Process Design for Improved Fouling Behaviour in Dairy Heat Exchangers Using a Hybrid Modelling Approach

The main purpose of this study is the optimization of the heat exchange process in the dairy industry. A tool for simulating heat exchanger performance was fed with technical data of various heat exchanger confi gurations and process variables. Individual plant sections, like the preheater or ultra-high-temperature (UHT) heater, were simulated with modified variables, e.g. water temperatures or heat transfer areas. One modification, developed by simulation, was successfully implemented in a dairy plant. This proved the potential of the simulation software as a tool for design of new plants or the modification of existing plants. Performance rating was done by comparing pressure differences and overall heat transfer coefficients of the original setup and the modification. Improvements of simulated model running times for individual sections of up to 50% were achieved. Advantageous modifications were embedded in a simulation of the complete plant, additionally testing its effects upon milk quality. The main parameters for evaluation of plant performance were the pressure loss over the complete plant as well as the inlet temperature of the UHT heating water while milk quality primarily was rated by inactivation of thermophilic spores and loss of thiamine.