Can I turn my fridge into a cryocooler ?

[spientist]

Is it possible to somehow lower the minimum temperature of an ordinary fridge to at least as low as the temperature of dry ice ?  If not without modifying it, might it be done by replacing the fridge's liquid from Freon to alcohol, or some other liquid or gas ?

[John Cuthber]

It's a matter of definition.

Is Concorde a modified bicycle?

 

[tuco]

First, you have to lay it down with doors facing upwards. Then open the door and pour in liquid nitrogen  

Interesting question. 

[pavelcherepan]

4 hours ago, spientist said:

Is it possible to somehow lower the minimum temperature of an ordinary fridge to at least as low as the temperature of dry ice ?  If not without modifying it, might it be done by replacing the fridge's liquid from Freon to alcohol, or some other liquid or gas ?

Just as John said, depending on what you would consider acceptable modification. You can add some insulation, a second and maybe third refrigerant cycle in a cascade and change HFC-134a to some other refrigerant with lower boiling temperature.

Edited December 20, 2017 by pavelcherepan

[Endy0816]

Would have to modify almost everything. Only built to work within a temperature range.

Likewise can't swap out refrigerants like that. Even similar ones require almost a total overhaul.

@OP: Now are you actually wanting to store CO2 or to acheive -110 degree temperatures?

[spientist]

15 hours ago, Endy0816 said:

 

@OP: Now are you actually wanting to store CO2 or to acheive -110 degree temperatures?

To make and store dry ice or liquid co2, cheaply, and to easily cut cryo-cooled rubber when it's hardened.

[Endy0816]

9 hours ago, spientist said:

To make and store dry ice or liquid co2, cheaply, and to easily cut cryo-cooled rubber when it's hardened.

Its that cheaply part

A pressurized cylinder would work for storing liquid CO2 and you can get dry ice from the cooling provided by the expansion of the liquid(basically have a CO2 fire extinguisher). May want to price out other options depending on how often you need it. Dry ice machine or buying straight liquid nitrogen(if you don't need it too often).

 

[John Cuthber]

Refrigerators designed to maintain -80C are commercially available for use in laboratories + such. They are not cheap.

If there was a cheap way to do it, then people would do it cheaply + undercut the manufacturers.

 

[HB of CJ]

I believe John answered it and thank you John.  Have you seen the "small" super cold "dry ice cold" lab or industrial freezers?  Physically very large for the super cold space that they provide.  Super insulated.  Heavy wattage use.  All just to chill a very small spot very cold.  Some nicer machine shops employ them to enable certain processes like press fitting.  One part warm, the other very very cold.  Way too cold to keep the beer in.  Also too cold for Vodka.  One good gulp of booze that cold will kill you so fast.  Yikes!