scholarly journals Retracted: Power Consumption, Mixing Time, and Oxygen Mass Transfer in a Gas-Liquid Contactor Stirred with a Dual Impeller for Different Spacing

2017 ◽  
Vol 2017 ◽  
pp. 1-1
Keyword(s):  
Mass Transfer ◽  
Power Consumption ◽  
Mixing Time ◽  
Oxygen Mass Transfer

scholarly journals Power Consumption, Mixing Time, and Oxygen Mass Transfer in a Gas-Liquid Contactor Stirred with a Dual Impeller for Different Spacing

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Hayder Mohammed Issa
Keyword(s):  
Mass Transfer ◽  
Power Consumption ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Mixing Time ◽  
Oxygen Mass Transfer ◽  
System A ◽  
Phase Water ◽  
Pharmaceutical Production ◽  
Slight Alteration

Multiple or dual impellers are widely implemented in stirred contactors used in various biological processes like fermentation, water treatment, and pharmaceutical production. The spacing between impellers is considered as a crucial factor in designing of these types of contactors resulting in variation of oxygen mass transfer, mixing time, or power consumption for such biological system. A study of three parts was conducted to characterize the effect of the spacing between impellers on the most important parameters that related to biological contactor performance: oxygen mass transfer coefficientklafrom the gas phase (air) to the liquid phase (water), mixing time, and power consumption for different operating rotational speeds (1.67–3.33 rps) and for three different spacing positions. The used impellers system in the study is a dual impeller system which consists of an inverted and bladed rotated cone (IBRC) and a pitched-blade up-flow propeller (PBPU). The experimental results showed that the shorter spacing (the lower PBPU in a higher position) is more convenient, as the achieved oxygen mass transfer coefficient has showed an improvement in its values with lower mixing time and with a slight alteration in power consumption.

scholarly journals CFD-Based and Experimental Hydrodynamic Characterization of the Single-Use Bioreactor XcellerexTM XDR-10

2022 ◽  
Vol 9 (1) ◽  
pp. 22
Author(s):  
Diana Kreitmayer ◽  
Srikanth R. Gopireddy ◽  
Tomomi Matsuura ◽  
Yuichi Aki ◽  
Yuta Katayama ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Mixing Time ◽  
Vortex Formation ◽  
Operating Conditions ◽  
Impeller Speed ◽  
Oxygen Mass Transfer ◽  
Hydrodynamic Conditions ◽  
Single Use ◽  
Selection Of ◽  
Surface Vortex

Understanding the hydrodynamic conditions in bioreactors is of utmost importance for the selection of operating conditions during cell culture process development. In the present study, the two-phase flow in the lab-scale single-use bioreactor XcellerexTM XDR-10 is characterized for working volumes from 4.5 L to 10 L, impeller speeds from 40 rpm to 360 rpm, and sparging with two different microporous spargers at rates from 0.02 L min−1 to 0.5 L min−1. The numerical simulations are performed with the one-way coupled Euler–Lagrange and the Euler–Euler models. The results of the agitated liquid height, the mixing time, and the volumetric oxygen mass transfer coefficient are compared to experiments. For the unbaffled XDR-10, strong surface vortex formation is found for the maximum impeller speed. To support the selection of suitable impeller speeds for cell cultivation, the surface vortex formation, the average turbulence energy dissipation rate, the hydrodynamic stress, and the mixing time are analyzed and discussed. Surface vortex formation is observed for the maximum impeller speed. Mixing times are below 30 s across all conditions, and volumetric oxygen mass transfer coefficients of up to 22.1 h−1 are found. The XDR-10 provides hydrodynamic conditions which are well suited for the cultivation of animal cells, despite the unusual design of a single bottom-mounted impeller and an unbaffled cultivation bioreactor.

