Experimental and numerical investigation into the residence time distribution of granular particles on forward and reverse acting grates

Forward and reverse acting grates are widely employed in waste-to-energy plants. In order to predict the motion of solid granular particles and optimise the design of such systems, Discrete Element Method (DEM) is increasingly used. The objective of this paper is to predict the dynamics of granular particles on forward and reverse acting grates by applying DEM. The residence time distribution of solid particles is analysed by DEM and compared with experimental results in a pilot plant excluding combustion. The results indicate a very good consistency between DEM and experimental results, highlighting the promising capabilities of DEM in predicting the dynamics of granular particles in grate systems. Coupling DEM with computational fluid dynamics techniques can further advance the method to account for thermal conversion of solid fuels in future work.

► DEM is used to study the residence time in forward and reverse acting grates.
► Similar boundary conditions are set in experiments and simulations.
► Only the dynamics of the solid particles is studied and combustion is excluded.
► Very good prediction of the residence time by DEM.
► Better mixing is observed in reverse acting grate compared to forward acting grate.