicago.

Thanks!

 

There are many kiln lining materials that could/would satisfy your requirements. Many of them come as a plaster like consistency and could be molded to make a "U" type channel for the heater coils also. A google page for you to look at and see what I'm talking about - https://www.google.com/search?client=firefox-b-1-d&q=kiln+liner+material

 

As to feedthrough I used stuff made by Pave Technologies and they can custom make anything you want., just call or email asking for an applications engineer. We ran temps about 350 C in a pressure vessel at about 2,700 Kilopascal. We heated from outside the vessel using heater bands so I am not much help there. Also as to heating elements and in addition to what shortbus mentions I used Watlow Elements and again call or email asking for an applications engineer. They can custom manufacture anything you want.

Ron

 

We heated from outside the vessel using heater bands so I am not much help there.

I should have mentioned heater bands. They would put the heat right where it's needed.

 

I should have mentioned heater bands. They would put the heat right where it's needed.

I agree but they seem to want the heat source inside the vessel. We had Watlow custom make the bands.

This is a much younger me, maybe 25 years ago.


Each half of a band is 240 volts and 3 KW so we had 6 KW per band at 480 volts. There were 72 bands on each clave.



Then large overall insulated covers went over the entire affair top to bottom. The vessel ID was 24" and wall thickness was 3" of 316 stainless steel. All in all about 40' tall. We had 6 of them when I retired and now I hear there are 8 units. All the wiring is AWG 10 and rated for 1,000 F. The insulation in the covers used Refrasil and where you see the tape on the wires it is Refrasil tape. It gets toasty in there.

Anyway the thread starter seems to now be set on putting his heating on the inside so I guess inside it is and I liked your suggestion for forming the heaters.

Ron

 

I agree but they seem to want the heat source inside the vessel. We had Watlow custom make the bands.

This is a much younger me, maybe 25 years ago.
View attachment 274331

Each half of a band is 240 volts and 3 KW so we had 6 KW per band at 480 volts. There were 72 bands on each clave.

View attachment 274332

Then large overall insulated covers went over the entire affair top to bottom. The vessel ID was 24" and wall thickness was 3" of 316 stainless steel. All in all about 40' tall. We had 6 of them when I retired and now I hear there are 8 units. All the wiring is AWG 10 and rated for 1,000 F. The insulation in the covers used Refrasil and where you see the tape on the wires it is Refrasil tape. It gets toasty in there.

Anyway the thread starter seems to now be set on putting his heating on the inside so I guess inside it is and I liked your suggestion for forming the heaters.

Ron

 

Hello everyone! So sorry for the late reply, I didn't have email notifications on, so I just checked the thread now.

Thank you so much for the tips! They are all great and we will definitely explore each of them to the current model we've made.

Ultimately, we want to upscale this project and make the sample we create as large as possible. Is there a system already created (high pressure, high temp - industrial pressure cooker)? It would need to have a door to insert the object we are putting under pressure. Something built like an autoclave that can run 24h+ and at the temp and pressure needed or greater.

If not, I suppose Ron's idea could do it but we would want our sample to have a circumference of around 130" and a depth something similar or greater.

Let me know if you have any ideas as you've come up with great ones so far and have made me very excited again after being stuck for quite a while.

 

I can share the following. The auto-claves I pictured were manufactured by an outfit local to me in Cleveland, Ohio USA. Formerly Auto-Clave Engineering. Today they are Parker Autoclave Engineers. They can manufacture anything anyone could want. In our situation we pumped Grade A deionized water through the system and the pumps were manufactured by Chem Pump USA. We manufactured our own Grade A water. A clave was filled and all air removed. Each Clave also had a surge tank also filled with grade A water and a nitrogen blanket on top of the water. This was for water saturation pressure. If you have a medium in your can all of this needs considered. All of the companies I have linked to have applications engineers happy to assist you with any questions. Most offer global services. I retired 9 years ago but still remember much of the stuff and who we bought stuff from.

Ron

 

I can share the following. The auto-claves I pictured were manufactured by an outfit local to me in Cleveland, Ohio USA. Formerly Auto-Clave Engineering. Today they are Parker Autoclave Engineers. They can manufacture anything anyone could want. In our situation we pumped Grade A deionized water through the system and the pumps were manufactured by Chem Pump USA. We manufactured our own Grade A water. A clave was filled and all air removed. Each Clave also had a surge tank also filled with grade A water and a nitrogen blanket on top of the water. This was for water saturation pressure. If you have a medium in your can all of this needs considered. All of the companies I have linked to have applications engineers happy to assist you with any questions. Most offer global services. I retired 9 years ago but still remember much of the stuff and who we bought stuff from.

Ron

Oh that is exciting! Thank you. I will definitely be in touch with them. I am based in the U.K so it would be a little tricky (not impossible) to ship these over but I will discuss with them the logistics. You have been so helpful. Thanks again

 

OK the UK. While I have no specific details I can share this much. The UK does have nuclear powered submarines. The nuclear powered submarines have in their reactor cores what is called a CRDM (Control Rod Drive Mechanism). Before a CRDM ever sees a reactor core they receive extensive testing in an autoclave. I doubt the UK sources anything I mentioned from the US, I don't know. This lends me to believe you may have what you are looking for locally. You seem to be looking for a small autoclave. High temperature and high pressure vessel. You are also most welcome.

Ron

 

The keyword for the search would be "hermetic feed though". I have used them for penetrating vacuum areas in industrial test equipment. They seem to be custom made, mostly. They are rather common in semiconductor manufacturing equipment also.

 

The 3500 PSI precludes regular autoclaves, which generally run a much lower pressure, always less than 100 PSI. The 3500 PSI pressure is in the hydraulic systems range, but those systems normally try to stay rather cool, below 250F. So if there is a portion of the high pressure container that does not get so very hot, then hydraulic pressures may be applicable. Otherwise the hermetic feed through devices that run a single conductor through a glass/metal/glass fitting can be used. Again, the keywords "Hermetic feed through" should work for the search.

 

The keyword for the search would be "hermetic feed though". I have used them for penetrating vacuum areas in industrial test equipment. They seem to be custom made, mostly. They are rather common in semiconductor manufacturing equipment also.

Well the thread is almost a year old but as to hermetic feed through I used mostly products from PAVE. They can be found here. Vacuum, pressure and just about anything you could want custom or off the shelf. Vacuum for helium leak detection and pressure for large autoclaves running at about 600 F of grade A water at 3,000 plus PSI. You can have whatever you want just pay the fiddler.

Ron