Modeling of Debris Deposition in an Extrusion Filter Medium

The goal of this work is to predict reasonable lifetime of a filter used to remove debris (e.g. foreign particles and gels) from the melt stream of an extrusion process. We are developing models which incorporate nonNewtonian porous media flow through a medium whose porosity changes as debris accumulates. Boundary conditions are based on the assumption of constant flow rate and coupling with other process stages. Governing equations consist of a mass balance equation for flow of the suspension coupled with a Darcy velocity, the non-Newtonian constitutive equation, and equations for modeling particle transport and deposition. The model is being developed in a manner which allows for generalization to various domains in higher dimensions and more complex constitutive models. One-dimensional Newtonian and non-Newtonian flow models will be presented and compared to one another. Plans for continuing work will also be discussed.