My partner and I have been shopping around for immersion chillers (trying to eliminate dry ice from the lab for obvious financial reasons). I read somewhere that using a -100C chiller can cause condensation of oxygen and create an explosive environment. Well, now I can’t seem to find where I read that and have found a very reasonably priced -100C chiller… Everything I’ve found through google is saying that using liquid nitrogen in your cold trap can cause this to happen. However, liquid nitrogen is said to maintain a temperature of -210C to -196C. This is obviously much lower than the chiller will go. Does anyone have any experience with these -100C units? Is it dangerous to use one of these? My number one priority is always to keep my staff safe. Any insight, as always, is much appreciated.
It’s a warning on Lab Society’s page. Not sure where exactly though.
Edit: Found it. Under “Vacuum/Cold Trap”
https://labsociety.com/lab-equipment/g2-short-path-distillation-kit/
Oxygen isn’t flammable itself. The bigger risk is probably abrupt pressure changes from oxygen condensing to a liquid and then evaporating very quickly. I’m pretty sure I have observed oxygen sublimating from a LN2 cold trap with no thermal load on it.
The liquid nitrogen will freeze oxygen from the atmosphere and it is described as a bluish liquid. The danger then is extreme because liquid oxygen present will make anything at all that is flammable potentially explosive. Mixing volitile terpenes with liquid oxygen is like mixing up space shuttle fuel. It is hard to imagine an immersion chiller posing this threat.
Oxygen boils at -183°C (I think?) according to the internet so the chance of your immersion chiller posing this threat is zero. It is my understanding that only a LN2 vapor trap can cause this.