THE DISRUPTORS

A refrigerator that uses sound to keep your prodcue cool. It’s not science ence fiction.

THERE HAVE BEEN changes and improvements in terms of design, as well as modernisations which now see refrigerators becoming IOT connected devices, but the mechanics that allow your fridge to operate have remained largely the same.

Adam Alcock, an Mtech student at the University of Johannesburg,- has showcased a prototype of a new type of fridge which uses thermoacoustics instead of traditional coolant or refrigerant to keep your produce cold.

Thermoacoustics is the interaction between temperature, density and pressure variations of acoustic waves.

Alcock’s prototype utilises this technology to create a refrigeration system that has no moving parts and is far safer and less harmful to the environment than a standard home fridge.

The prototype – known as Tadtar – is essentially a long pipe which uses a catalytic converter and nichrome coil (the same as one you’ll find in your toaster) on one side, with a second catalytic converter on the other side.

Heat is applied to the coil which is on the face of the catalytic converter. This, in turn, agitates the gas. The gas then compresses and expands – thanks to the heat source – through the catalytic converter and a soundwave is produced.

The sound travels down the pipe and reaches a second catalytic converter, which converts this agitated gas and energy. The result is that one side of the catalytic converter is hot while the other side is cold.

Alcock admits that the prototype is not perfect and that performance is not at the same level of a traditional home refrigerator.

The aim of his dissertation was to find out how thermoacoustics works and how adjusting the length of the prototype could affect the sound frequency and, ultimately, performance.

This is not the first thermoacoustic refrigeration system, there are examples of this type of technology being used internationally, but there are currently no commercial applications.

The greatest benefit of Tadtar is that it can be powered using solar energy, which ultimately makes this a great alternative to people living in rural areas who do not have access to electricity.

PAIN POINTS

Correct materials need to be used. Power output isn’t high, far less than traditional fridges. Efficiency. Working with sound is temperamental and difficult to control.

ABOVE: Adam Alcock, Mtech student at the University of Johannesburg