Review of Discrete Element Modelling in Optimisation of Energy Consumption of a Single-Toggle Jaw Crusher

Abstract

This review paper has focused on optimisation of energy consumption during comminution process within the crushing chambers of a single toggle jaw crusher. Comminution has always been associated with operational efficiencies of below 10% due to energy dissipation during size-reduction through noise, heat and vibrations. Optimisation techniques such as altering the feed material characteristics through heat treatment have been proposed. However, such techniques increase the overall cost of aggregate production. Therefore, the most appropriate technique is optimising the jaw crusher dimensions such as the reduction ratio, throw and toggle speed using Genetic Algorithms (GA) and Discrete Element Modelling (DEM). The Rose and English model has been proposed for optimisation and is used together with GA. Even though the GA will reveal the optimal design parameters, it does not account for stresses,  deflections and physical properties of the material and jaw crusher. This gives a strong incentive to use Discrete Element Method (DEM) in performance optimisation of the jaw crusher. DEM modelling has the capability of predicting the machine’s power draw and process parameters. DEM models that have been proposed included Bonded
Particle Model (BPM), Particle Replacement Model (PRM) and Fast Breakage Model (FBM). Of the three, BPM was found to be superior in compression induced fractures. PRM is suitable for impact crushing while FBM is ideal for flow-induced breakage.