Computation of pressure drop for dilute gas–solid suspension across thin and thick orifices

The present work deals with the computation of the gas–solid two-phase flow pressure drop across thin and thick orifices for a vertically downward flow configuration at the higher limits of a dilute phase flow situation (0.01≤α_s,in≤0.10). The Eulerian–Eulerian (two-fluid) model has been used in conjunction with the kinetic theory of granular flow with a four-way coupling approach. The validation of the solution process has been performed by comparing the computational result with the existing experimental data. It is observed that the two-phase flow pressure drop across the orifice increases with an increase in the thickness of the orifice, and the effect is more prominent at higher solid loading. The pressure drop is found to increase with an increase in the solid volume fraction. An increase in the Reynolds number or the area ratio increases the pressure drop. An increase in the size of the particles reduces the pressure drop across the orifice at both small and relatively large solid volume fractions. Finally, a two-phase multiplier has been proposed in terms of the relevant parameters, which can be useful to evaluate the gas–solid two-phase flow pressure drop across the orifice and can subsequently help to improve the system performance.