Investigating different methods for numerical simulation of temperature development in a feed section of a single-screw extruder.

For the design of feed sections in single-screw extruders, analytical methods are increasingly being replaced by numerical methods. One possibility for numerical process modeling of solids conveying is offered by the discrete element method (DEM), which is able to calculate individual particle movements and interactions. With DEM it is possible to determine quantities that are difficult to measure and get insight into physical processes. In this paper, dissipation in the solids conveying section is calculated with the help of DEM, since conventional analytical methods until to now are not able to provide precise results due to the complexity of the pellet movement. A specific analysis of the possibilities for dissipation calculations in the solids conveying section is carried out with the software EDEM. Two fundamentally different approaches are compared. On the one hand, the temperature increase is simulated directly via a user-defined contact model, on the other hand, an average temperature increase is calculated indirectly via a macroscopic energy balance. The description of dissipated energy as a result of friction is particularly important as it leads to a direct increase in the temperature in the solids conveying section. For a correct screw design, knowledge of the temperature in this section is essential, as melting of the material inhibits effective solids conveying. Therefore, this paper focuses on the determination of the quantities of the friction work and the resulting temperature. [ABSTRACT FROM AUTHOR]