(55g) Use of Gamma Scan in Obtaining Hydraulic Data for Trayed and Packed Columns

ABSTRACT Gamma ray absorption has been used for troubleshooting operating distillation and absorption columns. In such an application the scan would point to the missing or collapsed trays, or lack of vapor in a space between two trays indicating the flooding condition. FRI does not use gamma scanning for such purpose, but it uses a high strength gamma ray source to determine quantitatively the froth density and liquid holdup in downcomer and on trays as well as the liquid holdups in random and structured packing columns. This paper shows experimental results for froth density profile in a sieve tray downcomer with iso-Butane/ n-Butane system at 11.4, 20.7, and 34.5 bar; and Cyclohexane/Normal heptane at 1.62 bar. The profiles of a straight downcomer and sloped downcomer are also compared.

Key Words: Distillation, sieve tray, gamma scan, froth density profile, liquid holdup, sloped ýdowncomer, straight downcomer.