Research On Measure Solid Flow Rate Of Catalytic Cracking Catalysts

In a self-developed and transparent circulating fluidized bed, self-made heat transfer probe was installed. Using FCC catalysts, sand and room air as fluidizing medium, a study on experiment of measure solid flow rate of catalytic cracking catalyst was carried out. Self-made solid flow measuring cylinder which was marked scale was placed in exit of riser in order to measure solid flow. Study that the fluid flow rate affected probe temperature affecting radial distance. Investigated probe heating power, sand particle size on radial distance of the probe temperature. In dense phase conveying and diluted phase conveying, respectively, the impact of parameters such as probe heating power, solid flow rate, bed density and sand particle size on surface temperature of probe and heat transfer coefficient was fully investigated. By using dimensional analysis theory, heat balance theory and a series of hypothesis that experimental results fixed, a mathematical model of solid-phase flow measurement in the circulating fluidized bed was founded, and then the solving was carried out.The results showed that the solid phase flow rate was small, the existence of the probe radial temperature region, while the solid phase flow rate increased, the probe radial temperature region disappeared; sand particle size, the probe heating power effected radial distance of the probe temperature very small; wind velocity didn't effect surface temperature of probe and heat transfer coefficient; in diluted phase conveying, heat transfer coefficient increased with the rise of probe heating power, solid flow rate and bed density, but decreased with the rise of sand particle size; surface temperature of probe decreased with the rise of solid flow rate and bed density and rised with the increase of probe heating power and sand particle size; in dense phase conveying, heat transfer coefficient rised with the increase of probe heating power, solid flow rate and bed density, and decreased with the rise of sand particle size; surface temperature of probe decreased with the increase of solid flow rate and bed density and rised with the increase of probe heating power and sand particle size; heat transfer coefficient of FCC was bigger than heat transfer coefficient of sand; surface temperature probe of sand was higher than surface temperature probe of FCC. The calculated value from the established mathematical model of solid-phase flow measurement in the circulating fluidized bed had given a good agreement with the results from the experiment with the largest error no more than 10 percent.