Sciencemadness Discussion Board

Fridge pump for refrigeration

Pumukli - 13-3-2016 at 12:03

Yes, it is fridge pump question, but it deals with the ability to refrigerate rather than making vacuum, so I think it is legit here. :-)

One day I was pondering what would happen if I got a fridge pump, put a copper coil on one side (compressor side) and submerged this coil in basically a bucket of cold water. Then another similar coil would be put on the expansion side and submerged this (cold) coil in some sort of heat transfer liquid (longer chain alcohol maybe) in an insulated bucket (Dewar-bucket). Then filled the pump with the appropriate refrigerant and turned it on.
(Basically I was thinking about making an "active" or "continuous" cooler to use instead of salt-ice or other exotic cooling mixtures.)

Questions: 1, could it work? 2, if yes, then what would be the lowest achievable temperature on the cold side (approximately)?

S.C. Wack - 13-3-2016 at 12:30

You'd need a restriction/meter between the hot high pressure and cold low pressure sides. The temperature is the boiling point of the refrigerant, at the pressure found in the evaporator.

The restriction can be and often is as simple as copper capillary tubing.

[Edited on 13-3-2016 by S.C. Wack]

Pumukli - 14-3-2016 at 00:29

Thanks S.C.Wack!

So it seems doable. Now I have to look up refrigerant temp/pressure/boiling point data.