Hey guys. Had a question about my short path… the last few runs I’ve been doing, my pump oil has become very dirty very fast.
I’m using a mechanical cold trap, which brings the vapor through 2 glass catchers in -34 iso.
The last few runs I’ve started with clean oil after a quick flush and refill, but fairly quickly I can see my pump oil become mega dirty. These last few runs particularly are a little extra nasty as I’m testing some already ran material with my etho setup to see if there Was anything left in the biomass, since the person running the hydrocarbon cls wasn’t the most efficient. I can see vapor making it thru both cold trap tubes and the pump is just eating it up. I suspect there may be a fair amount of etho in the crude. Is this why people use cheaper pumps to eat up the heads and volatiles? Just wondering if there’s something I’m doing super wrong lol
Included are a few pics of my pump and cold trap set up as well as my filthy pump oil shortly after starting a run with fresh oil.
those ai mechanical traps are poor at catching terps
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Is it that it isn’t cold enough or what? Is this semi normal ? I’ve read plenty of people say they change their oil on every run. So is this kind of expected? It’s just crazy how fast it goes from clear new oil to milk chunk
There not even close to cold enough, i run 2-3 traps for 1st pass last trap is at -90+ and you need a roughing pump. Those welch have a very small reservoir so it gets contaminated fast
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Its always reccomend to change the oil after every use.
My oil still looks decent to new after 1x 900ml crude (600ml disty) run.
I just use a basic glasd dry ice cold (only) trap
Yep, you need a colder trap. Stainless or glass for dry ice unless you are able to get a probe chiller. You can use crushed dry ice or a slurry, but if you use a slurry you should use acetone or 99% iso to get cold enough. Warning about iso it will boil violently if misused and splash everywhere.
Also no reason to not keep using your current trap. Just put the second one between the ai trap and your pump. I run 2 dry ice traps. The second trap does wonders for both vac depth and pump life.
It seems like those traps are too small, if you have a larger volume trap the vapors will have more time to condense.You may want to consider a desiccant trap as well, it looks like predominately terpenes and water in your pump.
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What would be the best options for the desiccant trap? I had been looking to add one but even after asking here on the forum haven’t seen much chatter
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I’m thinking that not doing a full decarb, and using material that I believe was not handled 100% correctly thru extraction led to this overload of nasties. It was never that bad and has gotten better with subsequent runs of better stuff.
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If you put dry ice and alcohol in your mech trap reservoir you’ll achieve -78c. -38(assuming celsius?) but either way not cold enough for single trap IMO. Lab society now makes a trap that will fit your AI which is all stainless and allows you to keep kf25 fittings throughout your system. Just something you may wanna scope. I use that trap with a -112F AI mech trap and it works wonders 
We are putting these onto our vacuum carts, they help with back streaming oil and moisture in the foreline.
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Totally agree the last trap i have inline os -90c and the ones before that are a di slurry, with a liberg condenser to cool everything before the traps
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