Need Help with Short Path Distillation

Hello all,

        I'm looking for some help in running my short path distillation unit. I can provide pictures and videos if need be. Few things to note at first, we do not have vacuum control at all so I'm unsure if it is even possible to fraction out  Heads, Hearts and tails. We've had a few decent runs with 88%ish product however our last few runs have been awful. It seems that lately, the vapour does not condense and is simply pulled through  the cold trap and into the vacuum.

We’ve been running our chiller at 20C as that is all it is capable of and increasing to 50-70C if we get a flow issue on our cannabinoid fraction through the distillation glassware however we havent even been able to get to the point of collecting the main part lately.

It seems like we get vaporization and that it often circulates the flask or moves up to the condenser only to get pulled back down in to the flask. Once I swapped out for a larger vac pump (at 220 C), immediately I seen refluxing action but after a few seconds the it dissipated and the vapor was sucked straight through the entire unit, through the cold trap and out the vacuum tubing. I am going to get a video and some pictures for guidance as it is difficult to explain. I try to convince my partner we are useless without proper vacuum control and a decent chiller to no avail as our first run miracously worked fine. Any help would be appreciated.

I also noticed quite often we are up to 160-200 Celcius and our head temp is still 25-30 C, is this indicative of a leak or lack of vaccuum to suck the vapours up to the head? Thanks alot.

No vac gauge ?
Then I can t be of any help
A leak a cold not well insulated head
Who knows

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You need a vacuum gauge. It will help you nail down your process, as well as let you know when things are going wrong. If your vacuum gauge is reading over ~300 microns, you will not be able to distill.

From what you said, it sounds like you have a few issues. Do you have all of your glass to glass joints greased? You should be putting high vacuum grease on the top 1/3rd of the joint.

What kind of vacuum do you have? you need to have a strong enough 2 stage vacuum to be able properly distill. It sounds like you just upgraded your vacuum, what kind did you get?

If you are seeing vapors in your setup while you are distilling, you definitely have a leak. I think that leaky joints is a good place to start, but before that, get a vacuum gauge!!!

Thanks for the response, I do use vacuum grease, or fitting suck and we have been parafilming to decrease in leaks, this system is a small desktop cheap set up just for R and D before we get into a huge wiped film unit we just need some distillate for cart testing etc. The vac gauge I sourced cost as much as the unit I couldn’t find a decent one under 500. In regards to the chiller which is a glorified waterbath, we can’t get it below 20 celcius which I figured would be an issue however we did get a few decent runs at first.ill get some pictures of the set up

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What condenser is it you want to chill with the water bath below 20 C
? For I can not think of one that needs that

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You can get a used 900 dollar sensor on eBay for 50 bucks.

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Bullseye is about 500
Top of the line gauge

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Get anything a used yellow jacket hvac gauge and a flare T will do it

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I’m having similar issues. We use ate digital vac gauge from our rotovape. It reads 0 tor. I’ve assumed we don’t have a vacuum leak because of this, but we are having similar issues. Did the vacuum gauge help?

Just use a bucket filled 2/3 with water freeze ober night and then use a sous vide when your at distillate.