Making Ice Without Electricity 608
j-beda writes "Time Magazine is running an article telling us how Dave Williams is trying to make ice for third-world applications using the Hilsch-Ranque vortex-tube effect (first developed in 1930 by G.J. Ranque), where swirling air is split into hot and cold components." The method is horribly inefficient but Williams is hoping it could yield helpful results in areas where electricity is really not an option.
Re:New definition of "moving parts" (Score:5, Informative)
The gas moves into the chamber under pressure. The chamber is shaped to send the gas into a whirling vortex. Then the hot molecules go one way and the cold ones go the other. But I think it takes very high pressures to produce the required speeds.
I read TFA, and... (Score:5, Informative)
What's the big deal? (Score:3, Informative)
1) Flexible solar panels (less efficient but more portable than glass)
2) A handful of Peltiers... they're pretty small
3) A couple of cans of "Great Stuff" spray-in insulation, or cans of A-B component expanding insulation
One of my friends went to Peru to assemble a non-electric solar water purifier, and anything they couldn't carry on their backs on 30-mile-a-day hikes for a week didn't go. Now that's a design constraint!
It doesn't take a genius to figure this one out... (Score:1, Informative)
http://en.wikipedia.org/wiki/Einstein_Refrigerato
No moving parts.
Uses amonia, butane, and water...
Re:Dr. Brown (Score:2, Informative)
He also perfected that machine that made breakfast automatically in the morning which was a mess when he tried it in 1985.
Oh and yeah, a time machine powered by steam but thats the only part of the movie I didn't find plausable
Full article (Score:3, Informative)
http://www.time.com/time/magazine/printout/0,8816
You're not missing much, though -- I'm guessing this one was a sidebar blurb, as it's only two paragraphs anyways.
Reinventing the wheel? (Score:5, Informative)
http://www.madsci.org/posts/archives/nov99/941723
Of course, the large temperature difference between the day and night in the desert it what drives it. That method probably won't work in tropical climates.
-Charles
Re:Dr. Brown (Score:3, Informative)
Article text (Score:2, Informative)
At least that was the idea. Tinkering with heat-transfer equations, Williams tried to determine how much energy it would take to yield a block of ice. "It had been a while since I'd done real math problems. I had to break out the old textbook," says Williams, a product-development consultant with his own firm, Dissigno, in San Francisco. After eons of number crunching, he hit on the right formula and built a prototype. It isn't very efficient; his device uses 35 times as much energy as an electric fridge to make 1 kg of ice. But its simplicity could yield a killer app in Third World villages, where Williams hopes aid groups will distribute his icemaker as an economic-development tool. He aims to field-test it in Haiti later this year. --By Daren Fonda. Reported by Matt Smith/New York
Re:Make or Sell? (Score:1, Informative)
http://www.homepower.com/files/solarice.pdf?searc
The article is a bit dated, so the costs are undoubtedly off, but it's got to be one of the lowest cost solutions for this particular problem.
Physics of Ranque-Hilsch Vortex Tubes (Score:5, Informative)
here is a picture of one (Score:5, Informative)
HERE [google.com]
Re:Why not just make electricity? (Score:5, Informative)
Or, we have found First and Second Prize winners in the "Talk out your ass without knowing anything" game.
If either one of you had bothered to look into this device for even a moment, oh I don't know, maybe here [cockerill.net] for example, you'd know that they aren't spinning anything at a million RPM. It is a device that has no moving parts. Basically, and I'll boil it down for you, you blow in one end and two streams come out, one hotter and one colder. It's the vortex inside that can reach a million RPM.
If you can find a way (and this, I assume, is what he's still working on) to get enough air through it then you can get the cold stream very cold indeed, which is useful.
I've never been to anywhere that qualifies as Third-World, but I assume that simple is better. With no moving parts this is as simple as it gets, if a way can be found to get enough gas through it. Perhaps it's wind, or volcanic gases, or storing composting gas, or simply the hot air generated by your armchair engineering, the point is that he's looking into it to try to help people, and you didn't look into it and are helping no one.
Kerosene refrigerator (Score:4, Informative)
Although we certainly used our fridge for food and ice, it was also very important to refrigerate meds for the clinic in our village.
Re:I read TFA, and... (Score:2, Informative)
Re:Clean water first??? (Score:5, Informative)
1. A freeze/thaw cycle kills many (not all) microorganisms--ice crystals shred cell membranes, and freezing can mangle the protein coat on viruses. A number of tropical parasitic organisms aren't well adapted to the cold, either.
2. You can remove some dissolved chemical contaminants if you don't freeze all the water. As water freezes, the assembly of regular ice crystals tends to force impurities out into the remaining liquid. If you stop after you've frozen four-fifths of the water, then you can throw out that last twenty percent that contains the concentrated contaminants. Ice that forms on bodies of salt water is almost pure water, because the salt is driven into the liquid phase by the freezing process.
