This paper presents a steady state one-dimensional two-fluid model for gas-solid two-phase flow
in a vertical raiser. The model is solved using conservative variable approach for the gas phase and
fourth order Runge-Kutta method is used for the solid phase. The model predictions for pressure
drop are compared with available experimental data and with Eulerian-Lagrangian predictions and
a good agreement is obtained. The results indicate that the pressure drop increases as the solid
mass flow rate, particle size and particles density increase. In addition, the model predictions for
minimum pressure drop velocity are compared with experimental data from literature and the
mean percentage error, MPE for minimum pressure drop velocity is -9.89%. It is found that the
minimum pressure drop velocity increases as the solid mass flow, particle size and particle density
increase while it decreases as the system total pressure increases.