Hydrodynamics of gas-liquid dispersion in transparent Sulzer static mixers SMXTM

The upward two-phase flow in vertical static mixers is beneficial for dispersion mixing. The bubble size distribution, aspect ratio, and angle distribution of the dispersed phase at various superficial liquid/gas velocities in an industrial Quarto static mixer (QSM) are experimentally studied. The dispersion performance of the QSM is assessed by Sauter mean diameter (d 32), and the empirical correlation of axial d 32 distribution is proposed. The gas–liquid pressure drop in the QSM is measured under U L = 0–0.071 and U G = 0–0.042 m/s, and two new dimensionless empirical correlations are proposed. Based on pressure fluctuation signal time series, the standard deviation, kurtosis, and skewness are analyzed, and the inlet and outlet critical velocities of flow pattern transition from pseudo-homogeneous to heterogeneous in the QSM are identified. Finally, the effect of U G on the dominant frequency and power spectral density function is quantitatively analyzed at the inlet and outlet sections.

Section: Introductionmentioning

confidence: 99%

Bubble Morphology Analysis and Pressure Drop of Gas–Liquid Two-Phase Flow inside a Quarto Static Mixer

Yang

Meng

et al. 2022

“…Researchers conducted extensive studies on the flow characteristics and mixing performance inside the static mixer. − Visualization techniques are typically employed to perform flow field analysis in the mixer. − Jilisen et al conducted a quantitative experimental analysis on the three-dimensional flow field and streamline patterns of Q -type mixers using the three-dimensional particle tracking velocimetry technique. Lobry et al investigated the liquid–liquid dispersion behavior in SMV static mixers experimentally.…”

Section: Introductionmentioning

confidence: 99%

Numerical Study of Flow Field and Mixing Performance of a New Curved-Sheet Blade-Folded Static Mixer

Qiao,

Zheng,

Guo

et al. 2024

Mixing is an important unit of operation in the process industry. A static mixer is a device commonly used for liquid mixing in a pipe or channel. This study proposes a new curved-sheet blade-folded (CBF) static mixer. The CBF mixing element is characterized by folded blades arranged alternatively on both sides of a curved sheet. The features of the flow and mixing of two miscible liquids in the new CBF static mixer, e.g., velocity magnitude distribution, vortices, coefficient of variation, and extensional efficiency, are investigated by using computational fluid dynamics. It has shown that in terms of distributive mixing and dispersive mixing, the CBF performs better than the Kenics, Komax, and LPD static mixers. Compared to the other static mixers, the multicomponent system reaches full homogeneity within a short distance in the CBF static mixer. The radial motion of liquid induced by the vortices is attributed to the intensified mixing performance of the CBF static mixer. Furthermore, this study employs proper orthogonal decomposition to reconstruct the velocity and vorticity fields. It has been shown that the fundamental features of the mixing process can be characterized by the velocity and vorticity fields reconstructed by the first seven modes.

“…The bubble geometric mean diameter decreases from 477.6 to 7.3 μm because of the adequate fluid shear intensified by the helical baffle. Scala et al 25 described in detail the hydrodynamics of gas− liquid flow patterns in a Sulzer static mixer. Compared to the single bubble column, the static mixer has more air hold-up, which can redistribute the bubble size and generate a considerable percentage of the bubble size less than 0.5 mm.…”

Section: Introductionmentioning

confidence: 99%

Microbubble Dispersion Process Intensification Using Novel Internal Baffles

Chen

Song

2022

A bubble generator is a crucial component in the flotation system, and the bubble size is directly related to bubble mineralization. This paper focused on the microbubble size control of a swirl flow microbubble generator. The computational fluid dynamics coupled population balance model (CFD-PBM) was developed to evaluate the flow characteristic and the bubble generation performance of the microbubble generator with five novel internal baffles. The results showed that the baffle could improve the bubble dispersion without extra energy loss, and the single helical baffle could generate tiny bubbles with a Sauter mean diameter of 0.36 mm at a liquid flow rate of 2000 L/h. The baffle could limit the positive axial velocity and hinder the tangential velocity effect in the straight pipe section, weakening the swirl flow effect. Hence, although the baffle slightly reduced the pressure gradient magnitude and the turbulent intensity, it still presented an effective improvement in the bubble dispersion.