Investigation on drawdown dispersion process of light floating particles in a pilot scale jet flow high shear mixer

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2025-01, Vol.504, p.158591, Article 158591
• Main Authors: Liu, Yudong, Dang, Xiuhu, Liu, Xiaobang, Zi, Can, Liu, Huajie, Li, Jianchang, Li, Wei, Zhang, Jinli
• Format: Article
• Language: English
• Subjects: Drawdown dispersion; Jet-flow high shear mixer; Light floating particles; Solid-liquid two-phase flow
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.158591

•A pilot scale jet-flow HSM was applied to accelerate drawdown dispersion process.•It can easily complete drawdown dispersion in high solid content up to 40 %.•The mechanism of drawdown dispersion of light floating particles was revealed.•Mathematical models for estimation of the Njd and Pjd were established. The jet-flow high shear mixer (HSM) was applied to accelerate the drawdown dispersion process of light floating particles. It can easily complete drawdown dispersion operations in high solid content up to 40%. The process analysis on drawdown dispersion was performed by high-speed camera and CFD simulation. The critical speed Njd, critical power consumption Pjd, and particle dispersion uniformity σ2 were experimentally measured. The central vortex, turbulent fluctuation and drag force are main driving force in the first stage, while the forced suction and spraying of rotor–stator shear head are main driving force in the second stage. Increasing rotor speed can enhance the mixing efficiency. Within the range of 40 %, the higher the solid content, the more energy-efficient the jet-flow high shear mixer. The Njd and Pjd were significantly reduced when using downforce rotor, and stator with a fully open bottom, while the dispersion uniformity was increased. Adopting an eccentric arrangement can reduce the Njd and Pjd, but it is not recommended as it can lead to uneven particle distribution. Dimensionless correlations were established to estimate the Njd and Pjd of jet-flow high shear mixer, which can provide effective guidance for its practical application.