This is probably a long shot, but does anyone in the San Diego area have a chiller that would work for a 20L or 50L roto that I could rent for a couple weeks? The compressor just went out on one of ours. I have two Polysci Durachills on order but they won’t be here for a couple weeks.
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Go buy you a shit load of dry ice and very low freezing point liquid (THAT IS SAFE TO BE EXPOSED TO ATMOSPHERE) and bucket.
In bucket: dry ice, liquid and copper coil (more surface area is better).
Pump your cooling liquid (probably EtOH or a brine?) and pump it through the condenser of the rotovap.
Pay special attention to ensure you’re not leaking coolant.
Pay special attention that you’re not offgassing too much CO2 into your space from it sublimating off dry ice.
Pay special attention to the liquid you use with the dry ice.
This is the cheapest, quickest solution. Less than ideal, doesn’t work as well as you want, but it works.
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I did this with glycol and Jesus Christ is it annoying
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Don’t forget that pumps really hate to push co2 saturated liquids! They will stop working and just push foam so you have to have some sort of reverse double boiler setup to keep the liquid you pump thru the system separate from the liquid you are directly loading dry ice into
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What temps u gotta hit? U can always just go ice water lol.
That’s what the copper coil in the bucket is for, fluid that runs through the lines never touches the dryice.
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But increasing circulation allows you to get more cooling capability from your chilling solution.
Yeah my concern doing that was the CO2 venting. The compressor is still working a little, it just can’t keep up, so I plumbed the jacket of a spare 50L reactor in line and filled the cavity with dry ice and ethanol. That allowed me to close it up and vent the top to a fume hood with some hose. It’s holding at 10C for now, we’ll see how long it lasts 
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an overhead stirrer would do the trick, just in the bucket with the pump tho as all that dry ice will make for some major turbulence
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Well done, sir. It’ll hold as long as you continue to add dry ice.
Obviously be careful for the offgas when you reopen
So its ok to use the copper tubing instead of stainless for a sort of wort chiller in between chiller outlet and condenser inlet? I’ve read the optimizing your rotovap section, I was under the assumption only stainless steel works?
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Realize it’s a little late, but purhaps someone will find it useful.
@TheGratefulPhil is running a coolant loop. Not running product through the coil.
If you’ve got product touching it, you want stainless.
See: Do large scale Ethanol Extractors use copper condensers or just stainless steel? for discussion
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What @cyclopath said. Copper is great for cooling lines that don’t contain hydrocarbon or product
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Re-reading: I’m an idiot.
@Backyard_Boy is asking abouT adding the coil between the chiller & condenser. Where copper is perfectly ok.
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