Authors: Hongliang Xiao a, Yongmin Zhang a, Junwu Wang b, c, d
a State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China
b State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, P.O. Box 353, Beijing 100190, China
c School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
d Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing 100190, China
Source: This paper was published in Chemical Engineering Science, Volume 246.
Abstract: Cross-correlation algorithm has been widely used in experimental measurement of solids velocity. However, its reliability and validation range remain unquantified. To this end, a CFD-based “virtual error quantification” method was proposed to quantify the reliability of cross-correlation algorithm in the measurement of solids velocity in two different gas fluidization regimes, i.e., bubbling and fast fluidization regimes (BFB and FFB). It was found that the cross-correlation algorithm works quite well in the core region of FFB, but its applications in the annulus region of FFB and in BFB should be considered with great caution. Finally, the findings were delineated by solids convection-mixing mechanism based on the relative standard deviation (RSD) of solids velocity signals and solids Péclet number. The present study highlights the deficiency of the cross-correlation based solids velocity measurement in fluidization systems and addresses the need to develop better measurement methods for solids mixing dominated systems.