Numerical Simulation of Gas-Liquid Two-Phase Flow at Various Inlet Positions in Bubble Column at Low Gas Velocity

In order to examine the law of the gas-liquid two-phase flow at various inlet positions of a bubble column, an Euler-Euler two-fluid model coupled with the population balance model (PBM) was used to simulate the effects of four inlets at various positions in the middle of the bubble column bottom on gas-liquid two-phase flow in the bubble column. We verified the mesh of the computational domain and gas hold-up distribution by comparing with experimental data. This study also investigated dynamic behaviours of gas hold-up, bubble number density, liquid horizontal velocity, etc., which provide instructions and basis for the design of the bubble column. The simulated results using an Euler-Euler two-fluid model with PBM were found to be consistent with the experimental results and better than those calculated using an Euler-Euler two-fluid model with single bubble diameter. Furthermore, the dynamic behaviours of gas hold-up, liquid horizontal velocity, distribution of gas hold-up, and vortex strength were all affected by the inlet position. When the inlet was farther from the middle of the bottom of the bubble column, the gas hold-up had an S-shaped distribution and the vortex strength increased; the gas hold-up and bubble plume oscillation period initially increased and then decreased. The bubble number density was not significantly affected by the inlet positions in the bubble column. Moreover, the group with the bubble diameters of 5.95 mm had the largest bubble number density.