Heat transfer fluid question

I’m waiting for my new jacketed sleeves to arrive. Just wondering about a redneck chiller. I hear a lot of people using alcohol with dry ice “double boil” on an pot of alcohol and pumping the cold fluid through jackets.
Call me crazy but I just don’t like the idea of pumping such a flammable fluid around. I have acces to a free 5 gallon bucket of propelyne glycol heat transfer fluid. Can I chill that with the dryice and alcohol slurry in a double boil and pump it through my jackets instead of alcohol with the same or similar results

No, look at the freezing point of pg or even a pg water mix.

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Ya -50 will a double boil even get it that cold

If youre set on doing this, whichbi would advise not to, then I would make sure to start pumping the fluid first, then add the dry ice underneath. It may not actually freeze but your pump most likely won’t push a thick syrup

I’m not set on it but free vs buying alcohol. Thanks for your input tho I’ll probably take your advice.

Probably wiser than taking mine :slight_smile:


Get some dry ice, a gallon of ethanol, and a blow torch. Make a dry ice slurry, and try to set it on fire.

The flash point of ethanol is 16C. at -70C it won’t burn.

Even without the oxygen free atmosphere you’re trying to light it in…

Edit: now submerge the blow torch in the solvent like the pump would be, and try and light it.

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You need help :joy::joy::joy::joy::joy:
No one on this site has such a great way if explaining things
I wonder if he realizes that deu to cold the vapor pressure will drop in the cold by wich it doesn t gasify and lighting it is nit a option :joy:

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there is also a write up on the pond pump in a dry ice slurry here: Diaphragm pump that can handle -80°C - #3 by Dred_pirate


what is the temp of a dry ice ethanol slurry? see Ice bath tech - #16 by cyclopath

50:50 glycol will become slushy and hard to pump somewhere between -30 and -45C especially if the bath it’s in is at -70C or better.

methanol, ethanol, isopropanol and acetone are all usable heat transfer fluids at -50C. HC-50 (potassium formate) is the only non-flammable one I’m aware of. At -80C I believe your choices start to get pretty limited.

This is 100% glycol not a mix but judging by what everyone is saying I’ll go with alcohol

Thanks everyone I’ll scrap the glycol

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It’s 100% glycol?
Do you know what that means for it’s freezing point?

If the object of the game is to understand the problem, you should chase down the answer to that.

All sorts of useful stuff at engineeringtoolbox…


Get the pond pump and use isopropyl alcohol. Not just any pond pump it’s gotta be a magnetic drive pump

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I have 2 eco plus 633’s I was planning on using one for hot one for cold