Power input is an important engineering and scale‐up/down criterion in stirred bioreactors. However, reliably measuring power input in laboratory‐scale systems is still challenging. Even though torque measurements have proven to be suitable in pilot scale systems, sensor accuracy, resolution, and errors from relatively high levels of friction inside bearings can become limiting factors at smaller scales. An experimental setup for power input measurements was developed in this study by focusing on stainless steel and single‐use bioreactors in the single‐digit volume range. The friction losses inside the air bearings were effectively reduced to less than 0.5% of the measurement range of the torque meter. A comparison of dimensionless power numbers determined for a reference Rushton turbine stirrer (NP = 4.17 ± 0.14 for fully turbulent conditions) revealed good agreement with literature data. Hence, the power numbers of several reusable and single‐use bioreactors could be determined over a wide range of Reynolds numbers between 100 and >104. Power numbers of between 0.3 and 4.5 (for Re = 104) were determined for the different systems. The rigid plastic vessels showed similar power characteristics to their reusable counterparts. Thus, it was demonstrated that the torque‐based technique can be used to reliably measure power input in stirred reusable and single‐use bioreactors at the laboratory scale.

中文翻译：

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在实验室规模的常规和一次性搅拌生物反应器中开发一种可靠的功率输入测量方法

功率输入是搅拌生物反应器中重要的工程和放大/缩小标准。然而，在实验室规模系统中可靠地测量功率输入仍然具有挑战性。尽管扭矩测量已被证明适用于中试规模系统，但传感器精度、分辨率和轴承内相对较高摩擦水平的误差可能成为较小规模的限制因素。在本研究中，通过专注于单位数体积范围内的不锈钢和一次性生物反应器，开发了功率输入测量的实验装置。空气轴承内部的摩擦损失有效降低到扭矩计测量范围的0.5%以下。为参考 Rushton 涡轮搅拌器确定的无量纲功率数的比较 (NP = 4.17 ± 0. 14 完全湍流条件）显示与文献数据非常吻合。因此，可以在 100 和 >104 之间的广泛雷诺数范围内确定几个可重复使用和一次性使用的生物反应器的功率数。为不同系统确定了介于 0.3 和 4.5 之间的幂数（对于 Re = 104）。刚性塑料容器与可重复使用的容器表现出相似的功率特性。因此，证明了基于扭矩的技术可用于可靠地测量实验室规模的搅拌式可重复使用和一次性生物反应器中的功率输入。为不同的系统确定了 5（对于 Re = 104）。刚性塑料容器与可重复使用的容器表现出相似的功率特性。因此，证明了基于扭矩的技术可用于可靠地测量实验室规模的搅拌式可重复使用和一次性生物反应器中的功率输入。为不同的系统确定了 5（对于 Re = 104）。刚性塑料容器与可重复使用的容器表现出相似的功率特性。因此，证明了基于扭矩的技术可用于可靠地测量实验室规模的搅拌式可重复使用和一次性生物反应器中的功率输入。