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

作　　者：Kang Yu WeijieWang Tao Zhang Yumei Yong Chao Yang 

机构地区：[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

出　　处：《Chinese Journal of Chemical Engineering》2019年第10期2273-2283,共11页中国化学工程学报（英文版）

基　　金：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 Petro China.

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 and6.0 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.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 and6.0 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 

分 类 号：TK12[动力工程及工程热物理—工程热物理]