Aerated stirred tank bioreactors are one of the most commonly used systems in various processes such as biofermentation where ensuring adequate mass transfer rate is the sole purpose. In this study, the crucial role of the central impeller type (including Rushton turbine, pitched blade turbine, elephant ear impeller and their combinations) on the performance of an aerated bioreactor equipped with two central impellers and an anchor on the local and overall volumetric mass transfer coefficient was investigated at a variety of operating conditions such as non-Newtonian solution concentrations, and central and anchor impeller speeds. Carboxymethyl cellulose (CMC) solution was used as a power-law fluid. Through the use of electrical resistance tomography, simplified dynamic pressure method, and computational fluid dynamics, several aspects of the aerated coaxial mixer namely local and overall gas holdup and mass transfer were studied. The local mass transfer coefficients were measured using three dissolved oxygen sensors installed at three various heights of the bioreactor. The local gas holdup was also measured using tomography. The results showed the positive effect of the anchor impeller on the mass transfer coefficient up to 10 rpm for different coaxial mixing configurations with various impeller type combinations and CMC concentrations. Among different impeller types, the system with two Rushton turbines resulted in the highest volumetric mass transfer coefficient, which was attributed to the higher gas holdup provided by this configuration as well as the flow pattern generated by the coaxial mixer. Moreover, the local distribution of gas holdup and mass transfer coefficient demonstrated a reduction in both parameters from the bottom to the top of the bioreactor.

曝气搅拌釜生物反应器是各种过程（例如生物发酵）中最常用的系统之一，其中确保足够的传质速率是唯一目的。在这项研究中，中央叶轮类型（包括 Rushton 涡轮、斜叶片涡轮、象耳叶轮及其组合）对配备两个中央叶轮和局部和整体体积质量的锚的曝气生物反应器性能的关键作用在各种操作条件下研究了传递系数，例如非牛顿溶液浓度、中心和锚式叶轮速度。羧甲基纤维素 (CMC) 溶液用作幂律流体。通过使用电阻层析成像、简化的动态压力方法和计算流体动力学，研究了曝气同轴混合器的几个方面，即局部和整体气体滞留量和传质。使用安装在生物反应器三个不同高度的三个溶解氧传感器测量局部传质系数。还使用断层摄影术测量了局部气体滞留量。结果表明，对于具有各种叶轮类型组合和 CMC 浓度的不同同轴混合配置，锚式叶轮对高达 10 rpm 的传质系数产生积极影响。在不同的叶轮类型中，带有两个 Rushton 涡轮机的系统产生了最高的体积传质系数，这归因于这种配置提供的更高的气体保持率以及同轴混合器产生的流动模式。而且，