Thermoacoustic Cooler Means Green-Friendly Icecream 318
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."
Parties (Score:5, Funny)
Re:Parties (Score:2)
noisy (Score:2, Insightful)
Re:noisy (Score:5, Informative)
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.
Re:noisy (Score:2)
Not at all... (Score:5, Informative)
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...
Re:Not at all... (Score:2)
Err, I guess I won't be getting one of these for my house anytime soon. My "large" server room really needs hearing protection if you're going to stay in there for a few minutes. Farking loud Cisco stuff.
This stuff works (Score:3, Funny)
Re:This stuff works (Score:5, Funny)
It also explains why I yell at those morons to "Chill out!", they just turn the volume up even louder.
What is the ultra-loud 173 dB sound? (Score:2, Funny)
Re: Political Hot Air (Score:2)
Of course, you may happen to like politicians. Your milage may vary.
Microwave Fridge (Score:3, Interesting)
Re:Microwave Fridge (Score:3, Interesting)
to a friend, he dismissed it as impossible... but his mother who happened to be there (and also happens to be a major Physics major) liked the idea and after some years of occassional debate between her and her college professor-type friends, they phoned me to tell me that sound waves would do the trick...
At least now I know I wasnt so crazy after all!
Re:Microwave Fridge (Score:4, Informative)
OTOH, one can't convert thermal energy back into microwaves, so the heat must get out of the food by thermal conduction, which isn't very quick in the usual food substances.
Re:Microwave Fridge (Score:3, Insightful)
Everything with a temperature above absolute zero emits black body radiation, which includes microwaves. See Planck's law of black body radiation [wikipedia.org].
Re:Microwave Fridge (Score:4, Informative)
Unfortunately, there's absolutely no way to move heat from anywhere to a warmer place. When one wants to cool something to a temperature that's lower than the ambient we are in, one must first raise the temperature of the medium we want to cool. In both "classical" refirgerators, where a compressor is used, and in these new thermoacoustic chillers, the means used to raise the temperature is by compressing a gas. The compressed gas becomes warmer than the ambient and radiates heat away, through a heat exchanger. When the gas is expanded its temperature drops. Since we let it radiate heat when it was compressed, this expansion will make it drop its temperature to a point that's lower than the ambient temperature.
Re:thermal energy back into microwaves in 6 steps (Score:4, Insightful)
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...
Re:thermal energy back into microwaves in 6 steps (Score:2)
I'm not sure what you mean by "ground source".
As for oil -- are you asking about the efficiency of burning oil for energy, or are you asking how widesprea
Re:Microwave Fridge (Score:2, Funny)
Great (Score:5, Funny)
Helium (Score:2, Funny)
Same Energy as Freon Systems (Score:5, Informative)
Until high volume is reached... (Score:2, Insightful)
It's also possible that in the drive towards production, the system could be made more efficient. As I understand it, the goal so far has been to get it working. That goal has nothing to do with energy efficiency.
The next goal is or should be ramping up production after long-term testing..
Re:Same Energy as Freon Systems (Score:5, Insightful)
I like watching the recent phenomenon of both wood and plastic products being promoted as "Green Friendly," One, because it's, like, natural, organic, renewable and shit, and the other because, like, it's a recycled resource and doesn't require cutting down any huggable trees and shit ( and I can only surmise the latter have never been to the Newark area. Well known for cracking plants. Very few trees.)
Every product is "Green Friendly," if you know how to write the brochure to make it that way.
KFG
Re:Same Energy as Freon Systems (Score:2)
Re:Same Energy as Freon Systems (Score:2)
Re:Same Energy as Freon Systems (Score:2)
Not only that, gas engines have an optimal efficiency at a certain speed. That is why hybrid cars can be even more efficient that gas cars. because the hybrid can run its engine at a set speed.
Re:Same Energy as Freon Systems (Score:2, Informative)
Present refrigeratio
Re:Same Energy as Freon Systems (Score:3)
I know what you mean; the most extreme examples for me are the oil companies and their "We Love the Earth" commercials.
Adbusters had a parody of a Chevron magazine ad, showing a lynx drinking from a pool of crude oil. The caption: "Do animals get rich from oil? No. People Do."
