Hydrodynamics of an Airlift Column for Aeration in Molten Sulfur
The airlift column is a promising technology for the removal of volatile gas from high-viscosity molten sulfur. However, a detailed analysis is lacking on the hydrodynamic properties inside the column, due to the difficulty in flow behavior detection in the opaque molten sulfur. In this work, we ado...
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| Format: | Article |
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MDPI AG
2021-12-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/12/1/117 |
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| author | Junjie Wang Xiao Xu Wei Wang Yudong Li Shihan Wu Haiqiang Yang Qiang Yang |
| author_facet | Junjie Wang Xiao Xu Wei Wang Yudong Li Shihan Wu Haiqiang Yang Qiang Yang |
| author_sort | Junjie Wang |
| collection | DOAJ |
| description | The airlift column is a promising technology for the removal of volatile gas from high-viscosity molten sulfur. However, a detailed analysis is lacking on the hydrodynamic properties inside the column, due to the difficulty in flow behavior detection in the opaque molten sulfur. In this work, we adopted the computational fluid dynamics simulation to understand the hydrodynamic behaviors in an airlift column for molten sulfur aeration. In addition, we analyzed the impacts of the superficial gas velocity (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>U</mi><mrow><mi>G</mi><mi>r</mi></mrow></msub></mrow></semantics></math></inline-formula>) and column height on the hydrodynamic characteristics, such as gas holdup, average bubble diameter, and liquid circulation velocity (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>U</mi><mrow><mi>L</mi><mi>r</mi></mrow></msub></mrow></semantics></math></inline-formula>) in the column. The simulation shows that at a constant column height of 15 m, an increase on gas holdup can be obtained with the increase of the superficial gas velocity, while the bubble diameter remains almost constant. Once the superficial gas velocity exceeded 0.333 m/s, the liquid circulation velocity increased slowly. With a variation on the column height from 5 to 25 m, a negligible change on gas holdup, but an obvious increase on liquid circulation velocity and bubble diameter is observed at the given superficial gas velocity of 0.0389 m/s. Furthermore, the simulation shows a similar trend, but with considerably more detailed information, on the relationship between the gas holdup and liquid circulation velocity when compared to the predictions from the Chisti correlation (1988) and an optimized correlation proposed in this work. |
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| language | English |
| last_indexed | 2024-03-10T03:51:36Z |
| publishDate | 2021-12-01 |
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| series | Applied Sciences |
| spelling | doaj.art-be2fa28e1b844007b9eb26eff4ecaa5d2023-11-23T11:07:54ZengMDPI AGApplied Sciences2076-34172021-12-0112111710.3390/app12010117Hydrodynamics of an Airlift Column for Aeration in Molten SulfurJunjie Wang0Xiao Xu1Wei Wang2Yudong Li3Shihan Wu4Haiqiang Yang5Qiang Yang6School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, ChinaSchool of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, ChinaSchool of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, ChinaSchool of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, ChinaSchool of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, ChinaSchool of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, ChinaSchool of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, ChinaThe airlift column is a promising technology for the removal of volatile gas from high-viscosity molten sulfur. However, a detailed analysis is lacking on the hydrodynamic properties inside the column, due to the difficulty in flow behavior detection in the opaque molten sulfur. In this work, we adopted the computational fluid dynamics simulation to understand the hydrodynamic behaviors in an airlift column for molten sulfur aeration. In addition, we analyzed the impacts of the superficial gas velocity (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>U</mi><mrow><mi>G</mi><mi>r</mi></mrow></msub></mrow></semantics></math></inline-formula>) and column height on the hydrodynamic characteristics, such as gas holdup, average bubble diameter, and liquid circulation velocity (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mi>U</mi><mrow><mi>L</mi><mi>r</mi></mrow></msub></mrow></semantics></math></inline-formula>) in the column. The simulation shows that at a constant column height of 15 m, an increase on gas holdup can be obtained with the increase of the superficial gas velocity, while the bubble diameter remains almost constant. Once the superficial gas velocity exceeded 0.333 m/s, the liquid circulation velocity increased slowly. With a variation on the column height from 5 to 25 m, a negligible change on gas holdup, but an obvious increase on liquid circulation velocity and bubble diameter is observed at the given superficial gas velocity of 0.0389 m/s. Furthermore, the simulation shows a similar trend, but with considerably more detailed information, on the relationship between the gas holdup and liquid circulation velocity when compared to the predictions from the Chisti correlation (1988) and an optimized correlation proposed in this work.https://www.mdpi.com/2076-3417/12/1/117internal loop airlift columnmolten sulfurCFD simulationgas holdupbubble diameterliquid circulation velocity |
| spellingShingle | Junjie Wang Xiao Xu Wei Wang Yudong Li Shihan Wu Haiqiang Yang Qiang Yang Hydrodynamics of an Airlift Column for Aeration in Molten Sulfur Applied Sciences internal loop airlift column molten sulfur CFD simulation gas holdup bubble diameter liquid circulation velocity |
| title | Hydrodynamics of an Airlift Column for Aeration in Molten Sulfur |
| title_full | Hydrodynamics of an Airlift Column for Aeration in Molten Sulfur |
| title_fullStr | Hydrodynamics of an Airlift Column for Aeration in Molten Sulfur |
| title_full_unstemmed | Hydrodynamics of an Airlift Column for Aeration in Molten Sulfur |
| title_short | Hydrodynamics of an Airlift Column for Aeration in Molten Sulfur |
| title_sort | hydrodynamics of an airlift column for aeration in molten sulfur |
| topic | internal loop airlift column molten sulfur CFD simulation gas holdup bubble diameter liquid circulation velocity |
| url | https://www.mdpi.com/2076-3417/12/1/117 |
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