Energy Optimisation of a Single Toggle Jaw Crusher using Discrete Element Method

Mwangi P, Muvengei O, MBUYA TO, Ndeto M. "Energy Optimisation of a Single Toggle Jaw Crusher using Discrete Element Method." Journal of Sustainable Research in Engineering. 2020;5(4):180-193.


Comminution process has always been associated with very low energy efficiencies. Most of the energy during
comminution is lost through noise, heat and vibrations. Therefore, it is necessary to obtain the optimal operating parameters of a comminution machine. In this research, the efficiency of a jaw crusher has been optimised using Genetic Algorithms (GA) and Discrete Element Method (DEM) techniques. DEM, even though a powerful tool, demands high computational capabilities hence a scaled down jaw crusher was used for simulation purposes. The GA codes were used in determining the critical velocity and also in developing the equation for up-scaling the jaw crusher. Critical parameters which affect the power consumption of a jaw crusher are toggle speed, throw and reduction ratio. These parameters were varied during the simulation as guided by the design of experiment technique. In addition, a Bonded Particle Model (BPM), was used in modelling the rock used in the simulation. A BPM model gives more realistic results than Particle Replacement Model (PRM) and Fast Breakage Model (FBM). To create the BPM of an irregularly shaped rock, custom API factory was coded in C++ and loaded to EDEM software. At the end of this research, the optimal energy efficiency was obtained as 59.7758% at a toggle speed of 157.7965 rpm, a throw of 33.445 mm and a reduction ratio of 4. A mathematical model showing the relationship between energy efficiency and process parameters was also developed.

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