Bed Expansion in the Dense Phase of Binary Mixture Particle in Gas-Solid Fluidized Beds

Using directly mixing the low temperature spent catalyst with high temperature regenerated catalyst of heavy oil fluidized catalytic cracking,a new combined fluidized-bed regenerator for process of clean gasoline production has been brought forward to solve the energy unbalance caused by the low yield of coke on the catalyst. The bed expansion in the dense phase of binary mixture particle was studied experimentally in a large scale cold model of Perspex experimental equipment withΦ500 mm×12500 mm;and then the effects of gas superficial velocity,bed aspect ratio and mass fraction of fine particle on bed expansion of binary mixture particle were investigated.The results show that the bed expansion coefficient based on voidage decreases with the decrease of bed aspect ratio;when mass fraction of fine particle is about 0.4,the bed expansion coefficient reaches a minimum. Based on the analysis of experimental data,a mathematical model of bed expansion coefficient of binary mixture particle was established,and the calculated values are in good agreement with that of the experimental.