In many industries, such as health care, food preparation and electronics manufacturing, cleanliness is of the utmost importance. It's important enough that huge quantities of water are used - and left tainted - in order to remove contaminants. While some groups have concentrated on creating better cleansers, a team of scientists from the University of Southampton have taken a different approach. They've created an ultrasonic tap nozzle, that allows the water itself do a better job at cleaning. The better that a given amount of water is able to clean, the less of it that needs to be used.
Developed by Prof. Tim Leighton and Dr. Peter Birkin, the nozzle generates ultrasound and bubbles, both of which travel down the water stream and onto the surface being cleaned. There, the bubbles enter nooks and crannies in that surface, removing extra material through shear forces. A high power setting can be used on harder surfaces, while a low power setting is better suited to the washing of softer things, like hands or foodstuffs.
When compared to a conventional pressure washer, the nozzle is much more efficient. It uses just 2 liters (half a U.S. gallon) of water per minute, as opposed to the 20 liters (5.28 gallons) used by a pressure washer, and 200 watts of power as opposed to 2 kilowatts. It is also gentler on surfaces, with a stream pressure less than one-one hundredth as strong as that of a pressure washer. Additionally, it generates a lot less airborne water droplets, that can carry contaminants to other surfaces.
Because the nozzle works with cold water, energy that would otherwise go into the heating of water is also saved.
Ultrasound is of course already used to clean items, in the form of ultrasonic water baths that items are immersed in. These baths can only clean objects that are small enough to fit into them, however, and leave those objects surrounded by the contaminants that have just been removed. They also cannot be used on delicate materials.
The Southampton ultrasonic nozzle has already been licensed to partners in a number of industries. A version designed for home use could be on the way.
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