CFD simulation of gas and solids mixing in FCC strippers
CFD simulation of gas and solids mixing in FCC strippers
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DOI：
10.1002/aic.12646
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发表时间：
2012-04
期刊：
影响因子：
3.7
通讯作者：
Yingjie Liu;Xingying Lan;Chunming Xu;Gangxiao Wang;Jinsen Gao
中科院分区：
文献类型：
--
作者：
Yingjie Liu;Xingying Lan;Chunming Xu;Gangxiao Wang;Jinsen Gao
采用计算流体力学模拟方法，研究了带内装和不带内装的催化裂化汽提塔内的气固混合情况。采用欧拉-欧拉双流体模型和改进的Gidaspow阻力模型对气固流动特性进行了模拟。首先进行了网格独立性研究和二维与三维仿真对比。利用停留时间分布模型和轴向分散模型，得到了气体和固体的平均停留时间、无因次方差和Peclet数等反映反混合程度的参数。此外，还分析了气泡尺寸和气固两相流动分布对气泡与乳化液之间传质的影响。结果表明：v型挡板汽提塔内挡板能有效地促进气固混合，降低气固反混程度，加强气泡与乳液相之间的传质，从而提高汽提效率。©2011美国化学工程师学会，2012
The gas and solid mixing in fluid catalytic cracking strippers with and without internals were investigated using computational fluid dynamics simulations. The Eulerian–Eulerian two-fluid model coupled with the modified Gidaspow drag model was used to simulate the gas-solid flow behavior. The grid independency study and the comparison of 2D and 3D simulations were carried out first. The residence time distribution model and axial dispersion model were utilized to obtain the parameters indicating the back-mixing degree, such as mean residence time, dimensionless variance and Peclet number of gas and solids. Moreover, the influence of bubble size and gas/solid flow distribution on the mass transfer between the bubble and emulsion phase were also analyzed. The results show that the baffles in the V-baffle stripper can efficiently enhance the gas and solids mixing, reduce the back-mixing degree of gas and solids, strengthen the mass transfer between the bubble and emulsion phase, and hence improve the stripping efficiency. © 2011 American Institute of Chemical Engineers AIChE J, 2012