I believe the center pic with only an external condenser is called a wiped film evaporator and the right pic with the internal condenser is called a short path evaporator. Short path evaporators are considered a subset of wiped film evaporators and they’re both subsets of thin film evaporators.
I’m not sure but I think that’s what the three bubbles at the top of the pic are meant to represent. Short path fits in the smallest oval, then wiped film is the middle encompassing short path and then thin film is the largest, encompassing them both.
The term rolled, I believe, does indeed refer to the way the film is applied (blades vs rollers).
Both the center and right pic setups could be rolled or wiped or something else (I think they also offer blocks?).
I can’t access the paper you linked but I went to the first Chem Tech presentation on hemp oil processing back in 2015 and I’m going off my binder of info from that.
From the paper: Large circle “Thin film evaporators / Falling film evaporators and degassers”, medium circle “Wiped film Evaporators”, small circle “Short path evaporators”
So yeah - you’re right there.
From the Center Image, its called a RFL
"The RFL series of laboatory WFE systems (RFL signifies “Rolled film Laboraotry) are typically configured similar to the above ilustration.”
All of the units CTS makes use rollers. From the paragraph below the short path “Similar to the RFL evaporator, rollers are used as an alternative to wiper blades with the added benefit of additional evaporative surface and an agitation effect which facilitates the evaporative process. Note the condenser is internal to the evaporator reducing molecular impedance to high vacuum.”
text me at 562-521-4057. We’ll set up 30 mins or so.
If there is strictly a pH issue with the oil totally unrelated to the wiper itself, when you dissolve the crude into ethanol, then add citric acid, if the issue is pH then the dark oil will instantly turn light yellow. If you want to do this test you only need a tiny amount to check. You could dissolve 100mg in 1ml of ethanol, but if you can’t measure that small you can do 1gram in 10 ml or less of ethanol then sprinkle in citric acid.
Whenever I’ve had color issues and I’m not sure if it’s a single issue or even multiple issues, doing this will essentially isolate the focus to the front half or back half of the process.
I while back I couldn’t stop making purple and red disty (water clear in the cart) but the bulk jars were making the owners weirded out. Did a quick acid check on a gram and the color corrected itself. Then I dissolved another gram in pentane and washed it with water, and the water turned piss yellow. Turned out the extractor who was supplying the wholesale bulk crude in buckets for me was re-using his ethanol over and over without re-proofing and it was less than 160 proof for his runs, pulling out tons water solubles.
Figure it might be a rolled film issue, but it sucks chasing distillation and wasting time when that’s not the problem. Helps to be confident even the crude is not an issue if someone tries to help and is like “oH nO, iT’s tOtAlLlY yOuR pH BrO”.
If you have any activated alumina and activated magnesium silicate there are some other little tests you can do too on your raw materials.
It’s just so rare thin films don’t work when they are mechanically sound.
Was the short path run hot or with high vacuum/leaks? I’ve seen red pop up from higher temps/tails, and in that case it was difficult to remove by distillation alone. A simple clay/non-polar filtration should solve your problem in that case without losing much. Finding how this was extracted/distilled in the first place could give you a good starting point for refinement.
I’ve distillled at that low of temp/vacuum (even 130c can work), but I wouldn’t recommend it, very low throughput, reduced yield, and lower potency. Typical Chemtech polishing parameters would be more like 160-170c evap, 80-100c condenser, and 400 rpm wiper. Set your feed speed to produce 80-90% yield. No reason to waste 50% yield on a polishing pass. Are you collecting much in the cold trap?