A solids mixing rate correlation for small scale fluidized beds

作     者：S.Gorji-Kandi S.M.Alavi-Amleshi N.Mostoufi 

作者机构：Department of Chemical EngineeringIran University of Science and Technology School of Chemical EngineeringCollege of EngineeringUniversity of Tehran 

出 版 物：《Particuology》 (颗粒学报（英文版）)

年 卷 期：2015年第13卷第4期

页      面：55-64页

核心收录：

学科分类：080706[工学-化工过程机械] 08[工学] 0807[工学-动力工程及工程热物理] 080102[工学-固体力学] 0801[工学-力学（可授工学、理学学位）] 

基　　金：This paper was prepared with funding from the Ministry of Business  Innovation and Employment contract C10X1006. We also wish to acknowledge funding for CLUES from the Ministry of Business  Innovation and Employment (contract C10X1006 and predecessors  Envirolink Fund  Crown Research Institute core funding) the Ministry for the Environment and Ministry for Primary Industries 

主　　题：Fluidized bed Solids mixing Tracer Digital image processing Mixing index Mixing rate 

摘      要：A new first degree solids mixing rate is proposed to evaluate the mixing of solids in small scale Iluidized beds. Particle mixing experiments were carried out in a 2D fluidized bed with a cross-section of 0.02 m × 0.2 m and a height of Im. white and black particles with average diameters of 850 and 450 μm were used in our experiments. Image processing was used to measure the concentration of the tracers at different times. The effects of four representative operating parameters （superficial gas velocity, ratio of tracer particles to bed particles, tracer particle position, and particle size） on mixing are discussed with reference to the mixing index. We found that the Lacey index depends on the concentration of the tracers, The position of the tracers affects the initial mixing rate but not the final degree of mixing. However, the new mixing rate equation does not depend on the initial configuration of the particles because this situation is considered to be the initial condition. Using the data obtained in this work and that found in literature, an empirical correlation is proposed to evaluate the mixing rate constant as a function of dimensionless numbers （Archimedes, Reynolds, and Froude） in small scale fluidized beds. This correlation allows for an estimation of the mixing rate under different operating conditions and for the detection of the end point and/or the time of mixing.