Analyzing the effect of using axial impellers in large-scale bioreactors,Biotechnology and Bioengineering

当前位置： X-MOL 学术 › Biotechnol. Bioeng. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Analyzing the effect of using axial impellers in large-scale bioreactors
Biotechnology and Bioengineering ( IF 3.5 ) Pub Date : 2022-06-24 , DOI: 10.1002/bit.28163
Sören Bernauer _{1,

2} , Philipp Eibl _{3,

4} , Christian Witz ₄ , Johannes Khinast ₃ , Timo Hardiman _{1,

5}

Affiliation

In high-performance industrial fermentation processes, stirring and aeration may account for significant production costs. Compared to the widely applied Rushton impellers, axial-pumping impellers are known to yield a lower power draw and at the same time improve mixing. However, their lower gas dispersion capability requires stronger agitation, compromising these benefits. Diverse advanced impeller forms have been developed to cope with this challenge. We apply alternating radial and axial impellers and demonstrate strong gas dispersion and energy-efficient mixing for the first time in a large-scale (160 m³) bioreactor, based on experimental and computational fluid dynamics simulation data. For equal operating conditions (stirrer speed, aeration rate), this setup yielded similar gas hold-ups and better mixing times (35%) compared to a classical Rushton-only configuration. Hence, applying a radial impeller on an upper level for improving gas dispersion maintains the benefits of axial impellers in terms of reducing energy demand (up to 50%). We conclude that this effect is significant only at large-scale, when bubbles substantially expand due to the release of the hydrostatic pressure and have time to coalesce. The work thus extends current knowledge on mixing and aeration of large-scale reactors using classical impeller types.

中文翻译：

分析在大型生物反应器中使用轴向叶轮的效果

在高性能工业发酵过程中，搅拌和曝气可能会导致大量生产成本。与广泛应用的 Rushton 叶轮相比，已知轴向泵送叶轮产生较低的功率消耗并同时改善混合。然而，它们较低的气体分散能力需要更强的搅拌，从而损害了这些优势。已经开发出多种先进的叶轮形式来应对这一挑战。我们应用了交替的径向和轴向叶轮，并首次在大规模（160 m ³) 生物反应器，基于实验和计算流体动力学模拟数据。对于相同的操作条件（搅拌器速度、曝气率），与经典的仅 Rushton 配置相比，这种设置产生了相似的气体滞留率和更好的混合时间 (35%)。因此，在上层应用径向叶轮以改善气体分散保持了轴向叶轮在降低能源需求方面的优势（高达 50%）。我们得出的结论是，这种效应仅在大规模时才显着，当气泡由于静水压力的释放而大幅膨胀并有时间聚结时。因此，这项工作扩展了当前关于使用经典叶轮类型的大型反应器的混合和曝气的知识。

更新日期：2022-06-24

点击分享查看原文

点击收藏

公开下载

阅读更多本刊最新论文本刊介绍/投稿指南11