The application of digital image analysis to study the characteristic of bubble size distribution produced by orifice type microbubble generator

摘要

The use of microbubble has grown massively in many fields such as petrochemical industry and waste water treatment. This phenomenon offers some advantages since such as the ability to provide larger liquid-gas surface contact area. In order to achieve in depth understanding related to those phenomena, some of the measurement methods can be applied such as a capillary suction probe, conductivity probes, and, Phase Doppler Anemometry. The present work was conducted to determine the characteristic of microbubble size distribution by using digital image analysis. The orifice type microbubble generator is set on a rectangular transparent glass box to support the visualization study. The air and water flow observed in this present study were set on 0.1 - 1 lpm and 30 - 80 lpm respectively. Each sequence image was processed using MATLAB. Some steps, including image filtering and image complement, is utilized to produce binary image. In addition, watershed method has also been applied in order to separate the merge bubble to produce an accurate measurement. As a result, the effect of gas and liquid flow rate on the bubble size distribution can be revealed. Finally, it can be concluded that the digital image analysis is a useful and potential technique to study the characteristics of microbubble phenomena.