Re:In Soviet America... (Score:1, Informative)
Re:Hrm. (Score:5, Informative)
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In September 1999, we placed two funnels out in the evening, with double-bagged jars inside. One jar was on a block of wood and the other was suspended in the funnel using fishing line. The temperature that evening (in Provo, Utah) was 78 F. Using a Radio Shack indoor/outdoor thermometer, a BYU student (Colter Paulson) measured the temperature inside the funnel and outside in the open air. He found that the temperature of the air inside the funnel dropped quickly by about 15 degrees, as its heat was radiated upwards in the clear sky. That night, the minimum outdoor air temperature measured was 47.5 degrees - but the water in both jars had ICE. I invite others to try this, and please let me know if you get ice at 55 or even 60 degrees outside air temperature (minimum at night). A black PVC container may work even better than a black-painted jar, since PVC is a good infrared radiator - these matters are still being studied.
I would like to see the "Funnel Refrigerator" tried in desert climates, especially where freezing temperatures are rarely reached. It should be possible in this way to cheaply make ice for Hutus in Rwanda and for aborigines in Australia, without using any electricity or other modern "tricks." We are in effect bringing some of the cold of space to a little corner on earth. Please let me know how this works for you.
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This is an experiment you can conduct yourself. It may be that without advanced insulation (maybe straw wasn't enough?) one couldn't obtain ice in the desert, but given good modern materials the physics suggests that it would work well.
-Adam
Re:In Soviet America... (Score:5, Informative)
That's not how the system is set up. FEMA had authority to act, but only where specifically requested to act by state government. The governer can call of FEMA for help with any problem state and local responders can't handle, but FEMA can't act except where specific help is requested. What *usually* happens is that the state EMA says "command and control is something we can't handle, please take that over", and FEMA does, allowing them to use their own initiative. This did *not* happen in LA, and still hasn't happened.
Also, using the national guard for policing (which was desperately needed) is outside of FEMA entirely unless the president invokes the insurrection act, which would have been a very scary precedent! The governer must effectively deputize the guardsmen, as there is no martial law in the LA constitution. The governer must also directly request guardsmen from other states (they were offered, bu not requested).
Basically, Blanco refused to give up control to people who actually had a plan. It takes more than just declaring a state of emergency (which is a prerequisite), you also have to *explicitly* relinquish command and control to FEMA if you want them to run the show.
Re:Hrm. (Score:5, Informative)
All other things being equal, if an object is absorbing more infrared heat radiation than it is releasing, then it gains heat. This one of the forms of radiation the sun puts out that heats the earth's surface (though lots of radiation is harmlessly bounced off the atmosphere or converted before it reaches the ground).
Since the clear night sky contributes little radiation to the earth the earth's surface radiates and cools off more quickly than it heats up. By using reflectors one can increase the surface area of the radiation and gain greater cooling, just as solar collectors with reflectors can gain greater energy with the sun shining on them.
-Adam
Wrong Wrong Wrong - read National Response Plan (Score:2, Informative)
"When an incident or potential incident is of such severity, magnitude, and/or complexity that it is considered an Incident of National Significance, the Secretary of Homeland Security initiates actions to prepare for, respond to, and recover from the incident." (NHP, 15)
"The President leads the Nation in responding efficiently and ensuring the necessary resources are applied quickly and effectively to all Incidents of National Significance." (NHP, 15)
"Standard procedures regarding requests for assistance may be expedited, or under extreme circumstances, suspended in the immediate aftermath of an event of catastrophic magnitude." (NRP, 44)
Re:In Soviet America... (Score:2, Informative)
Oh yes, everyone knows that in America only "black" people are poor, and all rich people are "white."
There were times, as a child, when I was sleeping on the floor in a run down house with many other people, that was how I lived. Kids' showers were shared to save on the water bill. Food was as often provided by charity as by purchase. I was lucky to even have a few small toys. Here's the shocker for you....I'm "white." There are plenty of poor "white" people out there, I know, I've seen them, lived among them, been one of them.
And there are a fair number of rich "black" people as well.And no, not all of them in sports
Class and race are different issues. The people who do not see that, who say that they are one...well, they are both racist and ignorant.
Re:In Soviet America... (Score:3, Informative)
well, apparently, yes and no. The state controls the guard, and any national troops deployed report to the guard it would seem. I found this interesting tidbit on nola.com
One way of looking at this was that it was a power-grab by the federal government, but I'm not so sure. Apparently the feds had one reason for requesting this, and Blanco (and her staff) had their own reasons for refusing it.
Re:Adsorption cooling (Score:3, Informative)
You might want to be a little more careful not to contradict yourself when "correcting" somebody.
The total system pressure sets the temperature at which the boiler will have to run to boil the ammonia/water solution - so to use a low grade heat source you would have to run a lower system pressure in order to allow the low grade heat to boil the mix and run the cycle.