Relevance of Particle Transport in Surface Deposition and Cleaning

Multiple mechanisms are involved in the deposition of particles on various surfaces encountered in industrial processes. In this chapter, the most common and influencing mechanisms of particle deposition are described. The physical aspects of the effect due to dry deposition, thermophoresis, electrostatic force, and dielectrophoresis on particle deposition on surfaces are delineated and emphasized to strengthen their relevance in contaminant removal and surface cleaning. The applicable range of a specific theory and related caveats when applied to an industrial setting are also provided throughout the discussion. Surface cleaning by mechanical means can be achieved by abrasive erosion from impingement of fine and hard particles on the surface to be cleaned. The effectiveness of abrasive erosion depends on impact velocity, impact angle, and materials involved. The available empirical correlations are typically application oriented, they are valid for specific applications and within a narrow range of parametric conditions. One particular difficulty in model generalization of abrasive erosion for practical applications is the low predictability of particle behaviors in turbulent jets and boundary layer flows over rugged (eroded) surfaces. Theories with a much-wider applicability and a deeper scientific basis are yet to be developed.