Improving Agglomeration Efficiency of Aerosols with Sizes Less than 2.5 Μm by Generation of Vortex Streams in Inhomogeneous Ultrasonic Field

In this paper, a new approach to increasing the efficiency of agglomeration of finely dispersed aerosols by generation of toroidal vortex streams in inhomogeneous ultrasonic field is proposed and studied. It could be established form the obtained experimental results (for two types of emitters) that the toroidal vortex streams generated in a non-uniform ultrasonic field ensure an increase in agglomeration efficiency when exposed to gas-dispersed flow injected into the agglomeration chamber at a speed of up to 0.2 m/s. Further increase in the injected flow speed results in disruption in the structure of generated vortex streams, and agglomeration efficiency decreases.It was established in the course of analysis that efficiency of agglomeration due to toroidal vortex streams increases in direct proportion with increase in sound pressure level up to 165 dB. After that, no further increase in agglomeration efficiency is observed.It was possible to verify by virtue of analysis of the fractional efficiency of the proposed approach that the efficiency of agglomeration in comparison with agglomeration in a homogeneous ultrasonic field for droplets with a size of 0.2 ... 0.6 μm increases by 25%; for droplets with a size of 1.8 μm by 20%; and for droplets larger than 2.5 μm, the increase in efficiency is no more than 17%.