Effect of calcium content and flow regime on whey protein fouling and cleaning in a plate heat exchanger

Fouling and cleaning with a whey protein concentrate solution in a plate heat exchanger were investigated with a varying calcium concentration (from 70 to 87.5 mg L-1) and under a wide range of hydrodynamic conditions for a bulk fouling fluid temperature, ranging from 60 and 96 degrees C. This work demonstrates that increasing the calcium concentration in whey protein concentrate contributes to the amount of fouling and affects the thermal conductivity of the deposit. It was also observed that the fluid flow regime during fouling, impacts the deposit growth, modifies the structure of fouled layers and has a significant consequence on cleaning behaviour. Finally, a dimensional analysis together with experimental measurements, allowed a relationship to be established enabling prediction of the amount of dry mass deposited locally as a function of the known calcium content, Reynolds number and bulk fluid temperature. (C) 2014 Elsevier Ltd. All rights reserved.