Bigger better??
Upgraded solvent side from chiller cooled injection coil to jacketed solvent tank and from one Haskel to a Corken T91 for recovery.
Seeing lower yields on cured and FF runs.
Previously ran -60C coil injecting room temp gas through it and now running -50C jacketed tank. When injecting through coil you could see chiller temp rise about 15 degrees throughout a slow injection to ensure the solvent got cold while passing through it.
With the Jacketed tank, definitely more prone to injecting faster so may have a slightly shorter soak time in comparison. (Fill and dump)
The Corken is a beast but have had to crank up heating baths in collection to keep evaporation rate high enough and since the pump pulls so hard, higher temps required to keep solvent boil from being pulled too high up in collection. Plus side is now I am able to up the solvent to material ratio.
On familiar material yields dropped from 18% to 13%. Significant.
Too cold now compared to coil temps + shorter soak? Too hot/fast on recovery?
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If the solvent is colder and the soak time is shorter, there’s your yield loss.
If possible keep your evap temps as low as possible
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Thanks - would you say going from a 3:1 solvent to material ratio with a 5 min soak to 6:1 ratio with no soak be the same if not better??
Wishing system had thermocouple to see what temp my solvent actually was going into the vessel after getting chilled from the coil…
Inject through Coil @ -60C with slow flow see temps on chiller rise to -45C after 15lbs injected - what actially was the solvent temp… -40?? 
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It’s hard to say what the temperature will be. You can do some basic heat loss calculations but those are totally dependent on the setup itself.
6:1 ratio is a good number, especially if you aren’t using CRC. Typically people can get decent yields at 6:1 without any soak at all
What hydrocarbon do you use?
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Makes total sense - I am getting some data back now. Been creeping my jacketed tank temps up from -60C initially upward in 5 degree increments and coupled with longer/slower injections and a little longer soak times seeing yields start to creep back up. Still not quite where I was though yet. I think it’s fair to say -60C at the coil was in reality mid -40’s at best inside the vessel onto the material.
With not densely packed and finely ground material in material socks is there anything to the whole Channeling scenario when injecting a fast stream into the material?
Appreciate the intel on the ratios.
On dry I’m running 5 or more to 1 solvent to material.
With fresh frozen running 3.5:1 on wet weights… 
Running 60n-b/20i-b/20n-p
Did you figure things out?
Yeah needed to dial in to find the sweet spot:
Found -55C and longer soak times coupled with increased solvent to material ratio. 3.5:1 minimum and soak of 10 minutes with gas continually washing over socks while transferring to collection/recovering in sequence.
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