Integration of a fully 3D CFD model in a lump parameter system simulation

Carlo Torelli (Tetra Pak)

A controlled environment is maintained in the aseptic chamber of a filling machine by sterilizing the gas phase in a complex sterile system composed by heat exchangers, a blower, valves and de–humidificators. The filling machine accomplish different steps in order to prepare itself to the real production and the sterile system provides different flow conditions in relation to specific phases like pre-heating, sterilization and drying of the aseptic chamber.











Challenge - A new proportional change over valve has been studied by Tetra Pak in order to increase the flexibility of the filling machine and to optimize the air temperature in the aseptic chamber.

Solution - The construction of a lumped parameters model (1D) is the best strategy to simulate the system in particular to cover transient flow condition though each component. The topic of the presentation covers the methodology applied to resolve the flow inside a sterile valve using 3D CFD simulation and a DOE sequence on shutters rotation angles. Afterward the different flow splits calculated are post processed building a response surface that is used in the lumped parameter model to characterize the valve element.

Results - New proportional changes have been introduced over the valves of the sterilization system helping engineers to increase the flexibility of the sterile system, optimize the temperature of the aseptic chamber and optimize the control system of the hot air flow to the aseptic chamber.