Improving the separation efficient of particles smaller than 2.5 micrometer by combining ultrasonic agglomeration and swirling flow techniques

The method for increasing the separation efficiency of particles smaller than 2.5 micrometers by combined ultrasonic agglomeration and swirling flow technique is proposed in the article. The swirling flow creates areas with an increased concentration of particles on the outer radius of the vortex. The ultrasonic exposure on these areas leads to more efficient agglomeration and the formation of agglomerates of many times larger than the original particles. The resulting agglomerates are easily separated from the gas flow. The design of the agglomerator was developed. The vortex velocity is determined, at which ultrasonic exposure on the swirling flow increases the average particle size d(32) = 2.5 micrometer to 4.5 times. The ultrasonic exposure on a rectilinear flow can increase the particle size no more than 1.6 times for comparison. The proposed method is compared with inertial gas clearing in a cyclone. It was found that the proposed combined method allows increasing the cleaning efficiency from 46% to 85% at ultrasonic exposure on the swirling flow in the agglomerator and cyclone.