Slashdot Mirror
Thermoacoustic Cooler Means Green-Friendly Icecream
MuddyRiverDoc writes "National Public Radio aired a story describing ice cream
manufacturer Ben & Jerry's sponsored
development of a thermoacoustic refrigeration technology, which uses helium gas
subjected to ultra-loud 173 db sound to chill an ice cream cooler. The NPR interview and
pictures of the Penn State researchers who did the development is
available. There is also a brief description of the technique at the Penn State Live site and at the BBC, and an
over-cute Ben & Jerry's broadband presentation, Sounds Cool!, that
does however provide a useful diagram. Thermoacoustic refrigeration has been a focus of research
for more than a decade at Purdue
and elsewhere,
and has reportedly flown on the Space Shuttle, but this prototype is reportedly
the first that demonstrates the size, efficiency, and quiet operation that
promises successful commercial introduction. Cool Sound Industries,
Inc. is reportedly exclusively licensed for this thermoacoustic technology."
So does this mean that noisy, drunken parties will be cooler than quiet, staid cocktail parties?
Great minds think alike; fools seldom differ.
Ever see people driving down the street with their radio so loud their car buzzes. They're pretty cool right?
Need a Catering Connection
I really miss a microwave fridge in my kitchen
Now I can buy that new kick-ass sound system without worrying about that new fridge my wife has been hounding me about and not feel guilty!
It's hard enough to remember my opinions, never mind the reasons for them..
I heard this interview on the radio. Apparently the process doesn't save any energy. It doesn't use ozone depleting chemicals though. Unless it ends up being much less expensive to manufacture I doubt it will go anywhere.
"God fights on the side with the best artillery." - Napoleon, Marshal of France - speaking truth to power
Out of curiosity, is there a reason why peltier coolers haven't been more main stream? I even have a small cooler that uses one, but it seems the idea of making it into larger appliances is something not which of thought.
Bel, the mostly sane.. "Of course I can't see anything! I'm standing on the shoulders of idiots." -- Me
When Unilever bought them out, most of us (shareholders, that is) assumed B&J's would get folded into the corporate machine and lose some of its identity. It's good to see that they've sort of remained a seperate entity that just happens to be owned by a corporate giant.
Well, here's yet another link that says..
But from the outside, it's no noisier than your typical icebox. The noise generated by the Penn State fridge can only be reached when the gas is under tremendous amounts of pressure -- 10 atmospheres worth. If the gas escapes, the pressure dissipates and the sound dies down.
I'm too lazy to RTFA and the writeup was full of links but short on information.
Can someone tell me what this is all about? Is there a chance I can get indignant and rant about something I have neither the time nor patience to understand?
"Yo B, turn that sh*t down..."
"Naw man, it's cool...just makin' ice cream"
"Word"
Wise men say, "Forgiveness is divine, but never pay full price for late pizza."
So they've taken "We all scream for ice cream!" literally?
Inside the canister there's 198 Decibels going on... That would shatter your ear drums and make your eyes bleed (possibly) pretty quick I understand...
Outside the container all your hear is a regular humming noise at one frequency...
If you ignore the other uses of a tool, does that make the tool less useful, or you less useful?
Hi, I live in Canada and I've always wondered why we didn't have a fridge that would take advantage of the outside temperature ? I mean, when it gets down to -20s celcius and you spend a lot of energy heating your house to +20 celcius, then you spend some more energy to cool down the fridge inside the house (although it actually participates in heating up your house), it sounds kind of ridiculous, don't you think ? Is there a particular reason for this ? Maybe it wouldn't be of much use for anyone but canadians, russians, norvegian and the like, but still... I've always known there was a link between noise and temperature... After all, my fridge sure is noisy !
IANWYTIA (I Am Not Who You Think I Am)
Barry White.. cool
Cindy Lauper.. not cool.
- these are not the droids you are looking for -
173dB is quiet? Was your previous job in the PR department of a CPU fan manufacturer?
"'I pass the test,' she said. 'I will diminish, and go into the West, and remain Galadriel.'"
- JRR Tolkien.
This may be the first technology where yelling at a piece of broken equipment really loud makes it work?
toresbe
"thermoacoustic refrigeration technology, which uses helium gas subjected to ultra-loud 173 db sound."
I know...RTFA, but...I did read the FA. Problem is I must have read the wrong one (so many links here.)
Whatever they use to keep the 173db sound locked inside the box, I want. I'll use it to line my appartment walls, as I'm tired of hearing the latest crap..err...latest top 40 hit being blasted by my neighbor's juvenile deliq..err...teenager.
