Estudio de la segregación de una mezcla granular en una máquina compresora mediante el método de los elementos discretos(DEM)

Abstract

Main goal of this work is to present the application of discrete element method (DEM) to study the segregation phenomena that occur in the feed hopper of a tablet compression machine (‘single punch’ eccentric press). The discrete element method, which is classified in the family of numerical methods, allows simulating parameterized models of granular systems and discontinuous materials. Specifically, the software used to carry out these analyses is EDEM®, in which it is possible to either implement the geometry of the elements to simulate or import it from a CAD tool. Thus, the aim of this study is to obtain deeper knowledge about the segregation of certain ingredients of a mixture (usually with larger size or density) that occurs within a feed hopper of an eccentric compression machine. For this purpose, the model parameters (mainly the coefficients of friction) are adjusted by comparison with compression tests performed with polycarbonate prototype. Once the model is adjusted, it is possible to simulate the segregation process. This allow us to modify the geometry of the hopper in order to mitigate these phenomena as far as possible, without carrying out extensive and expensive real laboratory tests.