Recently I've been messing around with heat pipes -- specifically, trying and failing to replace the water coolant charge in the standard heat pipes with acetone, which would work at much lower temperatures.
(This would work better if I used, oh, I don't know, vacuum, but I would need to get cryogens and rig up a vacuum adapter to the pipes).
These are familiar to anyone who has ever built their own computer since they are very common in laptop and higher performance desktop cooling systems -- but until now I had never encountered them on their own. As it turns out, you can buy them from Digikey -- and they're inexpensive -- anywhere from 3mm to 12mm diameter, various lengths, prices $5 to $15 depending on size. Once the hot end heats up to around 40-60 C, they begin conducting heat at several orders of magnitude over a copper rod, with no moving parts.
It occurs to me that they might be interesting as fusor stalks -- you would not need to deal with the typical issue of having to electrically isolate a liquid cooling system, or for that matter, of having to seal one -- you just need to be able to accommodate a nearly unsolderable copper rod.
Pictures of my failed re-charged pipes to come later. I'm not sure what the most practical way of sealing these are -- I wonder if annealing and Vise-grip pinch off is actually capable of making a hermetic seal.
Heat pipe cooling
Re: Heat pipe cooling
I don’t think vise grips are the answer. Pinch off seals are normally made with more of a cutter type tool. Try using large diagonal cutters.
- Rich Feldman
- Posts: 1471
- Joined: Mon Dec 21, 2009 6:59 pm
- Real name: Rich Feldman
- Location: Santa Clara County, CA, USA
Re: Heat pipe cooling
We use tons of heat pipes at work, about the size of pencils.
An easy demonstration to do with a loose heat pipe:
try stirring a mug of very hot coffee or tea or chocolate.
The handle end gets too hot to touch within a couple of seconds.
Hmm ... what would be a good working fluid for heat pipe at 500 to 700 °C?
Stir a pot of molten aluminum and see the handle end soon become red hot.
Looks like annular heat pipes can be used as Isothermal Furnace Liners. Tube furnaces with 0.1 °C uniformity are practical.
Non-hermetic Pressure Controlled heatpipe systems can help when 0.005 °C regulation is needed. https://www.1-act.com/innovations/heat- ... atibility/
An easy demonstration to do with a loose heat pipe:
try stirring a mug of very hot coffee or tea or chocolate.
The handle end gets too hot to touch within a couple of seconds.
Hmm ... what would be a good working fluid for heat pipe at 500 to 700 °C?
Stir a pot of molten aluminum and see the handle end soon become red hot.
Looks like annular heat pipes can be used as Isothermal Furnace Liners. Tube furnaces with 0.1 °C uniformity are practical.
Non-hermetic Pressure Controlled heatpipe systems can help when 0.005 °C regulation is needed. https://www.1-act.com/innovations/heat- ... atibility/
All models are wrong; some models are useful. -- George Box
- Rich Feldman
- Posts: 1471
- Joined: Mon Dec 21, 2009 6:59 pm
- Real name: Rich Feldman
- Location: Santa Clara County, CA, USA
Re: Heat pipe cooling
Before today I didn't know that pinch-off seals could be made with nothing but tube metal.
Found out lots from one maker of tools for the job, starting with http://www.pinchofftool.com/node/5
They mention importance of annealing, and mechanical cleaning of the surfaces to be welded. How 'bout something like a Q-tip made with steel wool, or a wire brush made for cleaning gun barrels?
.
Could you use hard steel dowel pins as pinching dies with well controlled shape?
Found out lots from one maker of tools for the job, starting with http://www.pinchofftool.com/node/5
They mention importance of annealing, and mechanical cleaning of the surfaces to be welded. How 'bout something like a Q-tip made with steel wool, or a wire brush made for cleaning gun barrels?
.
Could you use hard steel dowel pins as pinching dies with well controlled shape?
All models are wrong; some models are useful. -- George Box