(131f) Separation Column Gamma Scans - Moving into a New Dimension

Gamma Scans are widely used to diagnose separation column hydraulics both in research settings and at commercial installations. Columns containing packing as well as trays are routinely studied with gamma scans. Typical gamma scan data is presented in graphical form in a plot of scan distance or column elevation versus radiation intensity. The radiation intensity measured is the amount of radiation passing through the column from the scanning radiation source on one side of the vessel to the radiation detector located on the opposite side of the vessel. The radiation intensity is an implicit measure of the process density between the radiation source and detector.

Using the results from gamma scans aid in diagnosing the hydraulic condition of operating separation columns. Differences in measured radiation intensity show how the liquid-vapor is behaving inside the column. Comparing these results to how the liquid-vapor should be acting, given the internals installed, allows for hydraulic issues to be diagnosed.

Recent developments have enhanced the usefulness of the basic gamma scan results by deriving calculated process densities from the gamma scan data. The methodology, the limitations and the realistic benefits of these calculations will be presented. Case studies from both research and commercial environments will be discussed.