Affiliation:
1. Valmet AB Sundsvall Sweden
2. Department of Fibre and Polymer Technology Royal Institute of Technology Stockholm Sweden
3. Department of Chemistry and Chemical engineering Chalmers University of technology Gothenburg Sweden
Abstract
AbstractA computational fluid dynamics (CFD) study of the parameter sensitivity of a wood chips model was performed on an industrial impregnation vessel, which is the first step in a continuous cooking system. The solid and liquid phases were both treated as continua and it was found that the continuum model for the solid wood chips phase could capture the previously observed oscillating formation of arches in the contracting part of the vessel, which will occur at different levels of volume fraction depending on the material constants. The parameters that were examined are the solid pressure, permeability, viscosity, and wall friction. It was found that all the parameters strongly affect the distribution of the wood chips in the vessel as well as the oscillation effects, hence also the flow field which is important to accurately predict in order to ensure optimal performance of the impregnation vessel. Thus, correct material data for these types of simulations are crucial to the outcome and should be chosen for the appropriate situation and bio‐material.