Structural Design and Performance of a Jet-Impinging Type Microbubble Generator

Abstract

A jet-impinging type microbubble generator is designed, including a liquid nozzle and a gas nozzle with the disc-baffle closely arranged along the same axis. When the discbaffle diameter is greater than the jet width at the gas nozzle position, the impingement zone and radial wall-jet region are formed, thereby promoting the generation and dispersion of microbubbles. As the dissipation rate in the impingement zone increases, the mean bubble diameter decreases, and the number fraction of microbubbles increases. The bubble radial dispersion width is dependent on the radial wall-jet velocity and the time for the bubble to follow the radial wall-jet. Reducing the surface tension is beneficial to the generation of microbubbles but has little effect on the state or width of the microbubble dispersion. Empirical correlations for predicting the d 32 and dispersion width are proposed, and the relative error is less than 20%. The results show that the jet-impinging type microbubble generator has better energy efficiency than most bubble generating systems reported in the literature.

Performance Evaluation and Scale-up of the Swirl-Venturi Microdroplet Generator

“…Consistent with the conclusion obtained in the previous section, the reduction of the SVMG size is more conducive to energy concentration and improves the mass transfer energy efficiency. In addition, compared with the k L a /( P / V ) index − reported for the gas–liquid system, the energy efficiency value of the SVMG is equivalent or even better.…”

Numerical Simulation of Air–Water–Flake Graphite Triple-Phase Flow Field in a Homemade Double-Nozzle Jet Micro-Bubble Generator

“…They effectively resolve the issue of frequent clogging [13], which has withstood the test of industrial practice and lays the foundation for the industrial application of high-efficiency jet flotation columns. Among them, the jet micro-bubble generator harnesses the vacuum produced by the high-velocity jet to draw in the air as well as crush it into minuscule bubbles, which has the advantages of a smaller bubble diameter, high volume fraction of gas phase, simple structure, and low energy consumption [14,15]. Therefore, the current study on jet micro-bubble generators has become one of the essential study contents of micro-bubble generators.…”