Abstract
We studied the adhesion of spherical glass particles and fly ash to glass and metal substrates using an ultracentrifuge or air at high velocity to achieve particle removal. Adhesion forces increased with increased particle size and ambient air relative humidity, but decreased with increased surface roughness. By properly charging the surface, adhesion could be increased or decreased. Boundary layer theory was used to calculate air drag acting on adhering particles subjected to a high-velocity air stream. Increased time of exposure did not increase particle removal in a centrifugal force field, but it did have this effect with high-velocity air. This result was interpreted on the basis of turbulent eddies penetrating the laminar sublayer to reach adhering particles. Alternately, adhering particles could create turbulance in their immediate vicinity.