By means of optical fiber probe

the jet streaming phenomenon in FCC baffle-free strippers was studied in a large cold-model experimental unit. Its properties as well as its development with bed height were studied. A newly developed computational particle fluid dynamics (CPFD) model was further used to explore this phenomenon. Jet streaming mainly happened near the stripper wall

resulting in serious non-uniformity in circumferential solids distribution. The strength of jet streaming decreased with increasing bed height. CPFD model could successfully predict the existence of jet streaming in this system. Although the predicted jet streaming strengths at higher bed heights were slightly overestimated

its trend with increasing bed height qualitatively agreed with the experimental fact. The deeper understanding acquired in this study can be used as a good reference for design and troubleshooting of the industrial FCC strippers.