Experimental characterization of gas-liquid transport processes in a reacting bubble column using a neutralization reaction

使用中和反应对反应泡罩塔中的气液传输过程进行实验表征

• 批准号: 256661637
• 负责人: Dr.-Ing. Katharina Zähringer
• 金额: --
• 依托单位: Institut für Strömungstechnik und Thermodynamik
• 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/256661637?language=en
• 关键词: Experimental; characterization; gas; liquid; transport

The transport of CO2 from the gas phase (bubbles) into a slightly basic watery phase is used to investigate in a quantitative manner mass transfer in a bubble column, first considering the limit case of a fast neutralization reaction. This simple system is appropriate to optimize the complex experimental process. Additionally, it is possible in this manner to deliver early during the first phase of this project experimental data that can be used for validation and comparison by numerical partners within the SPP. The evolution of the pH is followed in space and time in the experiment using indicators (e.g., Uranin) and Laser-Induced Fluorescence (LIF). Thanks to a calibration and knowing the gas conditions at inflow and outflow, it is possible to measure in this manner mass transfer. In order to avoid shadows, light refraction and reflection due to the bubbles, a second, pH-independent tracer is used, allowing to correct the experimental images (2-Color-LIF). The measurement procedure is used first for isolated bubbles and bubble trains, then for small groups of bubbles, varying flow rates and typical bubble diameters. After optimizing the measurement tech-niques, a typical bubble swarm is finally considered. Using high-speed cameras it is possible to track in time bubble diameters, bubble pathlines and mass transfer. Particle Tracking Velocimetry (PTV) is used to measure bubble velocities and trajectories, based on the available experience in our group. Velocities of the liquid phase are measured by Particle Imaging Velocimetry (PIV). Using a stereo-PIV system, all three velocity components of the water phase can be acquired. It is possible in this manner to quantify the impact of hydrodynamics on mass transfer, delivering comparison data for numerical projects within the SPP. Since liquid properties play a considerable role concerning mass transfer, liquid viscosity and surface tension will be varied using different glycerine/water mixtures of known properties. Here again, mass transfer and hydrodynamics will be measured simultaneously.All experimental data will be made available as soon as possible to all project partners and to the entire research community through a database accessible on the Web. All people interested by comparisons and validations of numerical simulations can freely use those experimental results.

CO2从气相（气泡）到稍微碱性的水相的运输被用于以定量的方式研究在鼓泡塔中的传质，首先考虑快速中和反应的极限情况。该系统结构简单，适用于复杂实验过程的优化。此外，还可以通过这种方式在本项目第一阶段的早期提供实验数据，供SPP内的数字合作伙伴用于验证和比较。在实验中使用指示剂（例如，激光诱导荧光（LIF）。由于校准并知道流入和流出时的气体条件，因此可以以这种方式测量质量传递。为了避免由于气泡引起的阴影、光折射和反射，使用了第二种与pH无关的示踪剂，允许校正实验图像（2-Color-LIF）。测量程序首先用于孤立的气泡和气泡串，然后用于小气泡组，变化的流速和典型的气泡直径。在对测量技术进行优化后，最终考虑了一个典型的气泡群。使用高速摄像机可以及时跟踪气泡直径、气泡轨迹和质量传递。基于本课题组已有的实验经验，采用粒子跟踪测速法（PTV）测量气泡的速度和轨迹。液相的速度通过粒子成像测速法（PIV）测量。使用立体PIV系统，可以获得水相的所有三个速度分量。通过这种方式可以量化流体力学对传质的影响，为SPP内的数值项目提供比较数据。由于液体性质在传质方面起着相当大的作用，因此使用不同的已知性质的甘油/水混合物将改变液体粘度和表面张力。在这方面，质量转移和流体力学也将同时进行测量，所有实验数据将通过可在网上查阅的数据库尽快提供给所有项目伙伴和整个研究界。所有对数值模拟的比较和验证感兴趣的人都可以自由地使用这些实验结果。