分布器对鼓泡塔中气泡直径分布的影响

采用电导探针测定了冷态鼓泡塔中不同气速下的气泡直径及气含率的轴向分布,考察了分布板对鼓泡塔操作性能的影响.结果表明:随着开孔率的减小,从均匀鼓泡区到过渡区的转变提前;在均匀鼓泡区,开孔率对气泡直径影响较小;在过渡区,开孔率大的分布器形成的稳定气泡直径较小、气含率较大;分布板开孔直径越大,形成的初始气泡直径越大,但对轴向气泡直径分布的影响仅限于分布器区.包含分布器影响的气泡直径经验关联式为d/D=140.2Bo-0.5Ga-0.12Fr0.099(h/D)-0.15T-0.34(0.5 cm/s＜ug＜7 cm/s).

Effect of Gas Distributor on Bubble Size Profiles in A Bubble Column

Axial bubble size distribution and gas holdup profiles were determined under the ambient temperature and pressure using the dual electrical conductivity probes technology in a gas-liquid bubble column, and the effects of the gas distributor on the performance of the bubble column were researched. The results indicated that the regime transfer was delayed when the open area increased. The effects of the open area on the bubble size distribution were discussed for operating in two flow regimes: homogeneous regime and transition regime. The maximal stable bubble diameter was decreasing and gas hold-up increasing when the open area was increasing in transition regime while the effect was neglected in homogeneous regime. The initial bubble diameter was increasing when orifice diameter increased, whose effect is limited to the distribution regime. An empirical correlation which took into account the effect of the gas distributor to predict the time averaged bubble diameter was derived and it is also found to be in good agreement with the experiment data.