Liquid Distribution in Industrial Structured-Packed Columns via Gamma-Ray Computed Tomography

A 600-mm diameter test column was constructed and packed with 3 layers of aluminum Sulzer 500Y packing. Liquid maldistribution was studied using a mechanical mechanism for blocking two rows of distributor holes. Two-phase counter-current flow was studied using air and water. Surfactant was added to mimic fluids with low surface tension. Gamma-ray CT scans were performed over a range of liquid and vapor rates, and visualization of flow details with pixel size down to 1mm was demonstrated. Generally, liquid holdup approached a characteristic value moving down the column. The characteristic holdup increased with liquid and/or vapor rates, as expected. When a distributor blocking mechanism was deployed, the decreased liquid fraction in the under-irrigated area is easily detectable in cross-sectional tomographic scans of the topmost packing layer. Liquid holdup data and tomographic images show that liquid distribution recovers substantially from gross maldistribution after three packing layers in water and two layers with surfactant-water.