Granular Flow Simulation for the Design and Operation of De-manufacturing Processes and Systems

Products and material mixtures found in E-waste are highly inhomogeneous and in continuous evolutions. In spite of this variability, state-of-the-art mechanical recycling systems are extremely rigid, both in their design and parameter settings. This is mainly due to the lack of knowledge-based engineering models and tools to support the design and operation of separation processes able to capture, with an acceptable level of confidence, all the major phenomena affecting the quality of the output, including particle-particle interactions and impacts. In this paper, multi-body granular flow simulation is proposed as a modeling and analysis tool able to capture the physics of mechanical separation processes and to support process parameter design, operation and control in industrial settings. The simulation of granular flows in waste material is complicated by the non-smooth and discontinuous nature of the contact phenomena between the particles, and between the particles and parts of the processing equipment. The approach adopted in this paper, based on the recent theory of Differential Variational Inequalities (DVI), is an alternative to the classical Discrete Element Method (DEM), and it is suitable to handle up to millions of contacts between particles, without decreasing integration time steps. The proposed models are validated by experimental analysis carried out at the “De-manufacturing Pilot Plant” at ITIA-CNR. Results show that this modeling framework can be used in practical settings to predict the separation performance as a function of the process parameters.