Meshless Modeling of the Breakage Process of a Coal Prism within Vertical Roller Mills

This paper presents an investigation into the roll compression induced breakage process of a coal prism within a vertical roller mill. The targeted process was characterized by strong nonlinearities arisen from large deformation, and from original continuum to final discontinuum. A numerical approach coupling the Smoothed Particle Hydrodynamics (SPH) method and the finite element method (FEM) was developed for such a type of analysis. The SPH method was used to model a coal prism and its interaction with the mill structure, while the roller and the support table in the mill were modeled with the FEM. This computational model makes it possible to predict the deformation and progressive disintegration process in the coal prism, as well as the reaction force mobilized along the specimen-roller interface. Using a cubic coal specimen as an instance, the paper presents a preliminary numerical study under prescribed geometry and working conditions of a mill machine. Typical results of the breakage process as well as the development of contact force were provided and discussed.