Evaluation of pressure drop and mass-transfer characteristics of a structured packing for production and separation of food flavours. Part I: Pressure drop characteristics

Structured packings are attractive candidates for food flavour processing by distillation, as their high capacity and low pressure drop allow ready operation under vacuum. Flooding and pressure drop characteristics of a typical packing are presented. Measurements were carried out with air/water in a column of 0.1 m in diameter packed to a height of 1 m with the structured packing. The experimental data were compared with correlations available in the literature, such as the Sherwood-Leva-Eckert (SLE) (McCabe et al., 1993) generalized pressure drop curves, the Kister and Gill (1992) generalized pressure drop curves for structured packing, GPDC(SP), the Wallis (1969), and derived Lockett (1995) correlations. A packing factor of 280 m-1 gave the best fit to the SLE generalized correlation, within + 20%, while the GPDC(SP) of Kister and Gill (1992) showed deviations of + 30% and + 10% for a constant packing factor of 69 m-1, and a variable factor A = B - C x In X, where X is the flow parameter. The Lockett correlation which uses the specific area of the packings as a scale factor, showed deviations of + 10% only. A Wallis form correlation fitted the best results within +2%.