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Measurements of Local Instantaneous Convective Heat Transfer in a Pipe - Single and Two-phase Flow
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A New Statistical Parameter for Identifying the Main Transition Velocities in Bubble Columns.
Stoyan Nedeltchev1, Swapna Rabha1, Uwe Hampel2
1Helmholtz-Zentrum Dresden-Rossendorf Dresden, Germany.
Chemical Engineering & Technology
|August 30, 2016
Summary
A new statistical parameter, "relative maximum number of visits in a region," accurately identifies flow regime boundaries in bubble columns. This aids in understanding mixing and transfer processes for improved industrial applications.
Area of Science:
- Fluid dynamics
- Chemical engineering
- Multiphase flow systems
Background:
- Flow regimes in bubble columns significantly impact mixing, mass, and heat transfer.
- Accurate identification of flow regime boundaries is crucial for process optimization.
Purpose of the Study:
- To introduce a novel dimensionless statistical parameter for identifying flow regime boundaries in bubble columns.
- To analyze the effectiveness of this new parameter using experimental data.
Main Methods:
- Measurements were conducted in bubble columns using conductivity wire-mesh sensors at high sampling frequencies.
- An air/deionized water system was employed under ambient conditions.
- A new parameter, 'relative maximum number of visits in a region,' was derived from gas holdup time series data.
Main Results:
- The 'relative maximum number of visits in a region' parameter effectively distinguishes between different flow regimes.
- This parameter is derived from the analysis of gas holdup fluctuations.
Conclusions:
- The developed statistical parameter offers a reliable method for flow regime identification in bubble columns.
- This advancement can lead to better control and efficiency in industrial processes involving bubble columns.
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