Fluidized bed degreasing (fbd) of metal components

Degreasing is one of most important stages of modern transformation processes in industries fabricating or assembling metal parts, such as in manufacturing of aircraft, appliance, automobiles, electronics, and railroad equipment. Chemical degreasing processes mostly employ chlorinated solvents in a liquid or vapour state in order to remove oils and oil-borne soils from previously processed parts, such as chips, metal fines and fluxes. Nevertheless, increased sensitivity to the environmental impact of cleaning agents is pushing scientists and technicians towards the development of alternative solutions. In this study, a relatively novel eco-efficient degreasing technique, namely Fluidized Bed Degreasing (FBD) based upon a fluidized bed of hard particles has been proposed. In this system, a bed of spherical shaped glass particles was taken in a fluidlike state in a confined fluidization chamber by using a low pressure air flux. The resulting impacts of the fluidized particles on the surface of targets to be degreased caused the removal of surface contaminants and the concurrent accurate cleaning of the exposed surfaces. In this context, a detailed experimental campaign was aimed at investigating the interrelationship among FBD operational parameters and degreasing effectiveness, with particular interest towards the analysis of target geometry and location inside the fluidized bed. Consistent trends of residual oil according to FBD process parameters were plotted and the influence of each individual operational variable understood. A related analytical model, basis for the development of more sophisticated control modulus, was developed and verified by the experimental findings. Finally, the reliability of FBD process even on complex shaped surface like pipes and blind holes was assessed.