Hi all, There was a thread here a week or so back (that I can no longer find) about building a liquid oxygen generator which discussed the problems of a non lubricated compressor and the issues with very high pressure hot O2.
I have just remembered a lab demo of a potentially MUCH safer way to get there: LN2 has a LOWER boiling point then LO2 so it should be possible to build a liquid nitrogen plant then pass O2 thru the liquid nitrogen to liquify it (at atmospheric pressure).
The nitrogen compressor is of course a much easier proposition as it can be lubricated, use rings, use metals that are flammable in high pressure O2.... Or you could just buy a dewar and purchase LN2 (it is really very cheap) for your plant.
The boiloff from the cryogenic heat exchanger (at the BP of N2) can of be used to cool the high pressure N2 or low pressure feed O2 to provide energy recovery.
Please think thru the all safety implications before trying any of this, liquid oxygen is a killer.
Just a thought.
Regards, Dan.