Investigation of Bubble Characteristics by Photographic Method

The majority of industrial operating units come into contact with two gas and liquid phases. Various methods have been used to determine bubble characteristics over the last few years. In the present study the bubble charactistics have been studied by the shadowgraphy method under the low light condition and the overall mass transfer coefficient have been determined in different pressures and flows. The study has been done in an industrial scale by scrubbers that remove hydrogen fluoride (HF). Using the RLI (reflected LED image) of circularly organized LED light sources created on the bubble surface in low-light situations, a new method for measuring the diameter of the bubble is provided. A system for absorbing gas bubbles by liquid phase has been designed in this project. An image analysis method and empirical relations were used to investigate the mass transfer and hydrodynamic behavior in the wake of single air bubbles rising. The overall properties of the bubble, including the size, shape, path, rising velocity, and mass transfer coefficient of a single bubble were studied and measured using these methods. The investigation was carried out in different liquids using a 0.15 × 0.15 × 0.35 m3 bubble column and nozzles with the diameters of 0.5, 1, 1.5, 2, 2.5 mm. The results show that increasing the diameter of the nozzle increases the diameter of the bubble, resulting in a decrease in velocity. Furthermore, increasing the viscosity of the liquid phase indeed causes the diameter of the bubble to increase while decreasing the velocity. So, based on these findings, we can conclude that the diameter of the bubble is affected by the physical properties of the fluid and has a direct relationship with the diameter of the nozzle.