Drop breakup at reduced energy cost using a turbulent pulse –implications for improving efficiency in emulsification devices

Emulsification devices break drops by rapidly pushing them through a region of intense turbulence–a ‘turbulent pulse’. These devices are widely used in chemical engineering. However, the thermodynamic efficiency is low, and design modifications allowing more breakup at lower energy input is much in need. This study uses a combination of statistical models and direct numerical simulation coupled to high resolution interface tracking to investigate how a turbulent pulse should be designed to reach a desired breakup probability at minimum energy cost. It is concluded that breakup is not determined by the total energy input. Consequently, the energy cost of achieving a given breakup extent could be reduced by carefully tuning pulse amplitude and duration. The optimal pulse is compared to that delivered by homogenizers, revealing that the inability to dissipate turbulent kinetic energy in a sufficiently narrow region is partially responsible for the low efficiency.