Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sound waves to chill ice cream in new freezer case concept

04.12.2002


Penn State acousticians have achieved proof of concept for a compact ice cream freezer case based on "green" technology that substitutes sound waves for environment-damaging chemical refrigerants.



Dr. Steven Garrett, the United Technologies Corporation professor of acoustics at Penn State, leads the research team conducting the project with financial support from Ben & Jerry’s and its parent company, Unilever.

"In our proof-of-concept test system, there is no ’test freezer,’ we simply cool an electrically-heated piece of window screen. The coldest temperature we have achieved with this test rig is eight degrees below zero – well below the freezing point of water," Garrett says.


However, although the test rig doesn’t look anything like the freezer display case where you usually pick up your pint of Cherry Garcia, Garrett says it is a big step in the "green" ice cream sales cabinet direction.

"We have achieved proof-of-concept for making a compact chiller that has a volume which is substantially smaller than earlier thermoacoustic chillers," he explains. "And we did it with a system that was carefully and redundantly instrumented for both accurate performance measurement and performance diagnostics."

The team’s progress will be detailed in a paper, "Performance of a Small Low-Lift Regenerator-based Thermoacoustic Refrigerator," Wednesday, Dec. 4 , 2002 at the First Pan-American/Iberian Acoustics Meeting in Cancun, Mexico. Matthew Poese, doctoral candidate in acoustics, is first author of the paper. The work is part of his doctoral thesis.

Garrett explains that his group’s thermoacoustic chiller uses a souped-up loudspeaker to generate high amplitude sound energy in an environmentally safe gas – currently the air we breathe – that is converted directly into useful cooling. The high amplitude sound levels are hundreds of thousands of times beyond even rock concert levels.

The loudspeakers used in thermoacoustics do not need to produce a range of frequencies or tones like a radio. So, Garrett’s group improves their efficiency by operating them at resonance or at the tones they produce by the natural free oscillation of the system. The Penn State group has developed loudspeakers that not only operate near their natural resonance frequencies but also use metal bellows that replace loudspeaker cones to compress the environmentally safe gas -- air in the test case -- used for chilling.

"We have been operating loudspeakers at resonance and using bellows in thermoacoustic devices for 20 years," Garrett adds. "Now, by putting the entire refrigeration core inside the bellows, we’ve substantially reduced the size."

Robert Smith, the third member of the Penn State Applied Research Laboratory team working on the Ben & Jerry’s project, made important contributions to the loudspeaker in his master’s thesis.

Garrett notes, "What began as basic research on the fundamental connections between sound waves and heat transport, funded by the Office of Naval Research, is getting closer to providing an environmentally benign substitute for traditional engine and refrigeration technology."

Gary Epright, Ben & Jerry’s lead process engineer, said "I am proud that Ben & Jerry’s has taken the initiative to explore this beneficial technology with Steve Garrett’s team at Penn State. It is a tremendous opportunity to participate in an innovative technology that could revolutionize the way we understand and use refrigeration. With refrigeration based on sound, using environmentally safe gases, we could go a long way toward restoring atmospheric balances."

Barbara Hale | EurekAlert!
Further information:
http://www.psu.edu/

More articles from Process Engineering:

nachricht Harder 3D-printed tools – Researchers from Dresden introduce new process for hardmetal industry
11.10.2018 | Fraunhofer-Institut für Keramische Technologien und Systeme IKTS

nachricht Flying High with VCSEL Heating
04.10.2018 | Fraunhofer-Institut für Lasertechnik ILT

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Purdue cancer identity technology makes it easier to find a tumor's 'address'

16.11.2018 | Health and Medicine

Good preparation is half the digestion

16.11.2018 | Life Sciences

Microscope measures muscle weakness

16.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>