Process Technology of hot gas atomization process for rheological complex liquid feed for production of powders with given properties

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The object of this reasearch project is the design of spray processes for the production of powder material from feed materials with complex rheology using hot gas as assisting fluid. The process design includes the experimental analysis of the breakup of complex viscous media, the multiscale process simulation and the powder production with the hot-gas atomization process at pilot-scale. The atomization of complex-viscous feed materials (e.g. with viscoelastic behaviour) is of great importance in industrial applications. Under conventional atomization process conditions the breakup of liquids with complex rheology may not be complete. This results in a high fiber fraction within the product. The aim of the project is to enhance the atomization effectivity with the use of hot gas in an external mixing twin-fluid atomizer. The hot air is also used to directly dry the spray droplets. The resulting drying kinetics are predicted applying multiscale simulations. Thus the influence of integral as well as local flow phenomena on the heat and mass transfer in the spray can be analysed. For instance the local clustering of droplets has a huge impact on the drying behaviour of individiual droplets. The main objective of the project is the deterministic prediction of a process frame, wherein the desired product properties (powder properties) within the hot gas atomization process can be produced taking into account the safety and stability of the process.