Effect of Biomass Concentration on Oxygen Mass Transfer, Power Consumption, Interfacial Tension and Hydrodynamics in a Multiphase Partitioning Bioreactor

energyo ◽  
2019 ◽  
Author(s):  
Manuel Alejandro Lizardi-Jiménez ◽  
Pedro López-Ordáz ◽  
Margarita Mercedes González-Brambila ◽  
Andrea Linares-Morales ◽  
Rodrigo Melgarejo-Torres
Keyword(s):  
Mass Transfer ◽  
Interfacial Tension ◽  
Power Consumption ◽  
Biomass Concentration ◽  
Oxygen Mass Transfer ◽  
Partitioning Bioreactor

Effect of Biomass Concentration on Oxygen Mass Transfer, Power Consumption, Interfacial Tension and Hydrodynamics in a Multiphase Partitioning Bioreactor

2018 ◽  
Vol 16 (10) ◽  
Author(s):  
Manuel Alejandro Lizardi-Jiménez ◽  
Pedro López-Ordáz ◽  
Margarita Mercedes González-Brambila ◽  
Andrea Linares-Morales ◽  
Rodrigo Melgarejo-Torres
Keyword(s):  
Mass Transfer ◽  
Power Consumption ◽  
Droplet Size ◽  
Scale Up ◽  
Biomass Concentration ◽  
Multiphase System ◽  
Oxygen Mass Transfer ◽  
Dispersed Phase ◽  
Transfer Coefficients ◽  
Partitioning Bioreactor

Abstract Several studies have reported that the hydrodynamics are not affected by the biomass in multiphase partitioning bioreactors. This work aims to demonstrate the effect of biomass concentration (0, 1, 3 and 5 g L−1) on the oxygen mass transfer coefficients, the droplet size of the dispersed phase, power consumption and superficial tension in a multiphase partitioning bioreactor (ionic liquid-aqueous-air-biomass system). At a biomass concentration of 5 g L−1, the oxygen mass transfer coefficient (kLa) increased by 55% (249 h−1) compared with the abiotic system (160 h−1). In the multiphasic system, the droplet size (d32) decreased when the biomass concentration was increased, producing an increment in the mass transfer area of the dispersed phase. In addition, the power consumption decreased by 44 % compared to a previous report without biomass. Furthermore, the increment of biomass concentration decreased the superficial tension by up to 15 %. A biomass increment in a multiphase system not also increases product yield, but also enhances the bioconversion process. The results obtained suggest that it is obligatory to consider the effect of biomass concentration on hydrodynamic characterisation, design, scale-up and optimisation for improving the performance of biotechnological processes using multiphase bioreactors.

Correlation of oxygen mass transfer and power consumption in an aeration system by a rotating cone

2018 ◽  
Vol 125 ◽  
pp. 105-111
Author(s):  
Takahiro Adachi ◽  
Toshiki Kubo ◽  
Koji Higashiono ◽  
Mitsuharu Terashima ◽  
Yutaro Takahashi
Keyword(s):  
Mass Transfer ◽  
Power Consumption ◽  
Oxygen Mass Transfer ◽  
Aeration System ◽  
Rotating Cone

scholarly journals Two-Phase Flow Mass Transfer Analysis of Airlift Pump for Aquaculture Applications

Fluids ◽  
2021 ◽  
Vol 6 (6) ◽  
pp. 226
Author(s):  
Rashal Abed ◽  
Mohamed M. Hussein ◽  
Wael H. Ahmed ◽  
Sherif Abdou
Keyword(s):  
Mass Transfer ◽  
Oxygen Transfer ◽  
Transfer Rate ◽  
Two Phase Flow ◽  
Oxygen Transfer Rate ◽  
Flow Patterns ◽  
Oxygen Mass Transfer ◽  
Phase Flow ◽  
Two Phase ◽  
Airlift Pump

Airlift pumps can be used in the aquaculture industry to provide aeration while concurrently moving water utilizing the dynamics of two-phase flow in the pump riser. The oxygen mass transfer that occurs from the injected compressed air to the water in the aquaculture systems can be experimentally investigated to determine the pump aeration capabilities. The objective of this study is to evaluate the effects of various airflow rates as well as the injection methods on the oxygen transfer rate within a dual injector airlift pump system. Experiments were conducted using an airlift pump connected to a vertical pump riser within a recirculating system. Both two-phase flow patterns and the void fraction measurements were used to evaluate the dissolved oxygen mass transfer mechanism through the airlift pump. A dissolved oxygen (DO) sensor was used to determine the DO levels within the airlift pumping system at different operating conditions required by the pump. Flow visualization imaging and particle image velocimetry (PIV) measurements were performed in order to better understand the effects of the two-phase flow patterns on the aeration performance. It was found that the radial injection method reached the saturation point faster at lower airflow rates, whereas the axial method performed better as the airflow rates were increased. The standard oxygen transfer rate (SOTR) and standard aeration efficiency (SAE) were calculated and were found to strongly depend on the injection method as well as the two-phase flow patterns in the pump riser.

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