Fig. 1. Geometry of a bubble generator
Fig. 2. Experimental setup for visualizing micro bubbly flows
Fig. 3. Images of bubbly flows according to the type of the bubble generator and water flow rate; Qwater = (a) 400 ml/min, (b) 500 ml/min, (c) 600 ml/min
Fig. 4. Area fraction of bubble with respect to liquid phase
Fig. 5. Variations of bubble area fraction according to Reynolds number at the venturi throat
Fig. 6. Bubble size distributions for each type of bubble generator; (a) type 1, (b) type 2,(c) type 3, (d) type 4
Fig. 7. Bubble diameter according to the evaluation methods for each type of bubble generator; (a) type 1, (b) type 2, (c) type 3, (d) type 4
Fig. 8. Variations of bubble diameter according to Reynolds number at venturi throat
Table 1. Design parameters and operation conditions
References
- Agarwal, A., Ng, W. J., Liu, Yu., 2011, "Principle and Applications of Microbubble and Nanobubble Technology for Water Treatment," Chemoshpere, Vol. 84, pp. 1175-1180. https://doi.org/10.1016/j.chemosphere.2011.05.054
- Sadatomi, M., Kawahara, A., Matsuura, H., Shikatani S., 2012, "Micro-Bubble Generation Rate and Bubble Dissolution Rate Into Water by a Simple Multi-Fluid Mixer with Orifice and Porous Tube," Exp. Thermal Fluid Sci., Vol. 41, pp. 23-30. https://doi.org/10.1016/j.expthermflusci.2012.03.002
- Sadatomi, M., Kawahara, A., Kano, K., Ohtomo, A., 2005, "Performance of a New Micro-Bubble Generator with a Spherical Body in a Flowing Water Tube," Exp. Thermal Fluid Sci. Vol. 29, pp. 615-623. https://doi.org/10.1016/j.expthermflusci.2004.08.006
- Gabbard, C., 1972, "Development of a Venturi Type Bubble Generator for Use in the Molten-Salt Reactor Xenon Removal System," ORNL-TM-4122, pp. 1-30.
- Sung, G., Sung, J., Lee, M. H., 2016, "Development and Performance Test of a Micro Bubble Irrigation System for Root Canal Cleaning of Tooth," J. Korean Society of Visualization, Vol. 14, No. 1, pp. 40-45. https://doi.org/10.5407/JKSV.2016.14.1.040
- Baylar, A., Aydin, M. C., Unsal, F., and Ozkan, F., 2009, "Numerical Modeling of Venturi Flows for Determining Air Injection Rates Using FLUENT V6. 2," Math. Comput. Appl., Vol. 14, pp. 97-108.
- Guerra, V. G., Bettega, R., Goncalves, J. A. S., Coury, J. R., 2012, "Pressure Drop and Liquid Distribution in a Venturi Scrubber: Experimental Data and CFD Simulation," Industrial & Eng. Chem. Res. Vol. 51, pp. 8049-8060. https://doi.org/10.1021/ie202871q
- Sung, J., Park, S. M. and Yoo, J. Y., 2004, "Time-Resolved Two-Phase PIV Measurements of Freely Rising Bubble Flows with an Image Separation Method," J. Korean Society of Visualization, Vol. 2, No. 1, pp. 39-45.
- Lau, Y. M., Sujatha, K. T., Gaeini, M., Deen, N. G., Kuipers, J. A. M., 2013, "Experimental Study of the Bubble Size Distribution in a Pseudo-2D Bubble Column," Chem. Eng. Sci., Vol. 98, pp. 203-211. https://doi.org/10.1016/j.ces.2013.05.024