Control of pressurized microbubble generation by multi-channel membranes: Experiments and modeling

Abstract

Microbubbles have been attracting a lot of attention in the fields of chemical and petrochemical engineering, environmental protection, medicine, and aquaculture etc. Herein, a controlled pressurized microbubble generation system is developed. Numerous microbubbles are generated under certain of pressure by multi-channel ceramic membranes in a surfactant-free system consisting of dispersed gaseous and continuous aqueous phases. The average diameter and size distribution of the microbubbles are significantly affected by the membrane pore size, membrane area, liquid viscosity, pressure and gas-liquid flow ratio. A mathematical model about the average diameter of microbubbles is established for the first time by directly introducing the membrane parameters including the membrane area and membrane pore size, and the error of the as-established model is less than 10%. More importantly, the model can be used to predict the optimal membrane pore size and membrane area under different operating conditions under the premise of achieving the expected bubble size. The work will aid the understanding and development of microbubble generation with high performance.