Freeze drier

Hot plate?

 

Damn! Pouring over reference material and not getting much else done..
@azrancher is correct about R-12. However it is no longer used anyways.. Need to consider one of the refrigerants that will boil at a lower temp. like R-507.. It requires a higher pressure and possibly a two stage refrigerant pump.. The types of pumps used in the home freezers will not supply the needed higher pump pressures. The old commercial freezers used propane or ammonia as the refrigerants and required large pumps. The question that needs answered is what can be salvaged at low cost to provide adequate refrigerant pressures. This also has applications after SHTF.. The advent of mechanical refrigeration greatly improved the abilities to prolong the harvest of food goods. Freeze drying is just a small part of keeping your food storage viable..

 

This could be the solution to running moisture through the vacuum pump.
Vacuum Pump - AC Vacuum Pump w/ R134A & R12 Connectors
Granted, you need a heck of an air compressor to run it, but the vacuum pump it's self has no moving parts, and requires no lubrication. I have the previous version of this, and it will pull 27.5 to 28" if you have the air to run it.

 

Already considered those as I have a Mastercool version for AC work. We need in the range of -29.98 inHg to freeze dry. 28" doesn't even get us below the triple point which we must go below to get into sublimation. Thanks for thinking though.

 

My dad and sister bought a harvest right for $4,000.00 whole family uses it, she said cost about $2 a day in electricity. But well worth it for storing food.