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Article
Experiments and Modelling on Electrochemically generated bubbly flows.
| Authors: |
Wedin, R., Cartellier, A., Davoust, L., Byrne, P. |
| Document Type: |
Article |
| Pubstate: |
Accepted |
| Journal: |
Proceedings of the 4th ICMF, New Orleans 2001. |
| Volume: |
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| Year: |
2001 |
AbstractDespite a large demand in the area of electrochemical processes, e.g., the production of chemicals such as chlorine, caustic soda and sodium chlorate, the available literature on the flows of micro bubbles is limited. An experimental investigation of micro bubbles two-phase flows has therefore been undertaken. The experiments were performed within a vertical pipe (inner diameter 50mm). An original electrochemical bubble generator has been specially designed for this study. The liquid phase is a salt solution, which inhibits coalescence, so that the electrochemically generated hydrogen bubbles exhibit typical diameters about 100 micron, corresponding to a particle Reynolds number about unity. Both the void fraction and the velocity of the micro bubbles were measured through image analysis. Velocity measurements were also performed using a new type of sensor, based on mono-modal fibre-optics. The void fraction distribution was found to significantly differ from existing results obtained at higher bubble to pipe diameters ratios. The experimental measurements are also compared with numerical simulations based on a 2-D drift flux model. Finally, the experimental results of the paper demonstrate that the use of Faraday´s law is questionable as regards its ability to predict the input gas flow rate.
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