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Full-Text Articles in Engineering
Local Gas Holdup In A Draft Tube Airlift Bioreactor, Hu Ping Luo, Muthanna H. Al-Dahhan
Local Gas Holdup In A Draft Tube Airlift Bioreactor, Hu Ping Luo, Muthanna H. Al-Dahhan
Chemical and Biochemical Engineering Faculty Research & Creative Works
Airlift Column Bioreactors Are Gas-Liquid Contact Devices Characterized by a Rising Channel and a Down Flow Channel Due to Gas Holdup Differences in These Two Channels. Local Gas Holdup Distribution Strongly Affects the overall Gas-Liquid Flow Dynamics in Airlift Columns. in This Work, Local Gas Holdup Distributions in a Draft Tube Airlift Column Covering Both Bubbly Flow and Churn-Turbulent Flow Regimes Have Been Studied using Computed Tomography (CT) Technique as Well as Conventional Techniques. the Radial and Axial Evolutions of the Gas Holdup Distribution Will Be Discussed, Together with the Effects of Superficial Gas Velocity and Geometry Parameters. the Obtained …
Local Characteristics Of Hydrodynamics In Draft Tube Airlift Bioreactor, Hu Ping Luo, Muthanna H. Al-Dahhan
Local Characteristics Of Hydrodynamics In Draft Tube Airlift Bioreactor, Hu Ping Luo, Muthanna H. Al-Dahhan
Chemical and Biochemical Engineering Faculty Research & Creative Works
Airlift Column Reactors Have Been Widely Used in Bioprocesses. the Design, Scale-Up, and Performance Evaluation of Such Reactors All Require Extensive and Accurate Information About the Gas-Liquid Flow Dynamics, Particularly as Computational Fluid Dynamics (CFD) Has Become More Popular in the Last Decade. However, Due to the Limitation of Most Conventional Techniques for Gas-Liquid Flow Dynamics Measurement, Only Global Hydrodynamic Parameters (E.g., Cross-Sectionally Averaged Liquid Circulation Velocity, overall Gas Holdup, and overall Mass Transfer Rate) Have Been Extensively Studied. the Local Flow Characteristics (E.g., the Macro-Mixing and the Turbulence Intensity) Remain Unclear. in This Study, We Use the Computer Automated …
Macro-Mixing In A Draft-Tube Airlift Bioreactor, Hu Ping Luo, Muthanna H. Al-Dahhan
Macro-Mixing In A Draft-Tube Airlift Bioreactor, Hu Ping Luo, Muthanna H. Al-Dahhan
Chemical and Biochemical Engineering Faculty Research & Creative Works
Airlift Reactors Are Pneumatically Agitated Reactors that Have Been Widely Used in Industries, Particularly in Bioprocesses. Extensive Studies About the Flow Dynamics in Airlift Column Reactors Exist; However, Most of These Studies Have Focused on Global Hydrodynamic Parameters using Conventional Techniques. the Local Flow Characteristics, such as the Macro-Mixing and the Turbulence Intensity, Are Crucial for Reliable Design and Scale-Up, and They Remain Unclear. This Work Focuses on Studying the Macro-Mixing in a Draft-Tube Airlift Bioreactor Utilizing an Advanced Flow Dynamic Measurement Technique, Computer Automated Radioactive Particle Tracking (CARPT). True Residence Time Distribution Analyses for the overall Column as Well …
Liquid Saturation And Gas-Liquid Distribution In Multiphase Monolithic Reactors, Tobias Bauer, Shaibal Roy, Ruediger Lange, Muthanna H. Al-Dahhan
Liquid Saturation And Gas-Liquid Distribution In Multiphase Monolithic Reactors, Tobias Bauer, Shaibal Roy, Ruediger Lange, Muthanna H. Al-Dahhan
Chemical and Biochemical Engineering Faculty Research & Creative Works