There are lies, damned lies, and statistics.
A class I was taking last semester was being taught by a retired NASA program manager who mentioned the helium scarcity. Most of the world's helium is "mined" in Texas, so if this were handled correctly it could lead to quite the litte technology monopoly. OTOH, if helium were to become more scarce on earth I pretty sure someone would find an alternative source.
"God fights on the side with the best artillery." - Napoleon, Marshal of France - speaking truth to power
Reported maximums (research-only included) in terms of Carnot efficiency:
Stirling-cycle (phase-change): ~50%
Peltier junction (solid state): ~10%
Thermoacoustics (standing wave in gas): ~40%
Using a 'speaker fridge' now would be quite wasteful in terms of efficiency, although researchers believe that they can surpass the old CFC-type compressors soon.
The question that comes to my mind, though, is why the focus on the cooling itself. For a non-emissive object like ice cream, better energy conservation may be more easily achieved through better insulation. How about investing in cheaper silica aerogel, hippies? This stuff is virtually as light as air, essentially made of sand, almost as insulative as pure vacuum, and fairly strong. Having a cooling engine without any ozone-depleting chemicals is great, but it's kind of silly if your freezers still have interior styrofoam lining.
First off, the 190db figure is the sound level INSIDE the unit. Acording to the reporter, the sound level outside the unit was no louder then a standard cooling unit.
From the description of given, the tech sounds interesting. They use a powerfull speaker to create areas of high and low preassure in the chamber. In the areas of low preassure they place tubes which run to the cold case. In the areas of high pressure they place tubes which run to an external heat exchanger to vent the waste heat.
I can definately see this technology comeing into widespread use in the future, as stricter enviromental controls continue to restrict conventional refirgerants. I also wonder how well it would work in an automotive setting, where the high level of vibration makes coolant loss more of an issue.
- How eco-friendly is the helium extraction process? Off the top of my head I believe it's fine, but are there any hidden eco-hostile effects in its production? Probably still far better than the method it replaces.
- Have they experimented with different sound sources for the 173dB? Playing Barry White could produce seriousness smoothness...
- Will they equip the Refrigerator Gnome that controls the internal light with OSHA-approved protective headphones, or will a generation of the little critters be doomed to deafness? (Don't laugh, I saw one of them in my 'fridge once after a Dead concert.)
I always liked these - not too hard to make, but also not as effecient as other methodes. Apply compressed air, tube gets hot on one end and cold on the other.
try { do() || do_not(); } catch (JediException err) { yoda(err); }
The reason you don't have ammonia in your car and home is that exposure to the chemical in concentrations above 300ppm poses health risk. 30 minutes of exposure above 1720ppm can cause death and 5,000ppm is rapidly fatal. It should never be used in a run-to-failure, zero maintenance system like your kitchen fridge or AC unit.
Simple people talk of people, better people talk of events, great people talk of ideas.
Themoacoustic coolers can probably be produced with a much higher mean time between failure as well. Fewer moving parts. I assume they could make a long-life speaker cone and make it replacable with a "slide out, slide in, recharge gas" type fix.
The end result is fewer fridges go to landfills beause they broke.
Even if the average lifetime of the fridge can be raised by a few percent, that's significant reduction in appliance-garbage.
The key difference between helium and argon is density. Helium is (obviously) lighter than air, and when released, floats to the top of the atmosphere. Presumably some evaporates into interplanetary space, given the energetic environment, there. Argon is denser than air, so it will tend to stay in the lower atmosphere.
Both are fossils of creation, but helium is also generated by alpha decay of radioactives inside the Earth. (Alpha decay particle steals two electrons from an unsuspecting nearby atom and presto, helium.)
If there were enough desire for helium, it might be possible to scoop it from the upper atmosphere. There has been talk of space planes running an oxygen liqufaction cycle for an 'air-breathing rocket'. If we can actually do that, we're halfway to mining helium. Helium would be part of the stuff that *didn't* liquify on the first part of the cycle.
The living have better things to do than to continue hating the dead.
Apparently thermoacoustic refrigeration works better in orbit because in space, no-one can hear ice cream.
1: invade Iraq.
2: Steal the Oil
The US did not invade Iraq to steal oil, for a number of very obvious reasons:
Please...It's getting ridiculous that so many people still believe that this is a war for oil when the numbers didn't add up before the war and still don't add up after the war...