Rotovaps

Hello good morning,

I’m a wannabe new guy. I’ve done a lot of reading. I know what types of equipment I need to buy for the products I want to make. I can only buy one at a time. So the first thing I want to buy is A ROTOVAP.
I’m setting up a small capacity lab to start because that’s all I can afford.

My question is: What brand of Rotovap should I buy? Probably 3litre will be in my price range. Is buying offshore products acceptable? Or is the quality inferior to something built in USA?

Thanks for your help
Rudedog

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Chinese rotovaps work good enough to start off. I would however look here for a used unit here or even ebay for a used non china unit.

dont forget you will need a chiller and vacuum pump too.

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Right. Thank you. I have a vacuum pump already. I’ll start to look for a chiller.

But is is the proper type of vacuum pump?

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Ill have to some more reading again. I have a 7 cfm used for auto air conditioning. I’ve used high vacuum equipment before and I dont think that that high of a vacuum is required for this application. From what I recall reading anyways. Am I wrong?

You can use that vac pump, but it way overkill and you run the risk of killing the pump by sucking in etoh vapor.

Welch wobl is perfect, or any diaphram pump.

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Ok. I’ll look for a filter for it. Not sure what I can get. Ill have to read up on that. There are cold traps or filters.

If you are hacking that fridge apart and wanting it to work again - you’ll need a vacuum pump and some refrigerant and a scale to weigh your refrigerant. And a set of gauges.
I don’t think a chiller is that much money - depending on capacity.

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Read the other comments in the thread they are about vacuum pump selection and the maintenance needed when using the wrong pump (very frequent oil changes). That is why I linked it…

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We are specilized in rotary evaporator and chiller machine many years in China,qualified quality with an zero complaint since the beginning of the cooperation.
3L evaporator is ok,do you need automatic or manual?Different models are can be provided.Chiller also is needed,may I ask what’s the lowest temperature do you need?How about DLSB-4/15.

Thank you

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First and foremost—if you want to buy a rotovap, I would place the glass as the third most important component behind vacuum and chiller. You say 3L—at a minimum I recommend 5L—it’ll still fit on a counter, but large enough to process 2.5L batches or as small as 500mL - 1L batches.

So, here’s a run of the mil 5L

It’s got 6,800BTU/hr (roughly 2kW) of heat output, so you need a nearly equivalent chiller—it doesn’t need to be an ultra low chiller, -20C is just fine. I would recommend something with at least 25% more chilling capacity at 0C.

-20°C Recirculating Lab Chiller UC2020 | USA Lab

That would work fine—some would say it’s overkill but I don’t believe in such a word when it comes to chillers in a cannabis lab.

Vacuum should be a diaphragm type vacuum—do not cheap out and get a rotary vane pump, for the love of god. This is my biggest pet peeve, walking into a lab with a rotary cane attached to a rotovap, it is too fast and too deep for the application. You WILL spit oil everywhere, it WILL smell like shit all the time.

Here’s a diaphragm pump that would work:

If you wanna cheap out on the vacuum, you can use a water aspirator like this:

Personally, I don’t cheap out on equipment—I would recommend you budget around $6,000 for a 5L with chiller and vacuum. You can do it for around $3,000 but it won’t be as dependable of a unit.

0.02$

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Hit up goldleaf labs. Great quality and excellent service.

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Startup tip: forget about the chiller for now. It’s winter time and you can run a rotovap that small on a bucket of ice water.
Chillers are expensive. Icicles are free👍

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Welch wobl diaphram pump for 600. Perfect for 5l roto and a chain of 3 buchner funnels for filtering. And great to use to vac seal Mason jars.

I run that same unit (5l rotovap) . We have 4.

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I disagree, a strong chiller is always my starting point for a good lab. Powerful temp control is underrated.

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I use a chiller on my 50l. I still run my 2l and 10l off a 55gallon barrel with a little water and a bucket of ice. It’s hard to get the hill billy out of me I guess🤷‍♂️

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What’s your recovery rate?

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The 10l does 5l an hour on ice water. I have a coil on the feed to my 50l I usually put in a bucket of hot water to warm frozen fluid on it’s way from filtering to the 50l. I’ve been thinking about rearranging things so that coil sits in the barrel and chills the water for the 10 and 2l.

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