The Monolith Bed is One of the Promising Catalytic Reactors for a Number of Chemical Gas-Liquid-Solid Processes. in the Present Work, Liquid Saturations for Five Different Monoliths Have Been Investigated Experimentally in a Cold-Flow Unit with a Reactor Diameter of 5.0 Cm. the Influences of Gas and Liquid Flow Rates and of the Direction of Two-Phase Flow on Liquid Saturation Were Examined. the Results Indicate that the Direction of Flow Has No Significant Influence on Liquid Saturation for Proper Gas-Liquid Distribution. the Experimental Results Are in Good Agreement with Predictions of the Drift Flux Model using the Distribution Parameter Proposed …
Quantification Of Solids Flow In A Gas-Solid Riser: Single Radioactive Particle Tracking, Satish Bhusarapu, Muthanna H. Al-Dahhan, Milorad P. Dudukovic
Quantification Of Solids Flow In A Gas-Solid Riser: Single Radioactive Particle Tracking, Satish Bhusarapu, Muthanna H. Al-Dahhan, Milorad P. Dudukovic
Chemical and Biochemical Engineering Faculty Research & Creative Works
Solids in Risers of Circulating Fluidized Beds (CFB) Exhibit Local Backflow and Recirculation. Measurement of the Concentration-Time Response to an Impulse Injection of Tracer, Even at Two Elevations Cannot Determine the Residence Time Distribution (RTD) of Solids Uniquely. Hence, Evaluation of RTD in Risers from Conventional Tracer Responses is Difficult and Often Not Possible. in Addition, Estimating the Solids Circulation Rate in These Closed Loop Systems, is a Non-Trivial Problem. in This Work, a Single Radioactive Particle in the CFB Loop is Tracked during its Multiple Visits to the Riser And, by Invoking Ergodicity, Solids Circulation Rate, Accurate Solids RTD …
Liquid Holdup And Pressure Drop In The Gas-Liquid Cocurrent Downflow Packed-Bed Reactor Under Elevated Pressures, Jing Guo, Muthanna H. Al-Dahhan
Liquid Holdup And Pressure Drop In The Gas-Liquid Cocurrent Downflow Packed-Bed Reactor Under Elevated Pressures, Jing Guo, Muthanna H. Al-Dahhan
Chemical and Biochemical Engineering Faculty Research & Creative Works
An Experimental Investigation of the Residence Time Distribution, Liquid Holdup, and Pressure Drop in a Gas-Liquid Downflow Packed Bed Reactor with Porous Particles Operated under Elevated Pressures is Presented. the Effects of the Two-Phase Flow Rates and Reactor Pressures on the External Liquid Holdup and Pressure Drop Are Discussed. a Mechanistic Model, Which Accounts for the Interaction between the Gas and Liquid Phases by Incorporating the Shear and Velocity Slip Factors between Phases, is Employed to Predict the External Liquid Holdup and Pressure Drop for the Experimentally Covered Flow Regime. the Involved Parameters, Such as Shear and Velocity Slip Factors …
A Lagrangian Description Of Flows In Stirred Tanks Via Computer-Automated Radioactive Particle Tracking (Carpt), A. R. Rammohan, A. Kemoun, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic
A Lagrangian Description Of Flows In Stirred Tanks Via Computer-Automated Radioactive Particle Tracking (Carpt), A. R. Rammohan, A. Kemoun, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic
Chemical and Biochemical Engineering Faculty Research & Creative Works
In This Study, Computer-Automated Radioactive Particle Tracking (CARPT) is Implemented for the First Time in the Characterization of Flows in Stirred Tanks. Both the Experimental Set-Up Are Discussed. the CARPT Technique is Seen to Capture Qualitatively Most of the Important Flow Phenomena Observed in Stirred Tank Flows, Like the Two Recirculating Loops above and Below the Impeller and the Dead Zones at the Bottom of the Tank. the CARPT Data is Also Used to Extract ''Sojourn'' Time Distributions in Different Zones of the Reactor. These Distributions Are Used to Partially Quantify the Observed Dead and Active Zones in the Tank. …