Flow Investigation of Two Phase Flow in Bubble Column \ud Using Particle Image Velocimetry and Image Processing

Bubble size distribution, gas hold up, planar liquid flow field, bubble rise velocity, residence time distribution of bubbles are the key parameters for bubble column design and performance evaluation. Flow visualization and gas-liquid two phase interactions in bubble column can be examined using particle image velocimetry (PIV) as well as image processing techniques. In this work, we present use of flow visualisation and measurement techniques such as PIV and image processing for determining the bubble size distribution (BSD), gas hold-up, planar liquid flow field, bubble rise velocity, residence time distribution of bubbles, trajectories followed by bubble for different surfactant concentration addition, and other parameters in a needle and nozzle sparger of different design in rectangular bubble column for understanding the column hydrodynamics. Particle image velocimetry is widely used technique for investigating the fluid flow in a whole plane, which is non-intrusive where flow-marker or tracer particles are added into the flow and their behaviour is observed. Image processing technique is an effective and appropriate method for the assessment of BSD, bubble rise velocity, residence time distribution of bubbles, bubble trajectory and indirect approximation of gas hold-up up. A 700 x 200 x 57 mm single/multiple needle rectangular bubble column operating a wide range of superficial velocities is used for the investigation