The particle residence time distribution (RTD) and axial dispersion coefficient are key parameters for the design and operation of a pressurized circulating fluidized bed (PCFB). In this study

the effects of pressure (0.1-0.6 MPa)

fluidizing gas velocity (2-7 m·s

-1

)

and solid circulation rate (10-90 kg·m

-2

·s

-1

) on particle RTD and axial dispersion coefficient in a PCFB are numerically investigated based on the multiphase particle-in-cell (MP-PIC) method. The details of the gas-solid flow behaviors of PCFB are revealed. Based on the gas-solid flow pattern

the particles tend to move more orderly under elevated pressures. With an increase in either fluidizing gas velocity or solid circulation rate

the mean residence time of particles decreases while the axial dispersion coefficient increases. With an increase in pressure

the core-annulus flow is strengthened

which leads to a wider shape of the particle RTD curve and a larger mean particle residence time. The back-mixing of particles increases with increasing pressure

resulting in an increase in the axial dispersion coefficient.