Investigation of the drying characteristics of pressed sugar beet pulp in superheated steam - part 1.

摘要

Steam driers can be used for thermal beet pulp drying after mechanical dewatering, in which the drying takes place in superheated steam under pressure. Aside from new driers, this entails partial or total renewal of the power equipment of a sugar factory. Until now, steam driers have been built and operated based on experience, but research now focuses on their optimization by identifying the sorption equilibria and drying kinetics according to the steam parameters. Sorption isobars are available for pressures of 1-4 bar and temperatures of 100-200deg C. Measurements are easily adjusted by reference to adsorption isotherms (Brunauer, Emmet and Teller equations). Drying tests were carried out in this pressure and temperature range with flow velocitiesof 0.5-2.0 m/s, resulting in dimension-less heat transfer coefficients depending on the chosen experimental parameters. A model of the drying kinetics of beet pulp was constructed for the entire humidity range, the validity of which was confirmed by measurements on a technical drier.