Pinoy students develop ultrasonic washing machine

For centuries, washing laundry has always required a "particular" cleaning agent —from ashes and silicates of the Egyptians to your mom’s choice of detergent— to go with water.

 

But a group of young Filipino engineering students thought otherwise. Their solution: ultrasonic cleaning method.

 

Keith Michael Basa, Kristina Paula Gomez, Alvin Quinio and Ferdinand Navarro-Tantoco, graduating electronics and communication engineering students of De La Salle University (DLSU) Manila created a prototype that could be used to ease home laundry duties without harmful effects to the environment. 

 

In their study, “Prototyping of an ultrasonic test machine for washing fabrics”, they designed a prototype of an ultrasonic washing machine and tried to clean several types of fabric with different kinds of stains from animal blood, to coffee and ketchup.

 

And they succeeded.

 

Ultrasound in cleaning

 

An ultrasonic cleaner uses ultrasound (sound with frequency usually from 20–500 kHz) together with a solvent such as water to clean various items.

 

The high-frequency sound waves agitate the contaminants such as soil, grease, lime scale, dust, dirt, pigments, rust, bacteria submerged in a liquid in a process called "cavitation."

 

During cavitation, the fluctuations of the sound waves create very small bubbles which then pop, creating millions of micro-jet streams of liquid. This process helps dissolve the contaminants and removes them from the object being cleaned.

 

Ultrasound technology has long been used in cleaning jewelries, lenses and other optical parts, dental and surgical instruments and implements, coins, fountain pens, watches, windows, firearms, and industrial and electronic equipment.

 

Prototype washing machine for fabrics

 

However, ultrasonic cleaning technology has not been really utilized for fabrics, especially in the Philippines.

 

With nine months of tedious research, trial and error experimentation, the La Salle students were able to come up with a prototype washing machine, mainly composed of three sections: the signal generator, transducer, and the tank.

 

“We are proud to say that we did the design for the ultrasonic driver by ourselves,” said Navarro-Tantoco, one of the students who did the project.

 

Basically, their prototype works this way: when the ultrasonic driver is switched on, electricity powers the transducer (a type of energy converter) which produces vibrations applied to the water inside the tank. The stain on the fabric submerged in water slowly dissolves as ultrasonic waves act on it. After a few minutes, the fabric is free of stains and machine can be turned off.

 

Greener solution

 

One of the main goals of this project is to find a way to reduce electric consumption and negative environmental impact of other types of cleaning technology.

 

The prototype uses 50 watts (it could go up to 250 watts, depending on the number of transducers used) while a typical washing machine uses an average of 500 watts. 

Of course, ultrasonic cleaning also minimizes the consumption of laundry detergent and the pollution that results therefrom.

 

Potential for further studies

 

“The students did a great job. I am proud and admire them. It was a hard and challenging learning process,” said Dr. Celso Co in an email, one of the advisers of the students, together with Engr. Gerald Arada of DLSU.

 

Not only was the group able to come up with a prototype, they were also able to come up with preliminary standards for ultrasonic cleaning in fabrics. The standard includes information about the type of fabric, temperature, cleaning medium used and the frequency during operation.

 

All of this information, together with the prototype machine, serve as a good starting point in another technological innovation that could probably be available commercially in the future.

 

In May, the group will present their study at the Institute of Electrical and Electronics Engineers-Philippines (IEEE Philippines) in a conference to be held in Cebu City. — TJD, GMA News