Has anyone noticed their CRC column/spool get a bit hot during initial stage(s) of a run?
I run BHO for shatter and recently started noticing my CRC spool (loaded with CR41+ActivatedAlumina) getting almost hot to touch shortly after I open the solvent tank valve feeding the main column. My CRC sits atop my collection pot and is fed via hose from the biomass column, with that path being left opened prior to feeding butane. (The CRC spool is the only vessel in the transmission path that is not jacketed and chilled to -40c.) As soon as the sub -40c butane starts filling the biomass column I notice the CRC spool rapidly heats up (from ambient temps, ~20c up to +40c) and seems to cause a backstop in gas pressure causing the CRC spool to slowly to fill up with cold solute. Having my collection pot (jacketed) chilled condenses the (hot) gas coming through and the CRC spool gradually cools down as the chilled solvent moves down the CRC spool.
I thought at first this was due to the ambient temp of the media and CRC spool boiling the incoming chilled solute resulting in rapid gas expansion and backpressure translating into heat (friction). Though this still seems to me the likely mechanism at play with regards to the unusual heating up, after reading this thread (t5-t41-and-crystal-resistance) I am left wondering if there is more at play here than just phase change via temp differential causing pressure-based heat (i.e. could it be a redox/oxidation occurring, or an exothermic reaction from bits of water mixing with weak bases). If so then I would have to adjust my CRC stack to compensate for such interactions. Currently I have CR41 on top of filter papers with a mesh screen gasket and cotton ball filling and more filter paper on a filter plate to catch fines, and Activated Alumina stacked atop the CR41 to catch water/lipids/waxes. Moving the AA below the CR41 was what I thought would fix this…
BUT…Thinking more on it now I am convinced its just the temp-differential phase change (liquid-gas) along with constant head pressure (N2 assist to be slightly above 0 psi) causing a temporary pocket of pressure which translates to heat (from compression/friction). Yeah, even though this phenomenon doesn’t significantly slow down the run I still think I should get a jacketed CRC spool which will avoid this circumstance and should improve run time duration for the solute to accumulate in the collection pot. That or go back to freezing the CRC spool prior to runs.
My main concern with this was the possibility of the temperature jump adversely affecting the output quality since the CR41 (and other CR variants) works best at sub -10c temperatures. Reading suggestions in here though make me question my stance on cold runs being best for CRC media.
Perhaps I am overthinking this … but is it not ideal for the solute path to be at an even temperature (whether chilled or not)?