(4c) Gamma Scan and CAT-Scan Data From a Distillation Column At Various Loadings

Rare, and possibly first-of-a-kind, gamma scanning of a distillation column produced some interesting and important results.  While FRI’s 4-foot diameter High Pressure Test Column contained a 10 foot bed of Raschig-Jaeger random packing with a 2-stage liquid distributor and operating with the C6/C7 system at 23.5psia, the column was conventionally scanned several times from top to bottom.  The column was baseline scanned when it was dry and was scanned at 45, 79, 100, and 102% of the Maximum Useful Capacity of the packing.  Distributor liquid levels derived from the scan data were compared against liquid level data from FRI bubblers.  Additionally, CAT-scans were performed at two different column elevations.  At each elevation, 81 data points through the bed of packing were recorded:  9 scanning source positions with 9 different detector positions for each source position around the column circumference.  Mathematical processing of the CAT-scan data was one of the challenges of the project.  Appreciable new knowledge was gained regarding liquid holdup and liquid flow patterns in random packed columns.