This is why VTA has a chiller cold trap at -40 first then the LN2 coldtrap
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The difference is the short path has an internal condenser and the rolled film has an external condenser.
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@coppertop - Rolled film in the CTS definition is with an external condenser in addition to a cold trap (not in the rolling chamber) and wiped film has an internal condenser and only a cold trap. They sell rolled films for lights stripping applications (ethanol and/or terpenes) and wiped films for distillation (as a product) applications.
@magister I’ve never run a CTS with a cold trap not ran on a Julabo cooler, I’ve never experienced the problem you’re describing except on a KD-30 when I ran a few buckets of failed sauce. My cold trap became saturated with freezing terpenes and the temp difference made my catch brittle, which snapped when I tried to touch it to empty it. However my cold traps were -30 (kd-6), -45 (kd-10), and -60 (Kd-30)
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Chemtechs definition of roll film is incorrect.
Look up the lab society inconn 2 stage
Or deltas rolled film
Sounds like chemtech is pulling a fast one with there wording
Actually all the chemtech units use rollers.
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Wow with no springs.
Yea I wouldnt buy a roller that doesnt have springs
The whole thing about a rollers is they create a thinner film by using springs to get a thinner film
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Seemed to work fine to me
Here is the president of CTS’s wording on the subject (a chemical engineer, so terms may change?Idk)
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Working fine and best engineering designs are 2 different thing.
I’ve ran Chinese wipers with rollers without springs, they perform worse then a wiper since the rollers use centrifugal force to create the thin film.
This is a horrible design
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https://www.instagram.com/p/B4Qqg34ha6F/?igshid=1aelheex0z2fx
If you know wiped film you can pretty much get anything to work
Obviously that machine could never keep up with the VTA, idk if a chemtech could either since the evaporator is so short.
That’s the problem with this machine, its evaporator is like 12 inches
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Most of my WFE experience boils down to(huh get it?) the glass versions of VTA’s VDL series and everything from 2" to 6" Pope WFE, stainless and jacketed. So I can’t really talk much to any of the Chinese WFEs but I definitely have some opinions about VTA and can answer your questions.
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Heat tape is pretty unreliable but you can make it work. Disadvantages being that it is not as precise as internal jacketing or stainless steel jackets. That being said, I’ve experienced channeling problems inside fluid-jacketed components. For example, I’ve seen channeling occur in the feed flask for the VTA which caused distillation efficiency to drop due to the crude being under-heated. We ended up having to change the heat transfer fluid. All that being said, jacketed is way better than heat tape.
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I don’t have much to say about hemispherical vs cone-shaped cold traps. I feel like I’ve only ever seen cone-shaped though.
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For the most part, I don’t see the advantage in upgrading to carbon carbide wipers. It seems like you might be able to use adsorbents with that which may be worth experimenting with. I will say the wiped assembly on the VTA units I’ve used are susceptible to breaking at the metal bracket. A few seem to snap every few months.
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High-quality gear pumps are amazing. Dialing in feed and output rates is one of the key components to ensuring quality distillate. The gear pumps that come with the VTA are dependable and accurate. Pope gear pumps also seem quite robust although I am not as experienced with those.
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Can’t really go wrong with more sensors. Could help you dial in any potential problems but I think that the hand-held infrared heat-sensing guns seem to work alright as a cheap alternative. They are not super accurate though.
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This is all super great info, thanks guys. I hope this helps people know what they should be looking for when picking suppliers - there is a lot of expensive garbage out there, some super cheap crap, but there are also some good ones at reasonable prices if you look hard enough I think.
I operate a UIC Wiped film. It’s one of their older (4 years?) models from Precision. All glass which I love because I can really see whats happening as the crude runs down the evaporator and I can adjust the feed rate and spin rate accordingly to give me the best ratio of color/residue.
I have read the threads regarding feed temps that suggest a high temp, one close to the evaporation. temp but I routinely feed at 70-80 deg C with a evaporator temp between 160-165. With the diffusion pump I can easily pull 7.5 X 10 to the -4 which make for great separation capabilities. One lights run to remove terms/volatiles and 1 polish run with results in the low/mid 90’s for THC and mid/high 90’s total canabiniods. It’s not fast. Lucky if I can get 1L/hour.
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You do not need carbon blades
RE: my above post. The unit is not a spinning band but rather a wiped film. My bad.
Kind late but it just got a like so I thought I better clarify…
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