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."

noisy

[hugzz]

wouldn't the sound polution kinda reverse the positive environmental effects? and dont tell me to RTFA.. there were too many links, I didn't know where to click :|

I'm amazed B&J's still operates semi-autonomou

[Kuad]

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.

Dangerous

[SlayerofGods]

173 db? That's like liquefy your ear drums loud.... I think most people will stick with frezers that don't kill them.

Reportedly?

[Anonymous Coward]

Buy a thesaurus and learn to write.

Until high volume is reached...

[cnelzie]

...this new refridgeration device will be much more expensive then the 'traditional' designs. Once production ramps up, if ever, the cost of producing this device will equal that of the current cooling technology.

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... After that the goal of energy efficiency can be worked on.

Re:Same Energy as Freon Systems

[kfg]

Nowadays "Green Friendly" means something that you can print on a flyer to drive sales, not something that has anything to do with the enviroment. We've already done away with freon.

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:Peltier cooler?

[Geiger581]

These cool chips still sound a little wishful and/or far off. It's illegal in the US to even use Tritium gas for glow in the dark products, and these things supposedly will require Cesium gas. Will be great if they work and are available for commercial use.

Question

[(ana!)a]

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 !

"quiet operation"?

[roseblood]

"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.

Re:Microwave Fridge

[Detritus]

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.

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:Same Energy as Freon Systems

[WindBourne]

Nah. You just run a gas chromatograph on the atmosphere. It will be expensive, but easy enough to do. It is how we currently obtain a large number of our gases/liquids today.

Re:Question

[Johnny Mnemonic]

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 would break in the summer, and it might be cheaper to cool in the winter using the traditional method than cool in the summer with the inefficiency of the duct;
• it could get too cold--you don't want to keep you milk stored at -20F, you want it at +40F--so you would actually have to heat it up. But why not do this for a freezer?
• The temperature change typical throughout the day might not guarantee that the food stays cold, which could lead to inconsistency and lawsuits over food poisoning.
• Every time you open the door, heat would escape from the room to the outside--and it might be more efficient to keep food cold using the traditional method than to warm up the room again.

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:Ice cream plants are already enviromentally saf

[chrisatslashdot]

...Consider they evacuate large areas when a tanker car of Anhydrous derails it does need to be used with care.

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 you are going to die from the pungent odor long before you suffer any ill health effects. i.e. ammonia causes lawsuits long before it causes any health problems. OSHA's Permissible Exposure Level is 50ppm. That means the average Joe could work 8 hours/day 40 hours/week for a lifetime with no ill health effects at 50ppm. To give you some referece, chopping a strong smelling onion is similar to exposure to about 10-15ppm of ammonia.

With respect to your serin gas analogy, consider water. Water is also fatal in certain quantities [emedicine.com] but I am certain that it is still environmentally safe.

Re:thermal energy back into microwaves in 6 steps

[jgalun]

I know you're making a valid point about the science of this here, but could we lay off the "invading Iraq to steal oil" meme?

1: invade Iraq.
2: Steal the Oil

The US did not invade Iraq to steal oil, for a number of very obvious reasons:

1. Invading Iraq caused oil production from Iraq to dip below pre-war levels, as everyone predicted it would
   
2. Invading Iraq has already cost $200 billion - the equivalent of purchasing 6 billion barrels of oil. Since Iraq produces 2.5 million barrels per day, we'd have to steal about 6 years worth of production to break even. Of course, the US would actually have to steal more than 6 years to break even, because to continue stealing the oil it would have to keep paying to keep its army in Iraq.
   
3. If the US wanted cheaper oil generally and access to Iraqi oil for US companies specifically, the easiest way to do it would have been to drop sanctions in return for Saddam Hussein selling a lot more oil and giving contracts to American companies. Hussein wanted to sell more oil and get rid of sanctions anyway, and would have been happy to throw some contracts to the Americans to get that.
   

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

[MooseByte]

Apologies for the offtopic reply to the offtopic post, folks. ;-)

"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..."

You're looking at it wrong, using hindsight instead of what the Bush administration promised and predicted for how Iraq would "transform". Here's how it was supposed to go, according to the Neocons:

• 0) Invade Iraq and topple Saddam.
• 1) Be greeted by grateful Iraqis, who shower US with flowers and sweets.
• 2) Grab full control of Iraqi oil production and distribution.
• 3) Profit!!!

According to the Neocons, this was going to be a cheap and easy war. According to their plan, the US would have control of Iraqi oil for a pittance.

It's all painfully well documented, even by the Bush adminstration's own quotes and documents (and no-bid contracts). And as many of us knew beforehand, they were painfully, tragically far off the mark.

Re:Question

[CrimsonAvenger]

Nope, spend a lot of time in the kitchen. Anyways, yes, have the oven at head height (chest height, rather). You don't have to have the range on top of the oven - look at a lot of newer kitchens with the oven wall-mounted and the range on an island. Makes much more sense. Then you don't need to have the door to rest things on, just reach in at normal height (or have a slide-out rack).

Have you ever considered a 20 pound (9 kilo for the metric types among us) turkey, plus dressing, within that context? Have you asked your wife about it?

For that matter, have you considered "reaching in" to that nice, hot oven with the turkey inside? It had better be one huge oven, or you're going to have some lovely burns on your arms/hands as you attempt to baste the the thing while inside the oven.

Please note that I do NOT spend a lot of time in the kitchen, but my wife had a few things to say about oven doors swinging up, and ovens at chest height. And while she concedes the latter is done quite a bit these days, she also points out that more often than not, the lady of the house asks her husband to put the turkey in/remove it from such ovens....

Note further that "lady of the house" is my phrasing, not her's. She'd kill me if she knew I used it to describe her.

MY own opinions - a door swinging upward would not prevent heat from escaping the oven, since the entire front of the oven would still be open. Freezer doors that open horizontally (like an ice chest) have been done forever, on large floor deep freezes, such as my mother has in her pantry - works quite well. However, you couldn't practically put a fridge on top of it, or it on top of a fridge, so it would double the floor space required for the combined functionality. At least. Which is not a big deal if you have a big freezer, but for the usual freezer compartment-sized box, it would be impractical.

Large, clear windows in either oven or fridge would tend to be points where heat escapes, either inward or outward. They would reduce the efficiency of the unit somewhat. Whether this would be overcome by the lessened need to open the door is debatable. And besides, how long do you actually spend with the door open when you reach in for a beer/steak/whatever? Would it be appreciably shortened if you could see it in advance? Don't know about the rest of you, but I know where pretty much anything I'll be wanting normally is inside my fridge, and seldom have to actually root around in there looking for things.

And finally, please note that even eskimos use fridges these days - keeps stuff much warmer than outdoors, thus allowing you to thaw things faster. A fridge/freezer is all about controlled temperature, not low temperature per se. Sure, low compared to the inside of the house, but not necessarily low compared to the outdoors.

Re:Refrigeration efficiencies compared - Aerogel

[Anonymous Coward]

There are companies that make aerogel, looks
like you need to be very careful with use and
disposal, since the material is so small..if
inhaled it work better than Abestoes in causing
health problems. So you probably do not want
Aerogels today near customers/consumers.