A new quantitative measurement method for mixing and segregation of binary-mixture fluidized bed by capacitance probe

•A new method for mixing or segregation of binary mixtures was developed.•Mixing process of initially segregated binary mixtures was acquired.•Distributions of mixing in binary mixtures fluidized bed were acquired.•Effect of operating condition on mixing of binary mixtures was studied.

Dissimilar solids fluidization is a widely encountered phenomenon in many industrial processes in which the inevitable mixing or segregation phenomenon is very important for reactor design and operation. In this paper, a new quantitative measurement method for mixing and segregation of binary mixtures in bubbling fluidized bed was developed based on capacitance probe. Verification experimental results showed that capacitance probe is a reasonable method for mixing and segregation of binary mixtures. A linear relationship between probe signal and fraction distribution of solids in binary mixtures was found. Transient and steady fluidization experiments of binary mixtures with almost equal size but different densities were conducted. In transient fluidization experiments, the real-time mixing process of initially totally segregated binary solids and finally reached steady mixing state were acquired. The mechanisms of mixing processes in binary mixtures fluidized bed with different density ratios were analyzed. In steady fluidization experiments, the distribution of mixing information in bubbling fluidized bed was acquired and the results showed reasonably good agreement with theories in the literature. In summary, capacitance probe proved to be a useful method in mixing or segregation of binary mixtures fluidization.