A more efficient and eco-friendly dishwasher is being developed

By Gwyn Wright and Lilli Humphrey via SWNS

A prototype model of a more efficient and eco-friendly dishwasher has been created by scientists in Germany.

Researchers say superheated steam dishwashers will prove more effective than existing ones which use huge amounts of water and do not kill all the harmful bacteria on plates, bowls and silverware.

The new gadgets clean 99 percent of bacteria on a plate in just 25 seconds, according to the team behind the device.

While the appliances are more expensive to buy, they would save people money on water, electricity and detergent in the long run because they are more efficient.

They would be ideal for use in restaurants, hotels and hospitals, the researchers claim.

A team from the Technical University of Dortmund created a simulated model of an ideal dishwasher which looks like a box with solid side walls, a top opening, and a nozzle at the bottom.

A plate covered with a heat-resistant strain of bacteria sits directly above the nozzle.

Once the plate reaches a certain temperature in the simulation, the bacteria are deemed dead.

Steam comes out of a nozzle very quickly.

The model also shows heat transfer- how the heat changes in the simulation box and condensation on solid surfaces.

Shock waves, created by the high speed of the steam, are reflected onto surfaces in the dishwasher.

While the simulations only use one plate, the researchers say bacteria will still be killed much more quickly and efficiently in a real version than in existing technology.

Study author Dr. Natalie Germann, of the Technical University of Dortmund, said: "We confirmed that the dishwasher application using superheated steam is promising.

"This is the first work combining fluid dynamics and heat transfer with phase change and bacterial inactivation.

“It lays the foundation for future computational research and further technical work."

The findings were published in the journal Physics of Fluids.