Aurizon Ultrasonics is a spin-out from Kimberly-Clark Corporation, where fundamental ultrasonic research had been conducted over a 30 year period. The ultrasonic expertise in Kimberly-Clark was redeployed in Aurizon Ultrasonics in 2009. Aurizon’s core business is designing, manufacturing, and selling high power ultrasonic systems for a variety of Industrial applications. Recently, Aurizon has developed a novel ultrasonic nozzle technology for a broad range of applications where enhancing or enabling the effective atomization of viscous liquids can add value. The prime focus of this development has been incorporating their ultrasonic devices inside of fuel injectors to enhance the atomization and combustion of fuels.
Over $5 million has been invested to develop and protect Aurizon’s unique Ultrasonic Fuel Injector (USFI) technology and applications. Sixty-five (65) US and international patents have been issued, with fifteen (15) more international patents pending. The quick allowance of many key claims speaks to the novelty of the invention.
The basic elements found in ultrasonic devices include a series of waveguides tuned to mechanically resonate at frequencies in the range from twenty thousand to several hundred thousand cycles per second (Hz). The resonant vibration is often created using a piezoelectric transducer that converts an electrical charge into mechanical motion. The working end of these devices is a horn or sonotrode. Aurizon has incorporated these design elements into a patented system where an ultrasonic device fits inside a custom-engineered pressure chamber (e.g. injector body) in a way that enables virtually all the ultrasonic energy to be delivered to the liquid being atomized. The USFI device applies intense ultrasonic energy to a pressurized liquid immediately before it exits the orifice.
This technology has been proven to change several conditions that enhance the spray process and therefore the atomization characteristics including:
- The extensional mode of vibration in the USFI device causes a rapidly alternating change in velocity of flow of the liquid at ultrasonic frequencies – typically 20 to 50 kHz – resulting in significant collision of droplets after they exit the orifice.
- The high velocity liquid collides with the lower velocity liquid ahead of it and causes enhanced jet break-up, higher-velocity plumes for improved penetration, and increased lateral expansion (as seen in Photo #2 of the high speed photographs below) which improves air entrainment and plume volume.
- The high frequency oscillation of the ultrasonic horn induces a tremendous shearing effect on the liquid which is very effective in creating atomization of high viscosity fuels.
- The intense “pumping” action of the ultrasonic horn face has been shown to reduce nozzle plugging as well as to clear nozzles that are already plugged.
Pilot scale testing of USFI technology has successfully demonstrated the ability to:
- Improve atomization of a broad range of liquids without changing system conditions (e.g. pressure,
- Enable the effective atomization of very viscousliquids (>20,000 centiPoise) that are otherwise difficult to atomize
- Handle a broad range of flow rate possibilities, from several g/min up to >15 kg/min.
- Work with with intermittent flow applications where the activation of atomization requires precise control (e.g. instantaneous atomization of pulsed liquids)
- Provide instantaneous heating of liquids being atomized with ultrasonic energy
- Provide particle size “tune-ability’’ by varying ultrasonic amplitude to change the mean particle size of the atomized droplets