Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Sound waves to chill ice cream in new freezer case concept


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:

More articles from Process Engineering:

nachricht Intelligent wheelchairs, predictive prostheses
20.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

nachricht Jelly with memory – predicting the leveling of com-mercial paints
15.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>