Effect of Particle Impact on Surface Cleaning Using Dry Ice Jet

The removal of particulate contaminants adhering to a surface has been investigated using a dry ice blasting system. Monosized spherical latex particles of micron and submicron sizes were used as particulate contaminants, while the dry ice jet was produced by the thermal expansion of liquid carbon dioxide (CO2). Removal of the contaminants was observed in situ using a high-speed microscope camera and quantified through digital image analysis. The experimental results showed that dry ice blasting performs well for surface cleaning, which is attributed to the collision of the dry ice particles with the contaminants. For submicron-sized contaminants, a lower temperature jet was required in order to produce a larger number of dry ice particles to enhance the removal efficiency. The removal efficiency increased with an increase of the jet pressure on the surface. In addition, a theoretical analysis of the moments of forces caused by particle impact and aerodynamic drag showed that particle impact is primarily responsible for removal. Furthermore, the effect of the dry ice cleaning was visually observed by applying it to the removal of a film resin covering a surface.