Split‐and‐recombine (SAR) microreactor is an advanced reactor for chemical process intensification. Bubble flow in the SAR microchannel is an important phenomenon that affects reaction efficiency, however drew little attention before. This study aims to explore the underlying mechanisms of bubble splitting, retraction, and breakup behaviors in a compact SAR microchannel. Two breakup flow patterns, unilateral flow and unilateral alternate flow were identified with symmetric or asymmetric splitting, respectively. Mechanism analysis indicates that the splitting symmetry issue is related to liquid slug size, viscous effect and novel retraction behavior of a splitting filament. The retraction is induced by the interconnection and unequal pressures between the splitting filaments. The correlation between normalized breakup time and Ca number confirms the Capillary‐pressure breakup mechanism for the splitting gas filaments. Two empirical correlations for the two breakup flow patterns were proposed, which illustrate the significant contribution of bubble retraction to the breakup degree.

中文翻译：

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分裂复合微通道中气泡的分裂行为及破碎机制


分裂重组（SAR）微反应器是一种用于化学过程强化的先进反应器。 SAR微通道中的气泡流动是影响反应效率的重要现象，但之前很少受到关注。本研究旨在探索紧凑型 SAR 微通道中气泡分裂、回缩和破裂行为的基本机制。两种破碎流模式，单侧流和单侧交替流分别通过对称或不对称分裂来识别。机理分析表明，分裂对称性问题与液塞尺寸、粘性效应和分裂细丝的新颖回缩行为有关。收缩是由分裂细丝之间的互连和不等压力引起的。标准化破裂时间和 Ca 数之间的相关性证实了分裂气体细丝的毛细管压力破裂机制。提出了两种破碎流动模式的两个经验相关性，说明了气泡回缩对破碎程度的显着贡献。