Method for Producing Fine Liquid-Drop Systems in Ultrasound Fields

Abstract

This study is devoted to theoretical research on two-stage fine spraying of liquids that consists of the primary formation of large drops under the effect of ultrasound on a thin liquid film and the secondary breakup of generated drops under the influence of a high-frequency acoustic field in an air-drop medium. A physical mechanism is revealed and a physicomathematical model is proposed for the breakup of drops, which makes it possible to determine the threshold levels of acoustic pressure for various drop sizes, properties of a sprayed liquid, and types of action. It is found that the most effective method of acoustic action is the sequence of different-frequency pulses at a high aerosol concentration (greater than 10 vol %), which creates conditions for intermode dispersion. It is shown that, under the effect of continuous single-frequency vibrations, the radiator power necessary for drop disintegration can exceed 550 kW. Under pulsed action, the required power decreases to 2 kW at a radiating surface area of 800 cm².