Hydrodynamics of a bubble column with phase change

- Bubble column with phase change has been studied using a vapor-water system.
- Hydrodynamics with phase change are very different from that without phase change.
- Axial profile of temperature results in complex condensation and vaporization behaviors.
- Gas holdup has a U-shape axial profile in bubble column with phase change.
- Phase change leads to a much wider bubble size distribution.

The bubble column reactor with phase change are used in some important chemical processes, but its hydrodynamics has not been well studied. In this work, the hydrodynamic behaviors of a bubble column with phase change were experimentally studied using a vapor-water system. The axial profiles of liquid temperature, total and local gas holdups, and bubbles size distribution were measured. The results showed that the hydrodynamics with phase change were very different from that without phase change. The temperature was lower than the liquid boiling point in the bottom region, and this difference decreased with increasing axial height. With phase change, the gas holdup showed a “U” shaped axial profile, while without phase change it showed a flat axial profile. In addition, phase change led to a much wider bubble size distribution. The results were analyzed based on the heat and mass transfer between the gas and liquid phases. These experimental data were valuable for further development of a mathematical model to describe the complex hydrodynamics in a bubble column with phase change.