scholarly journals A Review of Modeling Rotating Packed Beds and Improving Their Parameters: Gas—Liquid Contact

2021 ◽  
Vol 13 (14) ◽  
pp. 8046
Author(s):  
Farhad Ghadyanlou ◽  
Ahmad Azari ◽  
Ali Vatani
Keyword(s):  
Mass Transfer ◽  
Scale Up ◽  
Packed Bed ◽  
Packed Beds ◽  
Transfer Coefficients ◽  
Dimensionless Numbers ◽  
Two Phase ◽  
Shape Factors ◽  
Area Of Interest ◽  
Rotating Packed Bed

The aim of this review is to investigate a kind of process intensification equipment called a rotating packed bed (RPB), which improves transport via centrifugal force in the gas—liquid field, especially by absorption. Different types of RPB, and their advantages and effects on hydrodynamics, mass transfer, and power consumption under available models, are analyzed. Moreover, different approaches to the modeling of RPB are discussed, their mass transfer characteristics and hydrodynamic features are compared, and all models are reviewed. A dimensional analysis showed that suitable dimensionless numbers could make for a more realistic definition of the system, and could be used for prototype scale-up and benchmarking purposes. Additionally, comparisons of the results demonstrated that Re, Gr, Sc, Fr, We, and shape factors are effective. In addition, a study of mass transfer models revealed that the contact zone was the main area of interest in previous studies, and this zone was not evaluated in the same way as packed beds. Moreover, CFD studies revealed that the realizable k-ε turbulence model and the VOF two-phase model, combined with experimental reaction or mass transfer equations for analyzing hydrodynamic and mass transfer coefficients, could help define an RPB system in a more realistic way.

Modelling the Hydrodynamics of Gas-Liquid Packed Beds via Slit Models: A Review

2005 ◽  
Vol 3 (1) ◽  
Author(s):  
Ion Iliuta ◽  
Faical Larachi
Keyword(s):  
Mass Transfer ◽  
Multiphase Flow ◽  
Complex Geometry ◽  
Packed Bed ◽  
Packed Beds ◽  
Reactor Performance ◽  
Two Phase ◽  
Flow Equations ◽  
Considerable Impact ◽  
Transfer Thermodynamics

Packed bed columns are intensively used as multiphase contactors and reactors in chemical, biochemical, and petrochemical industries. Due to two-phase through the packed beds, the performance of multiphase contactors depends on the complex interaction of the interphase mass transfer, thermodynamics and hydrodynamics. Under reaction conditions, the intraparticle mass transfer and reaction kinetics have additional considerable impact on the reactor performance. The inherent complexity of multiphase systems leaves many issues unresolved and leads to many inconsistencies and questionable approximations, especially in the modelling of multiphase flow. Multiphase flow modelling in packed beds is a complicated task because of the difficulty incorporating the complex geometry into the flow equations, and the difficulty in accounting for the gas-liquid interactions in the presence of complex fluid-particle (e.g., partial wetting) contacting. This review focuses on recent advances made in the modelling of the hydrodynamics of two-phase downflow and counter-current flow in packed beds via two-fluid models coupled with slit and double slit phenomenological approximations relating the mutual three phase hydrodynamic interactions.

Experimental and Theoretical Studies on Air Humidification by a Water Spray for Humid Air Turbine Cycle

2006 ◽  
Author(s):  
Zhen Xu ◽  
Yunhan Xiao ◽  
Yue Wang
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Pressure Loss ◽  
Low Cost ◽  
Packed Bed ◽  
Transfer Coefficients ◽  
Humid Air ◽  
Two Phase ◽  
Spray Tower ◽  
Air Turbine

Humidification of compressed air is important for humid air turbine cycle. Earlier studies paid more attention to packed bed towers. However, a spray tower has inherent advantages such as less pressure loss and low cost. In this study, a pressurized model spray tower was established for the experiments. A specially designed air diffuser was installed to achieve uniform air velocity profiles over the cross section and a mist eliminator was used to trap the water droplets in the outlet air. Performance of the tower was tested at different pressures and water/air ratios. Pressure loss was measured and analyzed at different air velocities. A comprehensive analysis of the humidification process in the spray tower was carried out. A mathematical model considering droplet motion and conservation of heat and mass was developed to predict heat and mass transfer in the water droplet-air two-phase flow. Local heat and mass transfer coefficients over height of the tower were calculated. It has been shown that the parameters of outlet air and water can be calculated within a maximal error of 7.3% compared with the experiment results. Droplet size is a main parameter that affects operating performance of the spray tower. It has also been indicated that pressure loss in the spray tower is low and this will benefit its application in HAT.

scholarly journals Effect of Multiple Liquid Inlets on Mass Transfer in Rotating Packed Beds

2020 ◽  
Vol 328 ◽  
pp. 02010
Author(s):  
Jakub Elcner ◽  
Miroslav Jicha
Keyword(s):  
Fluid Dynamics ◽  
Mass Transfer ◽  
Computational Fluid Dynamics ◽  
Packed Bed ◽  
Volume Of Fluid ◽  
Packed Beds ◽  
Liquid Holdup ◽  
Rotating Packed Bed ◽  
Unsteady Rans ◽  
Liquid Distributor

This study deals with optimalization of rotating packed bed design using computational fluid dynamics approach. Comparison of three variants of liquid distributor were performed on 2D geometry. Turbulence was modelled using unsteady RANS approach and volume of fluid technique were used to simulate gas-liquid interphase. Results were compared on basis of liquid holdup evaluation.

Multilevel cross flow rotating packed bed to enhance gas film control mass transfer process

2021 ◽  
Vol 161 ◽  
pp. 108321
Author(s):  
Qing-Qing Duan ◽  
Zhi-Guo Yuan ◽  
You-Zhi Liu ◽  
Shan-Shan Duan ◽  
Xi-Fan Duan
Keyword(s):  
Mass Transfer ◽  
Transfer Process ◽  
Cross Flow ◽  
Mass Transfer Process ◽  
Packed Bed ◽  
Rotating Packed Bed

An Experimental Study of Heat and Mass Transfer During Drying of Packed Beds

1992 ◽  
Vol 114 (3) ◽  
pp. 727-734 ◽  
Author(s):  
W. C. Lee ◽  
O. A. Plumb ◽  
L. Gong
Keyword(s):  
Mass Transfer ◽  
Experimental Study ◽  
Glass Beads ◽  
Drying Rate ◽  
Packed Beds ◽  
Transfer Coefficients ◽  
Model Predictions ◽  
Drying Models ◽  
Surface Saturation ◽  
Drying Conditions

An experimental study has been conducted to provide a data base for drying packed beds of granular, nonhygroscopic materials. Experimental results for drying rate, saturation distribution, temperature distribution, and surface saturation are reported for drying glass beads under carefully documented drying conditions. Capillary pressure for both imbibition and drainage was measured for the glass beads, whose size ranged from 65 μm to 450 μm. The drying results demonstrate that, contrary to available model predictions, porous materials do not necessarily exhibit saturation gradients that always increase with distance from the drying surface. Under certain conditions the capillary potential is sufficient to create an internal drying front. The measurements of surface saturation are the first to be reported. They are utilized to speculate on the reasons for the failure of drying models to compare well with experiment without adjusting the convective heat or mass transfer coefficients.

Sign in / Sign up

Export Citation Format

Share Document