A Laboratory Investigation of Milk Fouling Under the Influence of Ultrasound

In this study, a lab scale device was constructed to conduct an initial investigation of milk fouling under the influence of ultrasound. Milk fouling was prevented in some circumstances over 2 h of heating. For similar heating conditions and in the absence of ultrasound in heat transfer, serious fouling was developed within only 1 h. The enhancement caused by the ultrasound (up to 62%) reduced the solid–liquid interface temperature for the same heating duty, leading to considerable reduction in fouling. The ultrasonically induced movement of the depositing species in the near wall region is also thought to be responsible for fouling reduction as it does not allow the molecules to stay at the wall longer than the time needed for them to form a firm deposit. The observations reported in this study form a good basis for a more detailed and systematic investigation in the near future.