Hydrodynamic similarity of particle flow behavior in the fully developed region of upward gas-solid CFB riser was experimentally investigated.The experiments were carried out in a 15.1 m high and 100 mm i.d. CFB riser with FCC catalyst particle

and the axial pressure gradients

local solids holdups and particle velocities were measured over a wide range of operating conditions. Through extensive analysis and comparison of particle flow behavior

it was found that the cross-sectional average solids holdups in the fully developed region changed linearly with the number group of (Gs/ρp)1.2/U2.0g

although Gs and Ug showed different effects on particle flow.It was also showed that with different operating conditions

if the value of (Gs/ρp)1.2/Ug2.0 was the same

the local solids holdups

particle descending velocities

solids concentrations inside cluster and cluster frequencies displayed the same spatial distributions

respectively.The research indicated that the number group(Gs/ρp)1.2/U2.0g makes the effects of Gs and Ug combined

and with the same (Gs/ρp)1.2/U2.0g

the particle flow behavior in the fully developed zone of upward gas-solid two-phase flow exhibited very similar micro and macro hydrodynamic characteristics.