Ultrasound-modulated two-fluid atomization

Abstract

The present invention is a dramatic enhancement of the two-fluid atomization art through the discovery of a method of causing resonance between capillary waves in the ultrasound range in a flowing liquid stream and the waves created at the surface of that stream of liquid by an impinging gas stream. In the present invention, the surface of a stream of liquid issuing from the outlet or nozzle of an ultrasonic atomizer is impinged upon by a stream of gas. That impinging stream of gas then develops, at the surface of the liquid stream already sustaining its own wave motion, a flow of gas substantially parallel to the flow of the liquid stream that moves faster than that surface of the liquid stream. The flow of the gas at the surface of the liquid stream moves sufficiently faster than the surface of the liquid stream to generate waves at the surface of the liquid stream. The wavelength of the waves generated by the impinging gas on the surface of the liquid stream are modulated by velocity control of the impinging gas stream and resonate with the liquid stream waves. The resonance results in an atomization wherein the droplets are smaller and the droplet size distribution is reduced over prior art ultrasonic atomizers.