Experimental study on breakup of a single bubble in a stirred tank: Effect of gas density and liquid properties

Abstract

Bubble breakup plays an important role in gas–liquid flows, but detailed studies are still scarce. In this work, the breakup behavior of a single bubble in a stirred tank was experimentally studied with a high‐speed camera, focusing on the effect of gas density, liquid properties, agitation speed, and mother bubble size. The bubble breakup time, breakup probability, breakup rate, and daughter bubble size distribution were determined. The internal‐flow phenomenon that the gas flowed from the smaller part to the larger part of a deformed mother bubble was observed by a high‐speed camera. The results showed that with increasing gas density, agitation speed, mother bubble size and decreasing surface tension, the bubble breakup rate and probability of equal‐size distribution significantly increased. With increasing liquid viscosity, the bubble breakup rate decreased especially in the high viscosity range. An M‐shaped daughter bubble size distribution was observed, which was consistent with our previous bubble breakup model.

Marangoni effect on hydrodynamics and mass transfer behavior in an internal loop airlift reactor under elevated pressure

“…This is due to two opposite effects of pressure on the gas holdup of small bubbles. On one hand, the elevated pressure reduces the internal flow in deformed bubbles, which enhances the bubble breakup and then increases the gas holdup of small bubbles 57 . Moreover, this enhancing effect intensifies with an increase in bubble size 17 .…”

“…On one hand, the elevated pressure reduces the internal flow in deformed bubbles, which enhances the bubble breakup and then increases the gas holdup of small bubbles. 57 Moreover, this enhancing effect intensifies with an increase in bubble size. 17 In ethanol-water system, the probability of bubble coalescence is reduced due to Marangoni stress, leading to a notable increase of smaller bubbles, thus a low rate of bubble breakup.…”

Experimental study on the differences between bubble and drop breakages in agitated turbulent flows

“…To verify these models, a large number of experimental data on fluid particle breakage are required. Several studies have reported experiments of breakage frequency and DSD for bubble and drop, respectively 12,22–42 (summarized in Tables S3.1 and S3.2). Some experiments showed that the breakage frequency monotonically increased with increasing fluid particle size 12,23–30 .…”

“…Several studies have reported experiments of breakage frequency and DSD for bubble and drop, respectively 12,22–42 (summarized in Tables S3.1 and S3.2). Some experiments showed that the breakage frequency monotonically increased with increasing fluid particle size 12,23–30 . However, the non‐monotonic trend was also observed.…”

Gas-liquid flow regimes and effective interfacial area in a solid foam block stirred tank

“…Mechanical agitation is the most common method to enhance mixing/ mass transfer in industries [1,2]. It refers to forcing fluids flow in a vessel by mechanical means, or to the random distribution of two or more separate phases between one another, e.g., by mixing two miscible liquids, dissolving a solid in a liquid, and dispersing a gas in a liquid to form fine bubbles [3,4]. These processes are commonly used in chemical engineering processes including hydrogenation, polymerization, crystallization, fermentation, wastewater treatment, etc.…”