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

Abstract

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.

Improvements in emulsion stability of dairy beverages treated by high pressure homogenization: A pilot-scale feasibility study

“…It is well known that the droplet size is strongly influenced by the flow conditions, namely laminar, transitional and turbulent regime (Finke et al, 2014;Kelemen et al, 2014;Schlender et al, 2015). In this study, the calculated Reynolds number at the homogenization gap reveals a turbulent regime within the experimental conditions (2000≤Re≤5000).…”

Influence of Cavitation and Mixing Conditions on Oil Droplet Size in Simultaneous Homogenization and Mixing (SHM)

“…It is generally accepted that in HPH processes a superposition of these mechanisms takes place. In several studies, it was observed that droplets are elongated at the entrance of the orifice [25,26]. However, this elongation was not sufficient for the break-up of droplets, which was located downstream the orifice due to turbulence.…”

Extending Applications of High-Pressure Homogenization by Using Simultaneous Emulsification and Mixing (SEM)—An Overview

“…In orifices, for example, the droplets are first elongated in the inlet area [10] and then disrupted in the turbulent and cavitating flow in the discharge area [26,27]. On top of that, the components of the emulsions influence the flow regimes and thus the mechanisms predominantly responsible for droplet breakup [28][29][30][31]. Further information on droplet breakup can be found in our second paper in this journal.…”