Rotary Evaporator help

Hi I just started making crude recently and invested in a AI 50L rotovap paired with a polyscience 6860 chiller with a welch 2163B. My recovery is about 4-5 gallons an hour, is this normal?

You should be around 50 liters per hour when setup proper

Let us know your parameters so we can try and figure out what your doing wrong. If you can show us some pictures @cyclopath says they are worth 1k words.
I’m confident you didn’t make the post to have someone tell you your 50l roto is supposed to do 50l. :man_facepalming:


we see about 5 gallons per hour on our 50l. Running at 65c water bath, -10c - 0c condenser, rotation at 50, and vac at 28 Hg. I could probably get it faster if I preheat the solution going in or upgraded the vacuum pump. I know increasing the rotation will help also but it doesn’t seem sturdy enough to safely spin it faster.


If you don’t tell people what they are to be expecting they settle on slower rates and unaware thier roto isn’t working right.

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It’s not cool to be making jokes about people with diseases.


This guy can’t get out of his own way. :man_facepalming: I think you should read the title of the post. It doesn’t ask how many L an hour my 50l roto will do. It’s very clear he asked for help with his 50l roto. Three post here with one making fun of people with disabilities and two with nothing constructive.


Not that I believe for a moment that one can get 50l an hr out of a 50l rotovap without changing the laws of thermodynamics, but assuming it’s doable, what the OP needs is direction on how.

@Montroller mentioned preheating the incoming solution, which is a great start. Including their operational parameters and output allows OP to compare.

I’m just going to point at previous discussions ( and mention that spraying into an almost empty evaporating flask is faster that filling the flask and then turning it on.

Edit: AI rotovap lists 6000w heater. 50l of ethanol requires closer to to evaporate. so 50l/hr is a fantasy


case of the pot calling the cat black there


We ditched rotos 2 years ago and invested in a CBG Biotech SRS unit. Our unit takes all the labor away when using rotos. Plus we can also decarb on the SRS unit. This was great getting away from transfering to glassware and into our vac ovens for purging and decarbing. One machine does both solvent removal and decarbs. . They have an EtOH machine coming out soon to I beleive.


pics. I wanna see the thing


Website has a video.

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“OVERPRICED POT STILL ALERT” :rofl::joy::roll_eyes::pensive:



I’ll upload some pics. as soon as I run it later I’m currently washing right now. My water bath is set at 80c with rotation maxed out at 110rpm. My vac is pulling down to 28-29hg and chiller is set to 10c but can never hold at that temp. Does my chiller not have enough cooling power?

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probably not enough to keep up with 80c. try to find a spot between 50c and 80c that your chiller is most efficient. also I dont think you need your rpm that high I usually run it around 50-60 rpm


@bsanchez244 what’s the dwell time on that isomerization station you guys got boiling up over there?

In an ideal world, you want an almost empty evaporator with a film coating the entire surface. Rotating faster than that gives you a thicker film, and slows you down. Feed in just enough tincture to make up for loss to evaporation. turn your cold all the way down (or even a degree lower than you can maintain) and adjust heat till the chiller stabilizes somewhere that makes sense (solvent not coming through your vac pump).


how many gallons do you want to recovery per hour? we can set you up to increase plus we have our lab site and teach how to increase productivity and get higher recovery if that is what you are looking for

check out the optimizing roto thread, it has all the ways you can beef up your system. Still, at the end of the day it will not do 50/L an hour


Do you recommend a rotovap for solvent removal of a heat sensitive product?