dry-ice freezers

[Argus]

Hmmmmm....

My recollection is that dry ice is solidified CO2 that returns to the gaseous state at atmo pressure by sublimation. Therefore it just needs to be kept in a sealed, insulated container. It will sublimate sufficiently to fill the space in the container to its saturation limit and, losses permitting, it will last for days.

The only use I ever had for it was in the dim and distant past when I worked on big chillers, Centrifugals and the like, that suffered a broken tube.
It was delivered in insulated boxes and I used to keep it in plastic bags in an old domestic chest freezer.
Drying a flooded chiller to a servicable condition was a marathon job.
We used to blow out the worst of the water from the shell with N2, but the real work was the evacuation that could often take weeks. To keep the (expensive) Vacuum pump oil from saturating with water and to save time on ballast mix, we rigged a knock out pot to get rid of the water.
It consisted of a closed steel vessel with an open hollow pot inside it with the CO2 / R11 mix in it.
This was placed in the return pipes to the Vac pump and the moisture laden air/krud mixture would freeze in the pot. Periodically we would melt the frozen ice/krud and throw it away.
You did that until the chiller came through dry. For the last stage of evacuation you could discontinue the dry ice. It took a lot of time and CO2. Never had any other use for it.
If I had to do that job again I would probably construct a small heat exchanger and hermertic compressor, but dry ice was cheap.
In those days you could use R11 like that and stay out of jail. Now, we know better, don't we?
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Honda 70