Torr jump on wiper (kd10)

Hello all,

We’ve recently upgraded from our precision brand cdu3000 (kd6) to their cdu10k (kd10). When making this switch our primary concern was vac pressure with the larger unit based off of this unit not coming standard with an Ln2 cold trap.

Besides size the primary difference between the units is the 10k has a “first stage”…not a true first stage but a smaller degassing chamber that material passes through first before hitting the wiper.

We had always maintained about 5 microns of torr off the vac on the kd6 (for distillate pass) We had also found that occasionally the system would not reach proper pressure when dry but would drop down as material is introduced.

Starting the kd10 we found that the vac does pull down to our standard 5 microns at startup but as material is introduced instantly shoots up to about 130 microns. All other outputs and data seem to be maintaining our same standards but this jump in torr is not ideal. Has anyone ran a comparable system and have any suggestions? Besides adding the Ln2 trap which we plan on doing .

I should note the “two stages” on this system are completely separate and run off of their own independent vacs.

Is the first stage agitated? Have you tried stripping it on the kd6 then running it into the 10k to see if you get desired results?

No, we are not running both units and don’t have the power to do so. This isn’t perfect science but we’ve been running the same material for months and I can say that the strip on the 10 stripped damn near exactly the same amount as the same material on the 6…just faster so I do think the strip was equally efficient

and results wise. My only data so far is splits return and color (I’ll have potency tonight) but so far everything seems to be of equal quality. The dist looks the same, it’s returning the same, etc

My concern with the torr is A. There seems to be a slight smell and B I do believe we’ll be able to go even faster if we can get the torr down but the machine isn’t “failing” so to speak

If you’re reporting smell then you’ve probably got a small amount of medium weight terpenes. It would make sense coupled with the vacuum jump. Small amounts can really push that vacuum level up, really restricting your feed rate. Small amounts, meaning even less than 1%, something you may not catch via color and return weight. Looks to me like an inadequate strip system design or parameters, but I can’t comment on the design because I’ve never seen the CDU stripping unit.

I think you are correct but in case I wasn’t clear we don’t only strip on that first chamber we do a full strip so it passes first and second stage then re set and do the same for distillate.

So I don’t think the problem is that first stage as we view that basically as just a “helper”

but I do think that the torr which is at about 300 microns during terp strip, isn’t adequate and then this leads to what you described. So i’m back at square one…looking for a way to improve torr :grin:

Then in the absence of any leaking seals, I’d guess it’s your process pressure from your feed rate. In which case you’d probably only benefit from the LN2 trap. That’s all I got.

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Appreciate the input. Have you ever ran your diffusion pump during a strip? We’ve never done it to avoid damaging the diff pump but the only other thing I could think of would be running the diff pump during strip…this would probably get us down to 100-150 microns during strip which is closer to the 80-100 we usually run at. The diff pump is on the second stage and we don’t normally see a ton of terps over there

Sounds like the pump can’t keep up with the larger area of a 10” evaporator.

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Unlikely, the missing cold trap is the problem here.

May very well be the case. I’m just pointing out that for two equally long evaporators, the area almost triples, (5/3)^2 ~ 2.77

Oops, my bad. The area increases by 67%. No squaring involved in finding cylinder area.

Just an update here to add as much data as possible. Our normal potency with this material is between 95-96%d9 final product. Running in the 10 the material was the same color and slightly lower potency. Just came back at 93.5% d9.

We also produced about 10% less distillate than usual. So not ideal anyone with any other suggestions besides the Ln2 trap would be appreciated as that’s going to be custom and may take some time.

Would a more powerful vac be enough? We currently pull with an edwards30

A liquid nitrogen cold trap protects the pump, it doesn’t necessarily improve your vacuum. The pump still will have to contend with the volatiles in the evaporator.

What if you ran the material twice, a first pass just to get the higher volatility register out, maybe not run at full vacuum. Then on the second pass, you should expect improved vacuum behavior.

Still, though, you are evaporating more cannabinoids per unit time with the 10” wiper than with the 6” wiper, and your pump may not be up to the task. Maybe try feeding the WFE a little slower to see if things improve, basically running the 10” under 6” conditions. Only for troubleshooting, of course, otherwise it would defeat the upgrade of evaporator area.

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I have a question on the cold trap, what size liquid nitrogen trap did you use, we are having the same issue.

was 100% the problem. Got the new cold trap and we are hitting perfect torr with 5L/hour output and perfect quality.

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We needed to go fast so we compromised a little and went with a 6” , we wanted an 8 mainly just for the larger reservoir size so we wouldn’t have to fill as often. but they only had the 6 in stock

We ended up with a 6” trap with KF50 flanges. Our primary cold trap was an ISO63 flange so we got a couple ISO/KF adapters. It performs flawlessly. We still might upgrade to an 8” just to have to fill it less though but we are very happy

made some additional tweaks and we now run at .001mtorr. 5/L an hour output. Single pass averaging 96% d9

Very happy with the purchase and the trap was def the issue. Honestly don’t understand how people run without one.

Garb pump, go e2m40/80