Mass transfer of rising gas bubbles in reacting liquids

上升气泡进入反应液体的传质

• 批准号: 256647858
• 负责人: Professor Dr.-Ing. Matthias Kraume
• 金额: --
• 依托单位: Fachgebiet Verfahrenstechnik
• 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 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/256647858?language=en
• 关键词: Mass; transfer; rising; gas; bubbles

The idea of this project is the investigation of the influence of the interaction of bubbles on the mass transfer in reactive bubbly flows. Previously, the experimental work was focused on the determination of the interaction between fluid dynamics, mass transfer and chemical reaction. As in practical applications multiple bubbles interact, here certain bubbles in different types of bubble formations will be investigated. The experimental systems developed in the first funding period will further be used for complementary single bubble experiments. These experiments provide the necessary basic information to evaluate the results of interacting bubble formations.The aim of the complementary single bubble investigations is the determination of mass transfer coefficients. These are determined based on the change of the bubble size during the bubble's contact with the (reacting) liquid phase. The experiments are performed in two apparatuses which were further developed in the first funding period. The apparatuses are a bubble ascent channel and a counter current flow cell.Varied parameters are: The chemical system (WG Klüfers/Schindler/Herres-Pawlis), bubble size, contact time between bubble and liquid, pressure, temperature, educt concentration in the liquid phase.The results will be mathematically modeled with adjusted or new Sherwood correlations while reasonably incorporating all influencing parameters. These correlations will be used to compare systems with more complex velocity and concentration fields in the vicinity of the bubble. These fields will be created under controlled conditions. Several approaches will be tested. A chain of bubbles, an array of bubbles and a bubble swarm which will be stopped with a single bubble following will be investigated. For comparison, turbulence promoters which were developed and investigated in the first funding period by other groups in the priority program will be tested as well (WG Kähler/Schlüter/Thoeming). Besides the investigation of the chemical systems de-veloped in the first funding period, the new and further developed systems with parallel and/or consecutive chemical reactions will be investigated. In some cases, this requires new ap-proaches in the experiments to be able do an accurate quantification. The fully automated ex-perimental apparatuses will be equipped with new stationary and moving spectral measurement techniques (WG Rinke/Simon). This approach has great potential as chemical reactions are developed which have competing chemical reactions resulting in differing discolorations.The chosen approach of following the bubble during its ascent with an optical measurement technique provides results of the rising path, bubble shape and shrinkage behavior under diverse controlled conditions. This information is of high interest for numerically working groups as it can easily be used for validation (WG Bothe/Rzehak/Sommerfeld).

本研究的主要目的是探讨反应泡状流中气泡间的相互作用对传质的影响。以前，实验工作主要集中在确定流体动力学，传质和化学反应之间的相互作用。由于在实际应用中多个气泡相互作用，这里将研究不同类型的气泡形成中的某些气泡。在第一个资助期内开发的实验系统将进一步用于补充单气泡实验。这些实验为评价相互作用气泡形成的结果提供了必要的基本信息。补充的单气泡研究的目的是确定传质系数。这些是基于气泡与（反应）液相接触期间气泡尺寸的变化来确定的。实验在第一个资助期进一步开发的两个装置中进行。实验装置为气泡上升通道和逆流流动池，实验参数包括：化学体系（WG Klüfers/Schindler/Herres-Pawlis）、气泡尺寸、气泡与液体的接触时间、压力、温度、液相中离析物浓度，实验结果将采用调整后的或新的舍伍德关联式进行数学建模，同时合理地考虑所有影响参数。这些相关性将被用来比较系统更复杂的速度和浓度场附近的气泡。这些字段将在受控条件下创建。将对几种方法进行测试。将研究气泡链、气泡阵列和将被单个气泡跟随而停止的气泡群。为了进行比较，优先计划中的其他小组在第一个资助期内开发和研究的湍流促进器也将进行测试（WG Kähler/Schlüter/Thoeming）。除了研究在第一个供资期内被淘汰的化学系统外，还将研究具有平行和/或连续化学反应的新的和进一步开发的系统。在某些情况下，这需要新的实验方法才能进行准确的定量。全自动实验设备将配备新的固定和移动光谱测量技术（WG Rinke/Simon）。这种方法具有很大的潜力，因为化学反应的发展具有竞争性的化学反应，导致不同的discoloration.The选择的方法，以下气泡在其上升过程中的光学测量技术提供的上升路径，气泡形状和收缩行为的结果在不同的控制条件下。这些信息对于数值工作组来说非常重要，因为它可以很容易地用于验证（WG Bothe/Rzehak/Sommerfeld）。