Re:Same Energy as Freon Systems (Score:5, Interesting)
Re:Same Energy as Freon Systems (Score:2)
I heard that (Score:5, Interesting)
Helium is derived from natural gas (Score:2)
Re:Same Energy as Freon Systems (Score:2, Insightful)
Re:Same Energy as Freon Systems (Score:3, Funny)
Helium and Argon (Score:3, Informative)
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 pre
Re:Same Energy as Freon Systems (Score:2)
Re:Same Energy as Freon Systems (Score:3, Informative)
The drop-in substitution would have saved hundreds of tons of equipment that was otherwise scrapped.
I am talking about refrigerants that are a mixture of Propane and Butane. The thermodynamic properties of these mixtures are better than that of Freon. The gases are very inexpensive and relatively harmless to ingest, and can be disposed of by using them to coo
Re:Same Energy as Freon Systems (Score:2)
Re:Same Energy as Freon Systems (Score:2)
This trend to use "omg think of teh childrens!!!!11!!1one!" to suffo
Re:Same Energy as Freon Systems (Score:3, Informative)
The stuff they wanted to use for refrigerants is not the same stuff you light u
Peltier cooler? (Score:5, Interesting)
Re:Peltier cooler? (Score:5, Informative)
Re:Peltier cooler? (Score:5, Informative)
Re:Peltier cooler? (Score:2, Insightful)
Re:Peltier cooler? (Score:3, Interesting)
Of course, I do find it funny that we allow our homes to be built on radon sites, but would prevent Tritium from being used on watch dials. But that was a total knee jerk reaction.
From what I have heard, Boeing is getting ready to use them as is the military. In many ways they make a lot more sense as no mechanical parts. Pretty much means no future repairs or re-filling.
Re:Peltier cooler? (Score:2)
Re:Peltier cooler? (Score:2)
Re:Peltier cooler? (Score:2)
It sounds great, but I'm still waiting on Duke Nukem. Let me know when they're closer to a commercial release.
Re:Peltier cooler? (Score:2)
I think you mean that refrigration is 1300 %..
That's what the EER means on an air conditioner..
The machine with an EER of 13 moves 13 times as much heat as it uses in electricity.
Uh no. (Score:2)
Re:Peltier cooler? (Score:3, Informative)
Basically, they put a gap (of air or other gas) which acts as an insulator between the hot and cold side of the peltier which they somehow get the electrons to tunnel over. This keeps the hot and cold sides completely seperated, which is the real efficiency issue with current peltiers.
Re:Peltier cooler? (Score:4, Informative)
I'm amazed B&J's still operates semi-autonomou (Score:5, Insightful)
Re:I'm amazed B&J's still operates semi-autono (Score:2)
Re:I'm amazed B&J's still operates semi-autono (Score:3, Interesting)
And its probably good marketing . . . keeps the "socially concious" brand reputation.
not 173db (Score:2)
Re:not 173db (Score:2)
Summary please! (Score:3, Funny)
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?
Apparent Contraditions (Score:2, Funny)
If 173 dB is quiet for you, I'd hate to be around when you throw a rock concert! Liquified bones are not my idea of a good time!
And did anyone read that as
the Penn State researchers who died in the development
? I must need a couple more hours sleep...
8-PP
Re:Apparent Contraditions (Score:3, Informative)
RTFA
What if Master P really was the Ice Cream Man? (Score:5, Funny)
"Naw man, it's cool...just makin' ice cream"
"Word"
Oh no (Score:5, Funny)
Re:Bad News . . . (Score:2)
Or even better, put it on the set of Jerry Springer. That way, the audience can call people "frigid bitches" and be serious for once.
Quiet operation!?! (Score:2)
Question (Score:5, Insightful)
Re:Question (Score:4, Insightful)
I've lived in Iowa, and wondered that too. You could, I suppose, attach your fridge directly to the wall, and then simply connect a duct to the outside temperature. Here's some thoughts why that wouldn't work:
It does seem like each of these issues are surmountable with clever tech. Of course, there isn't anything stopping you from keeping your freezer on the porch and turning it off during the winter.
Re:Question (Score:3, Interesting)
Re:Question (Score:3, Informative)
A fridge isn't that efficient in cooling, but it is very efficient in generating heat. Basic physics/thermodynamics.
Like many other devices most of the energy ends up as heat, very little escapes the room/house as light or other forms of energy. In fact a fridge pumps the heat from stuff inside it.
