Making Ice from Sunshine

Before refrigerator was invented, people were making ice. This was using pure mechanical energy. A wooden cylinder like box was used. This had vanes and was mechanically turned for a long time, in doing so the ice was formed on the surface of box. Explaination was when water is heated first upto to 4 degree it will cool down and then only the water temperature raises. When churning takes place water is expanded and heat is released thus making it cool.Hope experts can give better explations.

Sriki:

That process and your explanation make absolutely no sense to me. That would warm the water, not make ice.

It sounds like a cross between a butter churn and the high school lab device that employs paddles moving in an insulated vessel of water to raise its temperature (a kind of mechanical calorimeter), similar to what Joules used:

http://scienceandsociety.co.uk/results.asp?image=10306299

Alhuey23 wrote: "... In spite of the seeming paradox of the statement, [it was] possible to utilize the rays of the sun to make ice".

Think about a paraffin or gas refrigerator/freezer. Heat, compress, heat exchange with environment, decompress, or something like that...

Alhuey23:

I don't know how the steam engine figures in, but the steam passing through a condenser (and liberating heat) can drive an absorptive cooler.

Gas refrigerators and air conditioners use this process, where a gas flame is used, typically in conjunction with water and ammonia.

Many large buildings employ steam to make ice or cold for refrigeration or air conditioning purposes.

A definition of the absorptive process:

http://en.wikipedia.org/wiki/Absorptive_refrigeration

A link to a patent on solar refrigeration:

http://www.google.com/patents?hl=en&lr=&vid=USPAT4100755&id=ImA8AAAAEBAJ&oi=fnd&dq=%22Leonard%22+%22Absorption+refrigeration+system+utilizing+solar+energy%22+

Absorption refrigeration seems to be the answer......Any source of heat can be used so long as the temperature is at least 250 deg.(equivalent to 20 psig steam).

In the late 50's when I was a student. The M E department of the University of Florida was actually doing experimental work to do exactly what you wish to do.........Use solar energy to produce refrigeration, to cool air and MAKE ICE. The absorption cycle using both ammonia and Lithium Bromide was working using flat plate solar collectors.

It seems even today, after a "Google" search there is still not a device that you can buy "off the shelf" to do your solar cooling for you.

If you are really an eco freak and want to do this to prove a point. You could use flat plate solar collectors to pre heat the ammonia or Lithium Bromide solution and then send it to a parabolic concentrator to bring it up to the proper temp for regeneration. The reason this is not done in practice is because Propane gas is still only $2/gal and the solar route will cost a bundle of capital dollars. Better to put the dollars in T-Bills and buy the Propane with the interest. Also there is very little repair work needed for a Propane burner and the tank to hold the Propane.

Harrison McDonald PE, BSME

Try looking at gas-powered adsorption refrigerators as may be found typically in a boat or a caravan, and look at replacing the combustion-based heat source with solar.

A large solar-powered Stirling engine mechanically connected to a smaller Stirling engine running in reverse might also do it...

Mouchout was NOT making refrigeration directly but merely using the solar heat to provide steam for a steam engine to drive a conventional refrigeration system.

Not so much what you say as what you do! Read the details at:

<www.personal.psu.edu/users/k/o/kom109/solarenergyproject.doc >

BTW: How do you/I turn OFF the wide screen and/or horizontal scrolling in XP?

I just made a reference to Mouchout. What I understand he was the first one to notice this potential.

rockwool is highly hydrophilic, by connecting 2 separate containers of water and rockwool respectively, connect both via tube(with valves between them and the tube should have air sucked out). Open the interconnecting valave(s), vacuum causes water to boil off, the vapour is then readily absorbed by rockwool in the second container. The process actually feeds itself as water absorbed by rockwool will be replaced by further boil-off from the first container. Well, the continuos boil-off requires heat input- well, this comes from the water itself-until it freezes!