CLEANING OF SOLID BEHENIC ACID RESIDUE FROM STAINLESS-STEEL SURFACES

A rotating disk apparatus was used to study the removal of C-14 labele d docosanoic (behenic) acid from stainless steel. The liquid cleaning behavior was studied as a function of temperature, surface morphology, and fluid flow. A mass-transfer model was proposed to describe the re moval of behenic acid front stainless steel using a rotating disk appa ratus. The cleaning rates computed from the mass-transfer model were c ompared with experimental observations,. it was found that at low temp eratures the removal was a function of rotation speed At higher temper atures, however, the removal rate was independent of the disk rotation speed. In some cases the predicted rate of behenic acid removal diffe red significantly from the observed data. A plausible explanation for these variations is that the residues are removed by the combined effe cts of dissolution and the shearing of large clusters of solid behenic acid crystals. The temperature-dependent behavior of the cleaning dat a was analyzed using an activation-energy-based model.