[Back]

A. Schuster, M. Kozek, B. Voglauer, A. Voigt:
"Modelling of a Viscose-fiber drying process";
Talk: 6th Vienna Mathmod 09, Vienna; 2009-02-11 - 2009-02-13; in: "Proceedings of the 6th Mathmod Vienna 09", Argesim Report, No. 35 (2009), ISBN: 978-3-901608-35-3; Paper ID 225, 7 pages.

A dynamic model of a Through-Air-Drying process for viscose staple fibres was established. In this process fibres are transported through a convective dryer which consists of numerous
rotating drum sieves. Finally the fibres pass through two remoistening drums. The structure of the model is modular and scalable, where one drum is one module. By considering one module to be a unique discrete place, the system of partial differential equations (conservation of mass and energy) turns into a system of ordinary differential equations. Therefore, mean values of parameters and states, also as simulation results, are calculated. Drying rates and heat transfer rates are calculated using phenomenological equations for heat and mass transfer. Kinetics of drying is separated into three stages, where viscose fibres are hygroscopic. For sorption behaviour of the fibres the PEK model is applied. The process model is able to simulate transient behaviour of the dryer like changes of the incoming fibre moisture, changes of the drying air temperature and humidity, and changes of the thickness of the fibre layer on the drums. Simulation results of the longitudinal fibre moisture distribution along the dryer show good accordance with measurement data at different operating points e.g. different temperature profiles.