Effects of internals on phase holdup and backmixing in a slightlyexpanded-bed reactor with gas-liquid concurrent upflow

doi:10.1016/j.cjche.2019.05.011

中国化学工程学报 ›› 2019, Vol. 27 ›› Issue (10): 2273-2283.DOI: 10.1016/j.cjche.2019.05.011

• Fluid Dynamics and Transport Phenomena • 上一篇下一篇

Effects of internals on phase holdup and backmixing in a slightlyexpanded-bed reactor with gas-liquid concurrent upflow

Kang Yu^1,2, Weijie Wang^1,2, Tao Zhang³, Yumei Yong¹, Chao Yang^1,2

1 CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
2 School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China;
3 PetroChina Petrochemical Research Institute, Beijing 102206, China

收稿日期:2018-10-09 修回日期:2019-04-07 出版日期:2019-10-28 发布日期:2020-01-17
通讯作者: Yumei Yong, Chao Yang
基金资助:
Supported by the National Key Research and Development Program (2016YFB0301701), the National Natural Science Foundation of China (21776283, 21427814), Key Research Program of Frontier Sciences of CAS (QYZDJ-SSW-JSC030), the Instrument Developing Project of Chinese Academy of Sciences (YZ201641) and PetroChina.

Effects of internals on phase holdup and backmixing in a slightlyexpanded-bed reactor with gas-liquid concurrent upflow

Kang Yu^1,2, Weijie Wang^1,2, Tao Zhang³, Yumei Yong¹, Chao Yang^1,2

1 CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
2 School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China;
3 PetroChina Petrochemical Research Institute, Beijing 102206, China

Received:2018-10-09 Revised:2019-04-07 Online:2019-10-28 Published:2020-01-17
Contact: Yumei Yong, Chao Yang
Supported by:
Supported by the National Key Research and Development Program (2016YFB0301701), the National Natural Science Foundation of China (21776283, 21427814), Key Research Program of Frontier Sciences of CAS (QYZDJ-SSW-JSC030), the Instrument Developing Project of Chinese Academy of Sciences (YZ201641) and PetroChina.

摘要/Abstract

摘要： Five different internals were designed, and their effects on phase holdup and backmixing were investigated in a gas-liquid concurrent upflow reactor where the spherical alumina packing particles of three diameters (3.0, 4.5 and 6.0 mm) were slightly expanded under the conditions of varied superficial gas velocities (6.77×10^-2-3.61×10^-1 m·s^-1) and superficial liquid velocities (9.47×10^-4-2.17×10^-3 m·s^-1). The experimental results show that the gas holdup increases with the superficial gas velocity and particle size, opposite to the variational trend of liquid holdup. When an internal component is installed amid the upflow reactor, a higher gas holdup, a less liquid holdup and a larger Peclet number characterizing the weaker backmixing are obtained compared to those in the bed without internals under the same operating conditions. Additionally, the minimal backmixing is observed in the reactor equipped with the internals with a novel multi-step design. Finally, empirical correlations were proposed for estimating gas holdup, liquid holdup and Peclet number with the relative deviations within 11%, 12% and 25%, respectively.

关键词: Internals, Phase holdup, Backmixing, Slightly-expanded-bed reactor, Multiphase flow, Hydrodynamics

Abstract: Five different internals were designed, and their effects on phase holdup and backmixing were investigated in a gas-liquid concurrent upflow reactor where the spherical alumina packing particles of three diameters (3.0, 4.5 and 6.0 mm) were slightly expanded under the conditions of varied superficial gas velocities (6.77×10^-2-3.61×10^-1 m·s^-1) and superficial liquid velocities (9.47×10^-4-2.17×10^-3 m·s^-1). The experimental results show that the gas holdup increases with the superficial gas velocity and particle size, opposite to the variational trend of liquid holdup. When an internal component is installed amid the upflow reactor, a higher gas holdup, a less liquid holdup and a larger Peclet number characterizing the weaker backmixing are obtained compared to those in the bed without internals under the same operating conditions. Additionally, the minimal backmixing is observed in the reactor equipped with the internals with a novel multi-step design. Finally, empirical correlations were proposed for estimating gas holdup, liquid holdup and Peclet number with the relative deviations within 11%, 12% and 25%, respectively.

Key words: Internals, Phase holdup, Backmixing, Slightly-expanded-bed reactor, Multiphase flow, Hydrodynamics

Kang Yu, Weijie Wang, Tao Zhang, Yumei Yong, Chao Yang. Effects of internals on phase holdup and backmixing in a slightlyexpanded-bed reactor with gas-liquid concurrent upflow[J]. 中国化学工程学报, 2019, 27(10): 2273-2283.

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Effects of internals on phase holdup and backmixing in a slightlyexpanded-bed reactor with gas-liquid concurrent upflow

Effects of internals on phase holdup and backmixing in a slightlyexpanded-bed reactor with gas-liquid concurrent upflow

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