Novel Rotor-Stator Assembly Promotes the Emulsification Performance in an Inline High-Shear Mixer

Abstract

For industrial emulsification processes, it remains a challenge to obtain desirable droplet size distribution (DSD) as well as a smaller span via facile and efficient routes. In this work, a novel blind-side rotor is designed to assemble with the stator of a laboratory-scale inline high-shear mixer equipped with an annular cylinder inside the mixing chamber (bRS HSM). The effects of operating parameters, structural parameters on the average droplet size, DSD, and span are experimentally investigated and compared with those of commercially used toothed-type rotor-stator assembly. In addition, computational fluid dynamics calculations are performed to investigate the influences on the flow field of the fluid within the HSM. The results show that the structure of the bRS HSM not only generates an optimal span but also reduces the energy consumption of the mixer, which is more advantageous for production of emulsions with narrower DSD. In the bRS HSM, Sauter mean diameter (d 32) and span decrease with increasing rotor speed but decreasing flow rate of the continuous phase, while span decreases and then increases with increasing volume fraction of the dispersed phase. Meanwhile, the effect of structural parameters on span is nonmonotonic. Furthermore, the artificial neural network (ANN) model is used to perform the correlation of d 32 and span, providing an estimation method to optimize the operating and structural parameters of the inline HSM in the emulsification process.

Modelling W/O/W double emulsions preparation in static mixers: Accounting for the shear-thinning behaviour of the dispersed phase

“…In the double emulsification process, the first step consists of the preparation of a single reverse emulsion using a high-shear device (Ultra-Turrax). Modelling single emulsions is widely addressed in the literature, hence it will not be considered in this study (Gallassi et al, 2019;Li et al, 2022). The modelling task here will focus on the second step dealing with the dispersion of the inner reverse emulsion into the outer aqueous phase within static mixers to form the double emulsion (DE).…”