Mass Transfer Coefficient Correlations Spreadsheet (Packed Bed, Tray, Spray)

Mass transfer coefficient correlations quantify the rate at which species diffuse across phase boundaries—critical for designing absorbers, strippers, extractors, and reactors. In packed beds, correlations like those of Ramachandran–Chaudhari or Bravo–Fair relate the Sherwood number (Sh) to Reynolds (Re) and Schmidt (Sc) numbers, accounting for packing geometry (e.g., specific surface area, void fraction) and flow regime (laminar to turbulent). For tray (plate) columns, correlations such as O’Connell’s or Chan–Fair’s incorporate weeping, entrainment, and froth dynamics, often using the Murphree tray efficiency framework extended to local mass transfer via liquid- and vapor-phase film coefficients. Spray or droplet-based systems rely on correlations for single-droplet or ensemble behavior (e.g., Calderbank–Moo-Young), where interfacial area generation, droplet size distribution, and relative velocity dominate the Sh–Re–Sc relationship. The spreadsheet integrates these domain-specific models with consistent thermophysical property estimation (e.g., diffusivity via Wilke–Chang or Fuller–Schettler–Giddings), automatic regime identification (e.g., laminar vs. turbulent film), and error-checking logic to ensure physically plausible inputs. It serves not only as a pedagogical tool for teaching transport phenomena but also as a preliminary design aid for process engineers before deploying CFD or rigorous simulation platforms.