Design and development of high shear mixers: Fundamentals, applications and recent progress

Abstract

Dispersion of liquids/particles is a key important requirement in a variety of applications including coatings and paints, cosmetics, healthcare, food, and pharmaceutical processes. In all these industrial processes high intensity of energy is required to overcome the adhesion forces or increasing interfacial surface area per unit volume, which is achieved by high-pressure homogenizers, ultrasonic-assisted devices, and high shear mixers (HSMs). In this paper, HSMs are critically reviewed based on their design and development, and applications (such as dispersion of nanoparticles, emulsification, and mixing) in recent years. HSMs are comprised of rotational (rotor) and stationary (stator) parts with a small gap in between. It is found that there is a significant influence of stator geometry on the uniform size distribution as well as energy dissipation. Though there is extensive work on hydrodynamics and mixing in HSMs are available however, still there is no specific scale-up/down criterion is available for HSMs.