High-pressure homogenization is widely used in continuous processing of emulsions to obtain highly valuable products,such as for foods,pharmaceuticals,fuels,and paintings.In general,the
objective of this energy intensive process is the formation of an emulsion with a specific droplet size distribution in the micron to sub-micron scale. Pressures up to several 1000 bar are used to force the liquid through homogenization units with small cross-section areas,such as valves or orifices.As a result of the contraction the fluid velocity severely increases and induces elongation and shear stresses in laminar and turbulent flow conditions,which may disrupt the dispersed droplets. Additionally,hydrodynamic cavitation can occur in and after the constriction due to the increase in local fluid velocity and there by a decrease of local pressure reaching the vapor pressure of the fluid