A heatpump can actually be more efficient at heating than a pure 100% heater. This is achieved by pumping the heat from somewhe
and that explains.. (Score:3, Funny)
Cindy Lauper.. not cool.
"Quiet operation"? (Score:5, Funny)
Whohooo...! (Score:3, Funny)
Argggh... Flash required.. . (Score:2)
Depending on efficiency, it could be used for home and car A/C and regular freezers..
It would appear easier to repair and maintain, at least from the one still shot i get to view..
"quiet operation"? (Score:4, Insightful)
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.
Won't work.. (Score:3, Informative)
Refrigeration efficiencies compared (Score:4, Informative)
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.
What's the problem GreenFreeze? (Score:3, Interesting)
Unless they expect this to be cheaper/ more efficient, I can't understand why they would finance such research- except as publicity.
Heard this on NPR yesterday (Score:4, Informative)
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.
Three Observations (Score:5, Funny)
- 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.)
Re:Three Observations (Score:2, Informative)
The Hilsch Vortex Tube (Score:5, Informative)
So you're saying.... (Score:2, Funny)
Ice cream plants are already enviromentally safe (Score:5, Interesting)
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.
Re:Ice cream plants are already enviromentally saf (Score:4, Interesting)
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.
Re:Ice cream plants are already enviromentally saf (Score:3, Insightful)
But once the ammonia dissaptes into the atmosphere there is no lasting, negative effect. This cannot be said of HFCs and CFCs. Heck, this probably can't be said for most of the chemicals under your sink or in your auto. Farmers plow thousands of pounds of ammonia into the ground every year. Thats what I meant about environmentally safe.
With respect to the rail car, with ammonia you will think yo
Finally! (Score:2)
A use for '80s hair metal bands, at last.
what happens if the container cracks? (Score:2)
Re:what happens if the container cracks? (Score:2)
Answered here [slashdot.org].
refrigerant gases (Score:3, Informative)
My new fridge {purchased in a hurry after a defrosting accident last year involving a chisel, the evaporator and a faceful of evil-smelling chemicals} uses iso-butane -- cigarette lighter and camping stove fuel -- as its refrigerant. It's sealed in the pipes, so there is no danger of an explosion. Even if the pipes do start leaking, the thermostat won't be satisfied -- no matter how long the motor runs {trying to cool down the sensor} it won't get anywhere because there is no pressure, so no cooling
Space shuttle (Score:4, Funny)
Apparently thermoacoustic refrigeration works better in orbit because in space, no-one can hear ice cream.
Re:Hmm.. (Score:2, Funny)
Re:Dangerous (Score:2, Informative)
Re:Dangerous (Score:2)
Non-toxic doesn't mean it can't kill you. I was ripping apart a freezer back in my youth and cut one of the tubes on the low-side of the compressor. 15 years later I still do not have feeling in the tip of my left ring finger.
So I am quite positive that if you inhaled enough freon you'd either die of shock or asphyxiation. Or both. :-)
freon huffing (Score:2)
I seem to remember some old 1940s era promotional movies showing the inventor of freon inhaling it to show its non-toxicity also.
Re:Dangerous (Score:2)
Probably not. The 173 dB is a measure of the sound pressure. Pressure is force divided by area - in this case, it's a force generated by a transducer over the limited area inside the device. If the enclosure breaks, the area goes to infinity, the sound pressure is significantly reduced.
Re:Why use acoustics? Why not a mechanical diaphra (Score:2)
A loudspeaker is a simple mechanical (well, electro-mechanical) device!
.Re:Green Friendly? (Score:2)
Re:Thermoacoustic cooling for airconditioning? (Score:2)
The Ben & Jerry's Flash presentation notes that the thermoacoustic cooling process they developed was "efficient." I'm not real familiar with their process (other than what's presented in the linked articles), but I do know that loudspeakers are generally very inefficient - a very "efficient" loudspeaker may translate 1% of an electric watt into an acoustic watt. The rest of the energy goes to heating the voice coil.
Now it
Re:Thermoacoustic cooling for airconditioning? (Score:2, Interesting)
The issue here is not energy-efficency, it's abandoning ozone-depleateing refrigerants.
Re:Penn Staters (Score:2)
http://conferences.cas.psu.edu/IceCream/icsc.ht
which Ben & Jerry attended.