Ultrasonic agglomeration and preconditioning of aerosol particles for environmental and other applications

This chapter reviews the state of the art sonic agglomeration process of aerosols, including basic mechanisms and practical applications. This process, studied since the first half of the twentieth century, is currently of renewed interest in connection with the increasing social sensitivity to environmental and energy problems. In fact, sonic agglomeration can be used as a form of fine particle filtration by increasing the particle micron and/or submicron sizes to a size where they can be readily collected. The main effects induced by the application of high-intensity sonic and/or ultrasonic waves to an aerosol together with the motion and interaction of aerosol particles are presented through different theoretical treatments and numerical models. Finally, the most relevant experimental results at laboratory and semi-industrial scales are summarized and discussed.