Mass Transfer Modelling in Counter-Current Crossed Flows in an Industrial Extractor

A new mathematics model is developed for counter-current crossed (CCC) flows of the porous media and miscela applied in an industrial extractor ‘Rotocell’. There are considered: oil diffusion in extraction field, mass transfer between pore and bulk phases, influence of trays, existence of drainage and loading zones, the variation of the viscosity and density of miscela, oil losses and the transient operational regime. The coupled mathematical model is composed of partial differential equations and ordinary differential equations with boundary conditions that link the percolation sections, the trays, the drainage and loading zones in outline of the CCC flows. The calculation algorithm is based on the method of lines. Different from the method of multi-stages, the new model is sensitive to changes in raw material characteristics, section sizes and wagon parameters. The new model also presents the spatial concentration distributions of pore and bulk phases in the extraction field.