Multiscale Investigations of Reactive Bubble Blows

反应性气泡吹制的多尺度研究

• 批准号: 256646572
• 负责人: Professor Dr.-Ing. Mark Werner Hlawitschka
• 金额: --
• 依托单位: Lehrstuhl für Thermische Verfahrenstechnik (TVT)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/256646572?language=en
• 关键词: Multiscale; Investigations; Reactive; Bubble; Blows

Bubble columns are widely used in chemical, petrochemical, biochemical and metal industry. Especially in reactive bubble columns, the efficiency is influenced by the local hydrodynamics. To increase the efficiency of any apparatus, the mutual interaction of the local hydrodynamics and chemical reactions must be considered, which is not covered by the state-of-the-start integral design methods. However, local description of hydrodynamics by CFD exists, but there are still some challenges to overcome when a coupling with local reaction conditions has to be established:1. Influence of the bubble interaction onto the reaction 2. Influence of the bubble size on bubble behavior 3. Mutual interaction of reaction and hydrodynamics at high time and space resolution (bubble induced turbulence)As given in literature, individual phenomena were isolated investigated by experiments and numerical studies, but the interaction of these phenomena were mainly neglected. In this research project, a new multi-scale experimental and numerical approach is used. Initially the start is with well described test systems followed by the industrial relevant (organic) systems defined in the progress of the SPP.In a first step, experiments in a test cell (<500µl) will be performed with a high spatial and time resolution to investigate the effect of bubble interactions (bouncing, film drainage) on the mass transfer and reactions. Furthermore, experiments in a Venturi cell allow hydrodynamics and reaction investigations of an isolated monodisperse bubble swarm (<10 bubbles) being spatially captured by the counter-current flow. Finally, experiments in a 2D bubble column (polydisperse) will be performed, mimicking a real cylindrical bubble column. The influence of the hydrodynamics and the reactions will be measured taking into account the local bubble size by optical probes. The hydrodynamics and turbulence are resolved by laser based measurement techniques (PIV, LIF, PDA) and is the basis for code validation.For the reactive bubble interactions, a mesh free solver (FPM) is used, which is able to track the interface without reconstruction. Hence, it can resolve the reactions at any location close to the interface and will support the experimental description at hydrodynamic stress of single and swarm bubbles on the reaction close to the interface. The modeling of a large-scale apparatus is then based on the Euler-Euler model to keep the computational costs low. Based on the experimental results, a turbulence model will be selected and optimized. The implementation of the pH- and temperature dependent reactions allows a first description and detailed analysis of the reactive bubble column.The result of the project will lead to a better understanding of the mutual influence of hydrodynamics and reaction on different scales. The numerical investigations will therefore increase the accuracy of layout and reduce efforts for time and cost intensive pilot experiments.

鼓泡塔广泛应用于化工、石化、生化和金属工业。特别是在反应泡罩塔中，效率受到局部流体动力学的影响。为了提高任何装置的效率，必须考虑局部流体动力学和化学反应的相互相互作用，而这一点并未被最新的整体设计方法所涵盖。然而，CFD 对流体动力学的局部描述是存在的，但在必须建立与局部反应条件的耦合时，仍然存在一些需要克服的挑战：1．气泡相互作用对反应的影响 2. 气泡尺寸对气泡行为的影响 3. 高时间和空间分辨率下反应和流体动力学的相互作用（气泡引起的湍流） 如文献中所述，通过实验和数值研究来单独研究个别现象，但主要忽略了这些现象的相互作用。在这个研究项目中，使用了一种新的多尺度实验和数值方法。最初是从详细描述的测试系统开始，然后是 SPP 进展中定义的工业相关（有机）系统。第一步，将以高空间和时间分辨率在测试池（<500μl）中进行实验，以研究气泡相互作用（弹跳、薄膜排水）对传质和反应的影响。此外，文丘里池中的实验允许对逆流在空间上捕获的孤立的单分散气泡群（<10 个气泡）进行流体动力学和反应研究。最后，将在二维鼓泡塔（多分散）中进行实验，模拟真实的圆柱形鼓泡塔。将通过光学探针考虑局部气泡尺寸来测量流体动力学和反应的影响。流体动力学和湍流通过基于激光的测量技术（PIV、LIF、PDA）来解决，并且是代码验证的基础。对于反应气泡相互作用，使用无网格求解器（FPM），它能够跟踪界面而无需重建。因此，它可以解析靠近界面的任何位置的反应，并将支持单个气泡和群气泡在靠近界面的反应的流体动力应力下的实验描述。然后，大型设备的建模基于 Euler-Euler 模型，以保持较低的计算成本。根据实验结果，将选择并优化湍流模型。 pH 和温度相关反应的实施可以对反应泡罩塔进行首次描述和详细分析。该项目的结果将有助于更好地理解不同规模的流体动力学和反应的相互影响。因此，数值研究将提高布局的准确性，并减少时间和成本密集型试点实验的工作量。