I’m looking at purchasing a -86°C chest freezer and doing some mods to it.
My goal is to inject about 20L of cold etoh in a centrifuge at a time, total of 160L total in a day.
My plan is to put stainless steel coils in series inside the chest freezer and drill some holes on the lid. I can buy some bulkheads to connect from the outside. I figured I can try just setting the coils inside the freezer or perhaps filling up the freezer a bit with dry ice. This way the ice will last longer than doing it at room temperature. And there will be more surface area of contact.
Or I can put the coils inside buckets filled with ethanol and let them get cold that way.
Perhaps there’s a better cheaper alternative way to getting etoh cold. Also, the coils in series may not be enough to reach -40°C - -60°C or I may need a bunch of coils.
Let me know what you think? Or have done?
Any input helps.
Just fill it with regular ice, surrounding the coils. As long as there’s no heat load, the coils are long enough, etc, this should work just fine. I’m essentially doing the same thing with a stand up -86c unit to pre-chill alcohol coming into my jacketed reactor. There really isn’t a cheaper option…
Use a 50’ Stainless steel wort. Set the wort inside of a 6 gallon gatorade cooler and fill the cooler with dry ice and isopropyl. This will get you to -70c. If you’re not seeing the temp you’d like simply ad another wort and gatorade bucket in line. You can move the alcohol by using a pump and vacuum or nitrogen and positive pressure. Hope this is helpful.
The freezer is capable of bringing 60L to -86 C in 24 hours any more than placing liquid in and waiting 24 hours it is not capable of
I worked on a 200L reservoir with denatured ethanol and 4 coils inside
Passing room temp solvent treu the coils but after 40 L game over the denatured ethanol has lost to much
Cold and it takes hours to get back to temp
I think as long as there’s no heat load. With enough surface are through the coils I should be able to hit my temperature. Going to have to do some testing.
Found a few worts already. Love the 50’ of tubing. Most of the coils I’ve found in the past are <40’. Only thing I’m thinking of now is how much dry ice will I need per day, week, etc. Thanks !
The heat load is the ambient air that touches the coil outside of the freezer and the fuge itself acts as the heat exchanger. I don’t think that freezer will be able to keep up with that demand. The refrigeration units are not meant for a constant load on them
Just a heads up, I discovered nybrewsupply. As far as I could see, their prices are way better than anywhere else, and they have 50’ coils, that have both the ins and out port extended up. They fit perfectly in an igloo round cooler, and can come with a variety of fittings.
This may be a KISS situation. If you get a Thermo Fisher or similar 24cu ft upright freezer you can fit 18 of these in it:
Fill it up, get it down to temp, and rotate full ones in as you remove them. You’ll only use about half of them each day, so it should have no problem getting down to temp each night. If you have a regular chest freezer next to it to stage pre-cooled jugs to rotate in as you remove them from the ultra-low, you’ll definitely be fine. No mods or plumbing needed.
Great idea. The pre-staging should help make sure they are reaching temp over night. That was one of my concerns. If I can fit about 18 in them that’s 90 gallons or 340L which is enough for 2 days. Thanks