Bubble Column CFD Model with Effects of Forced Oscillations on Bubble Dynamics

Abstract

Bubble size distribution has a significant effect on gas holdup, residence time distribution, and mass transfer in bubble column reactors (BCRs). The occurrence of small gas bubbles has potential advantages such as a limited residence time distribution and perfect gas‐liquid phase contact. Gas‐liquid mass transfer in bubble columns can be significantly enhanced by subjecting the liquid phase to low‐frequency vibrations. However, the effect of vibration frequency on bubble formation and hydrodynamic characteristics in BCRs is still not well understood. Herein, a 3D numerical model of a BCR was developed to study the effect of vibration frequency on bubble dynamics under different operating conditions. The Sauter mean bubble diameter was found to be approximately inversely proportional to the vibration frequency.

Recent advances in computational fluid dynamics simulation of flotation: a review

“…The predictions of bubble size distribution indicated that the small bubbles concentrated in the impeller stream and lower part of the cell, and a few large bubbles were generated in the upper of the cell due to the bubble coalescence and insufficient impeller agitation. In addition to the mechanically agitated flotation cells, the CFD‐PBM approach has also been applied in the simulation of bubble generation and flow in the flotation column 102,112,113 and dissolved air flotation system 73 . The accurate prediction results would be obtained, and these agreed well with available literature reports and experimental data.…”

Euler–Lagrange Simulations of Microstructured Bubble Columns Using a Novel Cutting Model

“…Several modifications such as sieve trays, structural packing, and vertical packing have been introduced to reduce gas/liquid back-mixing, thus achieving a uniform distribution of relatively small bubble sizes. Without any internal structure changes, it was demonstrated that the use of low-frequency vibrations , and the addition of small particles , can also influence the bubble size distribution and improve the rate of gas–liquid mass transfer. Many studies − were performed on the so-called microstructured bubble column (MSBC), i.e., a bubble column with trays of fibrous catalyst material.…”

Impacts of Particle Properties on Gas Holdup under Four Flow Regimes in Three‐Phase Bubble Columns

“…Much research has been done to better understand the gas holdups in the bubble column. The bubble swarms in the reactor have a highly chaotic nature [23]. The majority focused on the two-phase systems or one flow regime.…”