FEM-based time-reversal enhanced ultrasonic cleaning

Joonas Mustonen; Oskari Tommiska; Axi Holmström; Timo Rauhala; Petro Moilanen; Maria Gritsevich; Ari Salmi; Edward Hæggström

doi:10.1016/j.ultsonch.2021.105798

FEM-based time-reversal enhanced ultrasonic cleaning

Ultrason Sonochem. 2021 Nov:79:105798. doi: 10.1016/j.ultsonch.2021.105798. Epub 2021 Oct 15.

Authors

Joonas Mustonen¹, Oskari Tommiska², Axi Holmström², Timo Rauhala³, Petro Moilanen⁴, Maria Gritsevich⁵, Ari Salmi², Edward Hæggström²

Affiliations

¹ Electronics Research Laboratory, Department of Physics, University of Helsinki, P. O. Box 64, 00014 Helsinki, Finland. Electronic address: joonas.mustonen@helsinki.fi.
² Electronics Research Laboratory, Department of Physics, University of Helsinki, P. O. Box 64, 00014 Helsinki, Finland.
³ Altum Technologies, Finland.
⁴ Electronics Research Laboratory, Department of Physics, University of Helsinki, P. O. Box 64, 00014 Helsinki, Finland; Altum Technologies, Finland.
⁵ Electronics Research Laboratory, Department of Physics, University of Helsinki, P. O. Box 64, 00014 Helsinki, Finland; Finnish Geospatial Research Institute (FGI), Geodeetintie 2, 02430 Masala, Finland; Institute of Physics and Technology, Ural Federal University, 620002 Ekaterinburg, Russia.

Abstract

Pipe fouling is a challenging problem in many industrial applications. Current cleaning techniques require halting the production during the cleaning phase and the existing methods are unable to do targeted cleaning, even though fouling is often localized to certain areas inside the pipeline. To address this issue, we use FEM-simulated, time-reversed signals to focus ultrasound power onto a pre-determined location: a fouled pipe residing inside a Plexiglas container. Ultrasound cleaning with similar acoustic power was compared to the time-reversal enhanced method in terms of cleaning efficiency. The cleaning efficiency was determined by measuring how much fouling, by mass, both protocols removed from the surface of a Plexiglas pipe, using similar input electric power and equal cleaning time. Our results indicate that the proposed time-reversal-based technique removes three times more fouling than the standard ultrasound cleaning without focusing. The study extends our previous paper on FEM-based time-reversal focusing [1].