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:Third World? (Score:1, Interesting)
Easier ways to make ice in electric-poor areas (Score:2, Interesting)
2. Solar cells used to create it and charge batteries at the same time.
Inefficiency is in the eyes of the beholder.
1.000.000 RPM (Score:3, Interesting)
10000000 rpm could be acheivd with mules and huge gears?
To make that "high rate of rotation (over 1,000,000 rpm)." Better use the ice on your legs after.
If you press a gas into a cylinder with a specific angle, it starts to rotate at a very high rpm. Here is the construction [freeserve.co.uk].
Please RTFM first.
I love vortex tubes (Score:1, Interesting)
They take a hell of a lot of air pressure so they are wildly inefficent. It'd make more sense to hook up a generator to whatever energy source you have rather than a compressor. Even if you're running a windmill you could power a good sized freezer for the energy a votex tube would take to operate. They're a lot of fun and have nitch applications but they are mostly a curiousity.
Electricity isn't required for a fridge anyways (Score:1, Interesting)
Your refrigerator doesn't require electricity. All it requires is something to spin the compressor, which includes water wheels, gerbils (a lot, one would suppose) or disembodied spirits (how many fit on the head of a pin again?).
Why use compressed air? One already compresses the refrigerant, so no advantage can be found by using compressed air.
If his goal is to use air instead fo freon for refrigeration, I suggest that he build Stirling engines.
Re:Why not gas absorption? (Score:5, Interesting)
The funny part ? They still work flawlessly, and have not been serviced since at least 1977 ( In know this for a fact as thats when my grandad passed away)
Their electric consumption is actually minimal, running both all month equates to about a 60$ electricity increase. Unreal if you ask me, I kept thinking we were on an electric budget the first summer I fired em up in 20 years as it was way to hot for my grandma without air so I told her I would cover the bill. it never went up....
The beauty is these units will spill the ammonia outsie through the exhaust should the coils ever rupture (I doubt it since they are about 1/8 in thick copper
Re:Hrm. (Score:5, Interesting)
If you build a solar reflector, but only employ it at night the items inside will become cold, and can attain temperatures below freezing.
Doesn't work as well on cloudy nights (you are essentially 'beaming' the heat out into the great heatsink called space) and it has to be well insulated from the environment around it (ground, air, etc).
-Adam
The Frozen Water Trade (Score:2, Interesting)
Re:I read TFA, and... (Score:5, Interesting)
I make ice and keep things cold EVERY time I go camping without electricity. in fact I make a fire to make things cold.
that type of freezer/fridge has been around for decades and are pretty efficient now compared to electric units.
I use maybe 10 pounds of Propane to run my RV fridge for 3 months straight.
I'm all for inventing new ways of doing it, but to "help the poor in africa" is not the way to try out new stuff.
give them a fridge with a coil plate they can build a fire under or will allow an oil lamp burner to keep it running (yes this works) and use that old tech that simply works.
Re:In Soviet America... (Score:2, Interesting)
And in conservative America, everyone likes to pretend that class and race are distinct issues.
Re:The big question is... (Score:3, Interesting)
And on another note there is a method of refrigeration [howstuffworks.com] that does not use any moving parts and works on gas(or anything that will burn I guess). Maybe this can also work with a solar mirror array?
And while you're at it (Score:3, Interesting)
And while you're at it, a solar concentrating mirror (or foil arrangement), without a greenhouse-forming glass layer, pointed at a cloudless night sky, makes ice REALLY well.
The night sky (absent clouds and above the atmosphere) is four degrees absolute - and it's not THAT much warmer from ground level even with the mostly sub-zero greenhouse gas layers floating above. With mirrors or foil to redirect the light/infrared so that the container of water (or coolant) "sees" night sky on all (or most) directions and reasonable shelter from air currents, a container's black-body equilibrium temperature is far below freezing. It heads for that temperature quite quickly if it is painted a dark color.
People have been making ice on calm desert nights using this principle for centuries.
Re:Why not gas absorption? (Score:2, Interesting)
Re:Hrm. (Score:5, Interesting)
You jest, but truth is stranger than fiction...
During the first half of the nineteenth century, an enterprising Boston chap by name of Frederic Tudor made his name - and his fortune -harvesting enormous chunks of ice from frozen lakes in Massachusetts, packing them into sailing ships insulated with sawdust (supplied by the Maine timber-mills), and exporting them around the world. By the time artificial refrigeration marked the end the "frozen water trade" in the mid 1800s, they were sending 100-ton shipments of ice as far afield as the Caribbean and Calcutta.
The whole story is told in Gavin Weightman's The Frozen Water Trade [amazon.com], if you want to know more.
Re:The big question is... (Score:4, Interesting)
If I wanted to make ice in a place like back-woods Hati; I think a solar-collector connected to a couple stirling engines would be the way to go, one engine makes kinetic energy from the solar heat, the second refirgerates form the kinetic input of the first engine; sterling refrigerators are capable of acheiving cryogenic temeratures
Re:In Soviet America... (Score:1, Interesting)
The antidote to bad governement isnt no government but good governement.
Some thing you can do to make your democracy work better:
Eliminate first-past-the-post and winner-takes-all elections and go for a more representative form of democracy. Theres lots of info out there on how to run a fair election, and first-past-the post isnt it.
Aggregate congressional reps into regions with 5 or so reps elected from each region. This will make gerrymandering a region particularily difficult. Create an algorithm for determining electoral regions - something that minimizes wierdly shaped regions would do nicely.
Introduce mandatory voting; 40% voter turnout isnt a democracy.
Eliminate and disempower local governement - there is no need for every butt-fuck town and parish in the US to run its own police force, school system, sewerage plant, tax collection, etc etc.