Modelling of a Viscoelastic Compression Model for the Simulation of Mechanical Dewatering Processes, 19PaperCon
During the papermaking process, a pulp web is continuously dewatered and dried. Mechanical dewatering in the press section significantly defines the properties and the quality of the paper. Furthermore an improved mechanical drainage significantly reduces thermal energy consumption in the following dryer section. This increases the efficiency of the entire papermaking process. However, the physical processes inside the press nip are still poorly understood and can be only measured with huge efforts. Modeling and simulation of the mechanical dewatering offers insights into the process which are hardly achievable by measurements and experiments. Thus the simulation can be used to improve and redesign the process and the components involved.
The 1-D modeling approach for mechanical dewatering is based on effective parameters to ensure fast and efficient calculations. By a modular concept, heterogeneous layers with individual flow and material transport equations can be combined to larger units, such as felt and paper layers, which are provided by our in-house developed simulation library. The most important physical models included in each layer are a two-phase flow model interacting with a structural-mechanical compression model. The later one will be the focus topic of this presentation.
Laboratory tests have shown that the dewatering behavior of paper and felt significantly depends on the compression behavior of the paper web. For our simulation approach, we use a macroscopic compression model which follows a spring-damper approach. Due to high strain rates and the high proportion of irreversible deformation it contains nonlinearities and modifications to conventional viscoelastic models for solid materials. For development and calibration of the compression model, data sets from laboratory tests with fully saturated paper webs were used. Optimization algorithms were applied to obtain the effective parameters of the compression models by fitting the models to the measured data.
TAPPI conference proceedings and presentations, technical papers, and publication articles provide technical and management data and solutions on topics covering the Pulp, Paper, Tissue, Corrugated Packaging, Flexible Packaging, Nanotechnology and Converting Industries.
Simply select the quantity, add to your cart and your conference paper, presentation or article will be available for immediate download.
Modelling of a Viscoelastic Compression Model for the Simulation of Mechanical Dewatering Processes,