Einstein's Refrigerator - Cooling Agent & Size Matter?

[whocouldshebe]

Einstein's Refrigerator - Cooling Agent & Size Matter??

I'm looking at Einstein's patent #1,781,541 for a closed non-mechanical refrigeration unit approved Nov. 11, 1930, filed Dec. 16, 1927.

http://www.fourmilab.ch/etexts/einstein/uspat1781541/www/"

I'd like to power it with the solar heat from 1 or 2 of my mirror covered mini satellite dish(s) commonly called a "Death Ray" on the youtube videos.

The question I have is about the size and cooling agent refrigerants. First of all I don't want to build a big one, and I don't want it do be under 100's of PSI either, nor do I want to use dangerous Ammonia nor butane gas. Are there more modern possibly even better alternatives? Does size matter, can I scale it down as much as I want and it still make ice?

I'd like to use a little Propane Gas instead of Butane, since we all have it readily available in gas form, and it isn't considered dangerous.

I'd also like to replace the Ammonia with Methyl Alcohol (vehicle anti-freeze) since it is very cheap and easy to get at any auto store.

Finally, I want to make it really small, I mean tiny, like 1 foot wide by 1 foot tall, using just a few ounces of fluid, out of ice maker tubing (or fish tank tubes) with fish tank aerators for distributor heads, copper tubing and aluminum cans (only where it needs to be heated), PVC hot/cold pipes for external tubes surrounding smaller tubes, using solar powered computer heat sinks and fans where heat condensers and/or heat ex-changers are needed.

Will this be possible, or do I have to make it really big with all the dangerous uncommon ingredients to get it work?

Thanks!

 

[whocouldshebe]

No replies yet, am I in the wrong forum or something? This is pretty old stuff, somebody's got to know? I've got this project planned for October, maybe I'll just build it and see if it works?

 

[whocouldshebe]

I'm thinking of maybe even using the evaporation of Carbon Dioxide by dropping a small piece of 'Dry Ice' into water the water filled condenser on the left then using propane, ethanol, methanol, or sulfur dioxide on on the right.

Or should I just put water into the left, shut if off, then pour ammonia cleaning solution in on the right, then afterwards add propane, ethanol, methanol again on the right and shut the valve there leaving it under pressure? (then heat on the left)

There's this site that lists solubility of gases in water but I don't understand what the best options are:
http://www.engineeringtoolbox.com/gases-solubility-water-d_1148.html"
In seems that compressed carbon dioxide alone would make the entire system colder than room temperature own it's own...
I also have a fuel cell so Hydrogen is another option that I could easily use as a gas...

 

[Curl]

These gasses won't work well, what you need is a liquid/gas type where the liquid greatly reduces the vapor pressure when it allowed to mix. If I recall correctly, that is how Einstein/Szilard made their refrigerator.

This is more of a mixed-engineering question which is why nobody answers. Home-made projects don't get a lot of input because we're not there to see what you're doing so we can't really answer from the little information you gave; i.e. it is an ill-posed question.

 

[whocouldshebe]

Einstein used Ammonia, Butane Gas, and Water only. It is noted in the copyright. All I'm doing is asking for better safer chemicals to replace these. I would think that basically any chemical engineer could answer these questions with all the safe modern evaporation coolant alternatives we have available today...

 

[Disinterred]

Andrew Delano already made this exact fridge in 1998, check out his papers at: http://www.me.gatech.edu/energy/students/andy.htm. They should answer some of your questions.