Mechanism and fundamental models of gas-liquid surging for valve columns

The gas-liquid streams in valve columns are likely to surge at low gas velocities, which degrades tray performances and threatens production safety. Therefore, the gas-liquid surging mechanism and vibration properties were investigated in this article. First, the theory of gas-liquid unstable flow at the seal point was proposed based on the principle of lowest energy. Then, the evolution mechanism, gas-liquid flow characteristics, and essential condition of surging are proposed. Meanwhile, experiments were carried out in a phi 580 mm valve column; the frequency spectral and hydraulic characteristics of surging were in accordance with the expected surging mechanism. Moreover, the surging vanish point criterion and safe operating superficial gas velocity for valve columns were advanced. Finally, fundamental models for surging frequency and amplitude were established. The models are in close accordance with the experimental data, which suggests that they could accurately describe the surging behavior.