Totally can. I forget which post it’s in, but someone did exactly that. They put dry ice into the bath and lyophilized some fresh frozen that had thawed and re-frozen a couple of times. He had good results also. I totally forget whom it was. Hopefully they’ll see this and mention something!
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What would be the reasoning of my chiller not actually chilling? Have it set on cold/cycle, and stays the same temperature. Ran it for like 1-2 hours and if anything it went up a hair, My workplace was hot today but not even flinch the temperature??? Theres gotta be something im doing wrong or is wrong! help my first chiller…
What type of fluid are you using?
E Glycol and water 50/50
Probably needs charged, look to see if you can find a leak at a soldered joint. Bought new or used?
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I’ve found running a roto with less vacuum and higher heat performs better.
Chillers are more powerful the less they have to chill the fluid going through them.
Brand new, never used.
If your using glycol, don’t go too low on temp.
Just set it @ -6c and your roto bath at 50c. Set your pump regulator @100 and work your way down on vac from there as you see fit. )If your using ethanol)
Where did you buy your glycol from and how are you liking this chiller? I’m thinking about ordering one myself but haven’t decided yet.
Our company is selling chillers, what size do you need？Maybe I can help you.
Two weeks ago his chiller was not getting cold. I’d personally avoid import chillers for lack quality in after-sales service. You really don’t need too cold of a temp for your condenser if you’re dialing in the right parameters, as others in this thread have implied. Especially for a 5L/benchtop Roto.
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So I actually got the chiller working, it stays at a 0degree Celsius. Up too 60-70 celsius on water bath/boiling flask. It does the job but still ethanol gets through. No more mofo ice though lol. I wouldn’t use this chiller on anymore then a 5L
Edit: chills to -30 Celsius but doesn’t hold once roto vape is going. Ends up staying at 0-3 celsius
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No reason to have your bath so high if you have adequate vacuum. Try 50C, Vacuum at 275 mbar and your chiller at 0C.
EDIT: Ethanol is probably getting through because your bath is too hot. It’s evaporating faster than it’s condensing.
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Our chiller gets down to -30 to start. 50l roto. Single, two stage condenser. With the water bath at 25C, 80rpm, the chiller stabilizes about -17C but I still pull a bit of solvent through the diaphragm pump (Welch 2052) which pulls to -730mmHg. I pull maybe 3l/hr, haven’t really monitored it because I’ve got too many other things going on at the same time usually.
Had a guest worker in here the other day (Not *my * idea!) who had the temp up to 38C, 110 rpm, telling me how to “optimize” my rotovap. You shoulda seen the amount of alcohol blowing through the pump!
Your vacuum pressure is a bit too strong for efficient solvent recovery. At that bath temperature, ethanol evaporates around -700mmHg, or 80 mbar. Try this parameter out with the same condenser temp and see if that helps reduce the amount of solvent going through your pump.
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In order to drop my lessen the vac, I’d have to let air into the system. In doing so I also allow moisture and the air carries the solvent through the pump, doesn’t it?
Use a regulator or Woulfe Bottle to adjust vacuum pressure. Too strong a vacuum is going to pull the solvent through before it has a chance to condense into the receiving flask. Air doesn’t carry solvent to and through the pump, vacuum does.
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Hi do you maybe know the thread ? I am looking for this and cant find it in the search bar thx
Correct query:
https://future4200.com/search?q=lyophilize+Rotovap
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