Investigation of Bubble Size Distributions in Oscillatory Flow at Various Flow Rates

The demand for eco-friendly technologies for industrial processes is increasing. Various factors such as labour costs, exploitation and waste management influences the production costs and hence the profit generated. The water treatment industry is one example of a well-developed sector which is facing these concerns. Microbubble techniques exhibit many benefits which make them applicable to heterogeneous processes, such as longer contact time and greater surface area giving higher mass transfer rates. The Fluidic Oscillator (FO) is a relatively new device which enhances the efficacy of microbubble generation. The FO produces smaller bubbles by applying oscillatory flow through a diffuser to generate microbubbles. This paper aims to study the influence of steady and oscillatory flow to bubble size distribution. The experimentation was carried out with a ceramic diffuser to produce microbubbles in water. A High Speed Camera was used for bubble imaging. Data on bubble distributions at various flow rates was obtained by image post-processing. It was observed that the application of the FO at selected operational conditions gave narrower bubble size distributions in a range of flow rates compared to continuous flow. The range of applications of this technology is continuously increasing.