Novel techniques for cleaning surfaces contaminated with solid particles

Aerosol particles readily deposit on and adhere to solid surfaces, which often represents significant environmental hazard. An efficient removal of these particles from contaminated surfaces is a challenge recognized in many industries, particularly in the nuclear fusion facilities, where beryllium particles and other radionuclides are aerosolized due to interaction with plasma flow and deposit on various surfaces. The conventional particle removal methods have limitations, for instance, some lead to the secondary environmental contamination while other offer low particle removal efficiency. In this effort, we introduced a novel technique that features the air jet surface treatment with vacuuming. Based on an extensive testing conducted using the gravimetric method with polydisperse aluminum surrogate particles on six different surfaces, the novel technique demonstrated a very high particle removal efficiency, ranging approximately from 95.4 +/- 3.5% to 99.3 +/- 0.2%. These are significantly higher than the efficiency, which we obtained using the high-speed rotating brush - a reference device developed and used in this study as a control. The findings were confirmed by experiments conducted with monodisperse fluorescent polystyrene latex (PSL) particles of three sizes. Adding ultrasonication significantly improved the performance achieved by the air-jet technique. The advanced prototype, which deployed the air jets with vacuuming, enhanced by ultrasonication demonstrated a particle removal efficiency ranging approximately from 99.3 +/- 0.3% to 99.6 +/- 0.2% for rough plastic surfaces to 99.8 +/- 0.2% to 99.9 +/- 0.1% for smooth surfaces of glass, stainless steel, and plastic. The new particle removal technique has shown its great potential for the application in fusion reactor facilities and other industrial installations. Copyright (c) 2022 American Association for Aerosol Research