Influence of Flow Conditions in High-Pressure Orifices on Droplet Disruption of Oil-in-Water Emulsions

Flow conditions in and behind high‐pressure orifices are described by a characteristic correlation between discharge coefficient and Reynolds number. The use of a pressure vessel and variations in viscosity allowed for non‐pulsating flow conditions from laminar to turbulent flow. Emulsions were homogenized under each condition. A considerable difference was observed in the final droplet size distribution depending on laminar, transitional, and turbulent flow. When the flow was pulsating as found when applying a plungers pump, transition of the flow from laminar to turbulence was more difficult to detect. Emulsions homogenized under these conditions indicated broader droplet size distributions. The Sauter mean diameter, however, was not affected by the pulsating flow. Adjusting the droplet size of emulsions is crucial since it determines main product properties. In high‐pressure homogenization the droplet disruption is strongly influenced by the local flow conditions. A method is proposed to give an estimate on the flow conditions in high‐pressure disruption units. Resulting droplet size distributions are related to the existing flow conditions.