New experimental data are presented on the coalescence dynamics of twin bubbles at two adjacent nozzles in carboxymethyl cellulose (CMC) solutions. The coalescence process was recorded by using a fast video technique and the images were then analyzed to evaluate the regime, efficiency, and patterns of bubble coalescence. The results reveal that the coalescence process contains the four periods of spherical expansion, rapid mergence, overall growth, and instant departure. The coalescence efficiency always passes through five stages with the gas flow rate; it grows with the CMC solution concentration, but decreases with the surfactant concentration, except at very low gas flow rates. The bubble coalescence pattern strongly depends on the nozzle spacing, but conditionally on the gas flow rate and the solution properties.

中文翻译：

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羧甲基纤维素溶液中并排生长气泡的聚结特性

在羧甲基纤维素（CMC）溶液中，两个相邻喷嘴处的双气泡的聚结动力学提供了新的实验数据。通过使用快速视频技术记录聚结过程，然后分析图像以评估气泡聚结的方式，效率和模式。结果表明，合并过程包含四个阶段的球形扩展，快速合并，整体增长和即时离开。聚结效率始终随气体流量经过五个阶段；它会随着CMC溶液浓度的增加而增长，但随着表面活性剂的浓度而下降，除非在非常低的气体流速下。气泡的聚结模式在很大程度上取决于喷嘴的间距，但有条件地取决于气体的流速和溶液的性质。