Abstract:
Gas-liquid interaction is very crucial in many process industries like pharmaceutical, biochemical, and petrochemical. For Gas-Liquid interactions, bubble columns are widely used amongst other equipment due to the absence of moving parts, low maintenance cost, and no wear & tear. It is also efficient in mass transfer and mixing time. Handling and processing of liquids alter the behaviour from Newtonian liquid to non-Newtonian liquid for example in molasses, cooking oil, micro-algae, paint, cornstarch, etc shift of fluid behaviour is seen. Global hydrodynamics factors including gas holdup, mixing time, and mass transfer alter as a result of behavioural changes in the process. The single bubble research is crucial for comprehending this complex phenomenon. In this study, single bubbles are simulated through ANSYS Fluent using the VOF model. Continuum Surface Force (CSF) model is used to treat surface tension. The single bubble study is carried out in Newtonian liquid water (used as a reference liquid) and non-Newtonian shear-thinning liquid Carboxymethyl cellulose (CMC). Terminal velocity, bubble shape, trajectory, molecular viscosity, strain rate, and velocity vectors including streamlines are studied. The results show the decrease in the terminal velocity in water till the bubble diameter is 5 mm and after that velocity increases as a function of bubble diameter. However, in CMC two domains of terminal velocity were observed. In the first domain, the terminal velocity increases up to 4 mm in diameter and after that, it attains a plateau. A zigzag trajectory is seen in water for lower bubble sizes, as the bubble size increases (db > 6 mm) the path becomes linear. Whereas in CMC, the rectilinear trajectory is observed due to higher viscosity for all bubble diameters studied.
Page(s):
0-0
DOI:
DOI not available
Published:
Journal: Sixth International Conference on Sustainability in Process Industries (SPI) 19-20 Octover 2022 (Book of Abstracts), Volume: 0, Issue: 0, Year: 2022
Keywords:
Isolated bubbles
,
Computational fluid dynamics
,
Volume of Fluid
,
Terminal velocity