Using precoated whey protein concentrate gel films as a model milk protein fouling material, the removal kinetics from the inner surface of a stainless steel tube were determined continuously and noninvasively by a rapid UV spectrophotometric method. The influences of temperature, flow velocity, and the amount of fouling on the cleaning behavior were evaluated. For the first time, a cleaning model combining polymer dissolution and boundary layer mass transfer has been used to describe the cleaning process. It is suggested that the disengagement of protein molecules from the swollen gel-solution interface and the transfer of these disengaged protein molecules into the bulk cleaning solution are the rate-limiting steps in the range of conditions examined. The experimental results agree with the predictions of the cleaning model. The application of the current cleaning model to milk protein and whey protein fouling systems reported by various researchers is also discussed. (C) 2004 American Institute of Chemical Engineers.