High‐frequency formation of bubble with short length in a capillary embedded step T‐junction microdevice

Abstract The performances of slug flow gas–liquid reactors are mostly determined by slug length, especially for the high gas–liquid flow rate ratio condition. This work is the first time to report the short bubble generated with high frequency in a capillary embedded step T‐junction microdevice. The aspect ratio of bubble could be around 0.5 with a frequency higher than 750 s −1 when the gas–liquid flow rate ratio is even higher than 5. The specific surface area of the generated gas–liquid microdispersion system is larger than 10,400 m 2 /m 3 . The short bubble formation process includes two periods, and its formation mechanism is mainly because of the relatively higher pressure drop in the step T‐junction, which provides a much higher breakup force for the squeezing flow. Finally, two models are developed to predict the bubble frequency and volume. This work provides a highly promising dispersion technology for the gas–liquid process intensification in microreactors.