Fluid Dynamic Optimization of Flat Sheet Membrane Modules – Movement of Bubbles in Vertical Channels

• Main Authors: L. Bohm, H. Prieske, M. Kraume
• Format: Article
• Language: English
• Published: AIDIC Servizi S.r.l. 2013-06-01
• Series: Chemical Engineering Transactions
• Online Access: https://www.cetjournal.it/index.php/cet/article/view/6645

Fouling is one of the key challenges in the operation of membrane bioreactors. Aeration is a simple but cost-intensive measure to clean the membranes. The aim of this project is to deepen the understanding of the behavior of the bubbles in such geometries to be able to optimize the cleaning of membrane systems and make them more cost-effective. Therefore, with respect to flat sheet membrane modules, the rise of a single bubble in a rectangular channel was investigated experimentally and numerically. The experimental part was performed with a high speed camera and the images were analyzed with the help of NI LabView, Vision Development Module and MS Excel. The software was used to determine the centre of mass of the bubble on each image which provides the rising path when combined. This rising path is determined for different parameter combinations varied bubble sizes and superimposed liquid velocities. The same parameter combinations were investigated numerically with the help of Ansys Fluent. Based on the rising paths, a comparison of the simulation and experiments is possible. Specifically the terminal rise velocity, the oscillation frequency and the amplitude are used for comparison.