I’m running fresh frozen material in a CLS and I normally use a chiller with a dry ice bucket and columns with dry ice. I’ve never had an issue with moisture or water getting into my oil.
I recently tried a few runs with just the chiller cooling the solvent and did not use any dry ice in the runs. It seems that I’m getting water or moisture in the pour and not sure exactly why?
Sounds like your material might be thawing out just enough.
I should mention I also did a run of dry indoor trim and still had moisture come through.
Do you run a molecular sieve on your recovery path?
Yes I do
I guess before I write that off, do you ever have frozen masses in your solvent tank?
Are you using a recovery pot submerged in water with a splatter platter?
No its a jacketed pot i use with a circulator.
I’m thinking maybe you haven’t recharged your Mol sieve lately.
i changed it right before i tried it with just the chiller.
Also, was this run before or after the fresh frozen runs that presented issues?
i ran the trim after the fresh frozen runs. i did 4 fresh frozen runs. i changed the mol sieve before the first run and had previously only done a couple runs with the sieve before.
another thing i changed was i had a coil running through my chiller before i wasnt using. iu wasnt running any coolant through it i only ran the coolant on the outside of the tank in the part where it is jacketed. now i run coolant through the coil that is goes through the middle of the solvent tank.
It sounds like you ended up with water in your solvent, or system, during the fresh frozen runs resulting in a fouled cured run.
I would assume the water came from thawing material, either packed too slow, or placed in a room temperature column, or washed with cold, but not exceptionally cold solvent, or a combination of any of the above.
The mol sieve should’ve remediated water in the solvent upon recovery, but wouldn’t remove water from the interiors of the column, or any other line or vessel between the column and the recovery path, to include your collection
Also, even if your solvent was very cold before the first run if you rushed into the second run your solvent may not have been given sufficient time to reach those low temperatures again, meaning if you stacked the collection of those fresh frozen runs you could’ve contaminated the second run with the first, which would still be what contaminated the cured run unless you’d cleaned the entire system between them, even with just a blank run.
Coil built into your collection?
built into the solvent tank
Check all gaskets, send all solvent to collection (with no heat) spray soapy water over all fittings and pressurize the tank and inspect, do that same for the collection and material , if you chilling ur solvent with a chiller and got a leak the moisture gonna travel to the coldest part, also run some alumnia 150 to battle moisture
Look into ur solvent tank if u see frost on the internal coil you have a problem
I still think it’s what I mentioned previously, but could there be a leak on one of the welds or in the length of the coil?
I also don’t think it’s getting to your solvent tank. I think it was left in the column more than likely, but I’m really just guessing without seeing your system.
And sometimes
U r gonna have to dump the solvent tank and clean and put some new new in
What happens when you don’t dump all your solvent periodically?
I’ve known labs that run for more than a year without completely dumping their solvent and never seemed to encounter any issues.
I mean you can try and battle it,
But when running a production base lab, and u see financially it could be more profitable to replenish the solvent tank, than spinning the wheel of luck and hoping the next run Gucci , and possibly having to do another redissolve
