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This article focuses on the experimental verification of a mathematical derivation of Janssen’s theory, which describes the distribution of pressures within the bulk material and pressure distribution on the walls of storage facilities. The experimental verification is performed in two ways. The first is the real measurement of the load transfer in a bulk material cylinder and the second is similar to the detection of the load transfer through simulations using the DEM method. The aim is to compare the results of the theoretical calculation according to Janssen’s theory with the real measurement and a simulation of exactly the same model situation. At the beginning of any design or optimisation of existing transport or storage facilities, the most important is the analysis of the bulk material in the form of measurements of mechanical-physical properties. The analysis methods used are also described here. The pressure at the bottom of a storage container between the methods used showed negligible differences. From this finding, it can be concluded that the DEM method is a very suitable means for verifying the design of transport and storage facilities. The simulations provide important information and insights that can also be used to optimise existing transport or storage facilities.

• The silo bottom deflection experiments were performed. • The validation of contact parameters using Hertz–Mindlin no slip and Hertz–Mindlin with JKR were designed. • The coupled DEM and FEM simulation was shown as effective tools. • The force reaction occurring at the bin bottom and change of the measuring plate position were observed and evaluated. • The maximum percentage deviation between DEM – real experiment and FEM – real experiment was in good agreement. The trend of modern times is to use the increasingly more advanced technology of design, research and validation of transport, handling, storage and treatment processes using simulation methods. Programs used take advantage of computational algorithms that determine a large variety of different parameters. To extend the applicability of these programs, collaborative plug-ins (systems) are created that allow two or more simulations, analytical programs and methods to work together. In this study the cooperative plug-ins are utilised in an application dealing with the issues caused by Janssen forces/pressures of bulk material and deformation effects acting on the bottom of a bin. An examination of such issues includes observing a change in the position of a measuring plate due to the deformation of a force sensor placed at an outlet of an innovative prototype for measuring deformation effects. The experiment was evaluated and validation of discrete element method (DEM) simulation created; the force effects acting on the bottom of the bin were then transferred to a finite element method (FEM) analysis. This was followed by strength analysis of the force sensor deformation located under the outlet of the bin. A comparison was made between a real experiment and simulations that consisted of filling the bin with bulk material. Force reactions occurring at the bottom of the bin and the change of the position of the measuring plate due to the deformation of the force sensor were observed. The results show a low percentage deviation of the simulation from the real experiment. The maximum percentage deviation of the simulation from the real measurement expressed by the change of the measuring plate position due to the deformation of the force sensor is 3.70% and 0.23% when the forces acting on the measuring plate are compared using DEM. The results confirmed the assumption that the coupled DEM and FEM simulation is suitable for this type of engineering tasks. Application of the above mentioned DEM simulation and FEM analysis appears to be a universal tool for designing, modifying or upgrading of equipment for transporting, treatment and storing bulk material and includes equipment where the active member comes into contact with bulk material. [ABSTRACT FROM AUTHOR]

This paper's goal was to select methods and a calibration procedure which would lead to the determination of relevant parameters of a discrete element method (DEM) and virtual material creation. Seven particulates were selected with respect to their shape (spherical and non-spherical), size and density. The first calibration experiment involved "packing test" to determine the shape accuracy and bulk density of virtual packed particulates. The series of simulations were compared with real experiments, and the size, shape and density of virtual particles were optimized. Using three apparatuses, the input parameter values were experimentally determined for a contact model that defines the behavior of particulates in DEM simulations. The research part of the paper examines the influence of factors such as particle number; pile formation method; and the method of evaluation of the angle of repose on the process of the calibration of virtual material. The most reproducible results were achieved by the "pilling" method and by the rotating drum—both evaluated by the geometric method. However, it is always advisable to make an overall visual comparison of the slope shape between the calibration simulation and the experimental curves. The bowl's diameter to particle size ratio should be greater than 25, and the calibration experiment should contain approximately 4000 particles to ensure representative results during angle of repose calibration experiment. [ABSTRACT FROM AUTHOR]

The process of homogenization of particulates is an indispensable part of many industrial processes, and, therefore, it is necessary to pay a special attention to this area and develop it. This paper deals with a complex study of homogenization of particulate matters in a rotary drum in terms of shape, size, and density of particles. In addition, the influence of operating parameters, such as drum filling capacity, rotational speed, and drum filling pattern are also investigated. Studies of reproducibility of discrete element method simulations, effects of rotary drum sizes or effects of drum volumetric filling to the mixture homogeneity index were also carried out. In general, the least satisfactory values of the homogeneity index resulted from the mixing of particles with different densities. The dominating factor of homogenization was the drum filling-up degree. The course of the homogeneity index in 140, 280, and 420 mm drums was very similar and after five revolutions of the drum, identical values of the homogeneity index were achieved for all the drum diameters. The optimal drum filling-up degree is at 40–50% for the spherical particles and 30–40% for the sharp-edged particles. The repeatability of simulations showed the maximum relative standard deviation of the homogeneity index at 0.6% from ten simulation repetitions with the same parametric conditions. [ABSTRACT FROM AUTHOR]

• The chain conveyor experiments were performed. • 53 alternative designed geometric shapes of chain conveyor carriers were simulated. • A comparison between real experiments and DEM simulations was made. • The DEM simulation was shown as effective tools for shape optimization. • The deviation between DEM and real experiment was small. Traditionally, chain conveyors with classic structural carriers are used to transport bulk materials. The research topic of the study was how various geometric carrier shapes could affect, for example, transportation efficiency, wear or the action of forces. For this purpose, 53 alternative geometric shapes were designed and simulated in DEM. The efficiency of the geometric shapes was calculated in terms of the material transport speed, the acting compressive forces, the particulate velocities around the carriers, the wear of the carrier surface, and the resistances in carrier movement. The input parameters of the DEM model of the bulk material and conveyor were experimentally verified by the angle of repose and the validation device of the chain conveyor. Deviations of the DEM validation of material and processes in the conveyor fell in the range 0.29–3.17%. The effect of compressive forces acting on carrier I, II and V was also investigated to determine the efficiency of the processes. Because of the large number of simulations, we designed an optimal simplified model, which was validated with a 2% difference from the original and more computationally demanding model. Based on all the (measured and simulated) values, we determined the optimal design of the carriers by examining the overall efficiency. We found four alternative carrier shapes for the effective area. The article provides a comprehensive overview of the modern methods of analysis and subsequent optimization of contact geometrical surfaces for the purpose of creating prototypes with low economic requirements. [ABSTRACT FROM AUTHOR]