Fouling reduction during milk processing using equipment surface modification

Fouling of equipment surfaces during milk processing is a phenomenon that needs to be immediately addressed due to the increased energy utilization and production costs encountered. Modifying the equipment surface is one method of reducing the incidence of fouling. Research was carried out at the Pennsylvania State University using different food-grade surface coatings to modify plate heat exchanger surface, and was tested for their ability to reduce fouling during skim milk pasteurization. The results were compared with traditional stainless steel 316 plate heat exchanger (PHE) surfaces typically used in the food industry. Results after 6 h continuous testing using a pilot scale PHE unit indicate that there was greater than 85% reduction in fouling when the three coated surfaces (AMC 148-18, Ni-P-PTFE and Lectrofluor™-641) were used. Chemical analyses of the foulants indicate that the coating integrity did not appear to be compromised for the Lectrofluor™-641 coatings. However, there were trace amounts of fluorine present in the foulants adhering to the other two coating types (AMC148-18 and Ni-P-PTFE). A preliminary cost estimate on the thermal energy savings when using the coated surfaces indicate that there is substantial savings in energy, further justifying the use of these coated surfaces, and making them more attractive for possible implementation in the food industry.