Airlift reactors are frequently preferred in biochemical engineering, and related investigations are almost performed using bench-scale reactors. However, in industrial-scale reactors, multiphase fluid usually exhibits unique mixing and transfer behaviors. Therefore, we studied the flow regimes characteristics in an industrial-scale center-rising airlift reactor (CRALR) with a diameter of 1.2 m. The results show that the available jet hole area of the gas distributor gradually increases along with the superficial gas velocity in the plateau range of the total pressure drop. Since the rise in initial liquid height enlarges the available jet hole area, the flow regime can be transformed from a pure heterogeneous regime to other regimes. Meanwhile, the total gas holdup plunges within the transition regime range, which can be interpreted by the gas–liquid oscillations in the gas distributor with a large free gas volume. When the oscillations cannot maintain the small bubble ratio, the rapid transition from a homogeneous regime to heterogeneous regime is affected. Compared with previous results, the bubble stream rotates in advance in the homogeneous regime of the industrial-scale CRALR. The rotational structure helps to reduce the flow resistance and improves the radial bubble distribution. Furthermore, the total gas holdup curves under various operating conditions converge into one curve at which a limit, determined by equipment parameters, is ultimately reached in the course of increasing the superficial gas velocity. It turns out that the fluids have similar hydrodynamic behaviors in flow fields of different scales when the limit is reached.

气升式反应器在生化工程中经常受到青睐，相关研究几乎都是使用实验室规模的反应器进行的。然而，在工业规模的反应器中，多相流体通常表现出独特的混合和传递行为。因此，我们研究了直径为 1.2 m 的工业规模中心上升气升反应器 (CRALR) 的流态特性。结果表明，在总压降的平台范围内，气体分布器的可用射孔面积随着表观气速逐渐增大。由于初始液体高度的增加扩大了可用的喷射孔面积，因此流态可以从纯非均质流态转变为其他流态。同时，总含气量在过渡区范围内下降，这可以通过具有大自由气体体积的气体分配器中的气液振荡来解释。当振荡不能保持小气泡比率时，从均质状态到异质状态的快速转变会受到影响。与之前的结果相比，气泡流在工业规模的 CRALR 的均质区域中提前旋转。旋转结构有助于降低流动阻力并改善径向气泡分布。此外，在各种操作条件下的总气体滞留率曲线会聚成一条曲线，在该曲线处，在增加表观气速的过程中最终达到由设备参数确定的极限。事实证明，当达到极限时，流体在不同尺度的流场中具有相似的流体动力学行为。