Ultrasonic spray nozzle and method

TLDR: An ultrasonic spray nozzle includes a piezoelectric transducer which develops mechanical vibrations in response to an applied periodic electrical potential as discussed by the authors, and the vibrations propagate to an atomizing surface over which fluid to be atomized is discharged by an internal fluid passage.

Abstract: An ultrasonic spray nozzle includes a piezoelectric transducer which develops mechanical vibrations in response to an applied periodic electrical potential. The vibrations are mechanically amplified and propagate to an atomizing surface over which fluid to be atomized is discharged by an internal fluid passage. Maximum vibrational amplitude of the atomizing surface is achieved when the frequency of the applied electrical potential equals the natural resonant frequency of the nozzle. A parameter of the applied electrical potential, such as frequency, is periodically varied such that the vibrational amplitude of the atomizing surface is periodically increased and decreased. Fluid atomization is reduced during periods of reduced vibrational amplitude permitting fluid to be distributed with greater uniformity onto the atomizing surface. Such uniform distribution results in a significant improvement in the definition of the spray pattern produced by the nozzle during periods of increased vibrational amplitude. To further enhance uniform fluid distribution, auxiliary fluid passages are provided through the atomizing surface.