Fouling reduction during milk processing using equipment surface modification

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