Phasengrenzflächen in Blasenströmungen — Teil 2: Großblasen und Pfropfen

In the first part of this article an equation was derived for calculation of the specific interfacial are and the size distribution of bubbles in bubble flow. However, its application is limited to gas contents lower than 12%. At higher gas contents, large bubbles and gas plugs occur in the field of flow. These have a very low interfacial area per unit volume compared to small bubbles. Since large bubbles and gas plugs contain a large proportion of the gas in the flow, the overall interfacial area is reduced. In the present contribution, the gas content above which large bubbles and gas plugs occur is calculated. The results are subjected to experimental testing for vertical pipe flow. In addition, the volume fraction of the larger bubbles is calculated and the results verified experimentally by measurements in bubble columns. Subsequently, the specific enterfacial area with and without large bubbles is calculated for high gas contents. The results are in agreement with values measured for bubble columns and column plates.