Simulation of Reacting Moving Granular Material in Furnaces and Boilers An Overview on the Capabilities Of the Discrete Element Method

Scherer, Viktor; Wirtz, S.; Krause, Bastian; Wissing, F.

doi:10.1016/j.egypro.2017.07.154

Cited by 12 publications

(5 citation statements)

References 49 publications

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“…The geometrical dimensions of 100 pellets are randomly measured by the Vernier Calipers; they can get a pellet with an average length L of 7.98 mm and an average radius R of 2.5 mm. At the same time, if the density measurement of a pellet is 1538 kg•m −3 , then the discrete element modeling of a pellet is established according to the above data [16,[35][36][37][38][39][40][41]. In order to truly restore the state of the pellets and consider the computation of the simulation test, it is usually necessary to adjust the number and size of subspheres.…”

Section: Simulation Conditionmentioning

confidence: 99%

Study the Flow Capacity of Cylindrical Pellets in Hopper with Unloading Paddle Using DEM

Huang,

Zhang,

Wang

et al. 2024

Agriculture

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The hopper is an important piece of basic equipment used for storing and transporting materials in the agricultural, grain, chemical engineering, coal mine and pharmaceutical industries. The discharging performance of hoppers is mainly affected by material properties and hopper structure. In this work, the flow capacity of cylindrical pellets in the hopper with the unloading paddle is studied. A series of numerical simulation analyses with the aid of the discrete element method (DEM) platform are carried out. Then, the discharging process is illustrated, and the flow capacity of pellets in the hopper is analyzed by the mass flow index (MFI), the dynamic discharging angle (DDA) formed in the discharging process and porosity among pellets. Furthermore, the effect of parameters such as hopper half angle, rotation speed of the unloading paddle and outlet diameter of the hopper is investigated. The results show that MFI increases with an increase in hopper half angle or outlet diameter and a decrease in rotation speed. Meanwhile, DDA and porosity decrease with the increase in the hopper half angle or outlet diameter and the decrease in the rotation speed. Finally, the MFI ~0.24 is identified as the criterion to distinguish the mass flow from the funnel flow for the hopper with an unloading paddle, and the optimization results are decided as follows: hopper half angle greater than 60°, outlet diameter greater than 60 mm and rotation speed between 45 rpm and 60 rpm. These results should be useful for providing a theoretical reference for the optimization design of feeding devices for swine feeders.

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Section: Simulation Conditionmentioning

confidence: 99%

Study the Flow Capacity of Cylindrical Pellets in Hopper with Unloading Paddle Using DEM

Huang,

Zhang,

Wang

et al. 2024

Agriculture

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“…Moreover, despite the relatively low number of cells (120,000 computing cells for CFD simulation in [23]), the CFD-DEM coupling method is complex and, above all, highly time-consuming, which make its use for industrial scale simulations problematic. DEM simulations are more computationally expensive than CFD [60], especially for the large amount of stones involved in this case. In addition to the two different types of simulations, it is necessary to implement a communication system to translate data between them.…”

Section: Limestone Calcination Modelmentioning

confidence: 99%

CFD Analysis of Co-firing of Coke and Biomass in a Parallel Flow Regenerative Lime Kiln

Arévalo

Rezeau

Herce

2022

Waste Biomass Valor

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The lime industry is a highly energy intensive industry, with a huge presence worldwide. To reduce both production costs and pollutants emissions, some lime production plants are introducing more environmentally-friendly energy sources, such as local agro-industry residues. In this paper, a numerical tool is presented, which simulates a large-scale Parallel Flow Regenerative (PFR) kiln that currently uses coke as main fuel. The developed tool aims at investigating the combustion process under conditions of co-firing of coke and biomass and to assist the plant operators in the optimization of such operating conditions. To achieve this goal, a two-way coupling Euler–Lagrange approach is used to model the dynamics of the particulate phase and their interaction with the gas phase. Pyrolysis, volatiles oxidation and char oxidation are modelled by kinetics/diffusion-limited model (for heterogeneous reactions) and mixture fraction approach (for homogeneous reactions). Moreover, two methods are investigated for representing the limestone bed: a porous medium (PM) approach and a “solid blocks” (BM) tridimensional mesh. Comparison of the results for the case of 100% coke showed that the ideal “blocks” method is more accurate as it adequately simulates the scattering of fuel particles through the PFR kiln anchor, which is limited with the PM approach. Moreover, the temperature profile, maximum and minimum temperatures, as well as CO2 and O2 concentrations at outlet, are comprised in the expected range for this technology, according to available literature. Finally, the predicted results of a co-firing case with 60% biomass (in mass) were validated with measurements in an industrial facility, with production capacity of 440 calcium oxide tons per day. The results suggest that the model is fairly accurate to predict gas temperature, as well as O2 and NOX concentrations at the kiln outlet. Although some improvements are recommended to refine the CFD predictions, these promising results and the high computational efficiency laid the foundation for future modelling of co-firing of coke and biomass, as well as the modelling of the lime calcination process. It also paves the way for facilitating the reduction of pollutant emissions thus contributing to a more sustainable lime production. Graphical Abstract

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“…These last two reviews, however, are mainly limited to small particles (mm‐range, thermally thin), with the typical application being fluidized beds. An early overview on the DEM/CFD simulation of thermally thick particles is given by Scherer et al in 2017 13.…”

Section: Introductionmentioning

confidence: 99%

Simulation of Reacting, Moving Granular Assemblies of Thermally Thick Particles by Discrete Element Method/Computational Fluid Dynamics

et al. 2023

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The potential and limitations of the discrete element method (DEM) coupled with computational fluid mechanics (CFD) to simulate chemically reacting, moving granular material interacting with a fluid flow are summarized. A special focus is set on thermally thick particles, which requires to resolve the intraparticle transport and reaction processes. The aspect of complex particle shape is addressed, as shape may dominate the particle behavior in densely packed granular assemblies even more than the details of contact force laws. The fluid flow in the granular assembly is assumed to be a gas. The potential of DEM/CFD will be highlighted presenting three illustrative examples: a large-scale lime shaft kiln with intermittent operation, an industrial-size grate firing system for the incineration of municipal waste, and a small-scale straw pellet stove.

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Simulation of Reacting Moving Granular Material in Furnaces and Boilers An Overview on the Capabilities Of the Discrete Element Method

Cited by 12 publications

References 49 publications

Study the Flow Capacity of Cylindrical Pellets in Hopper with Unloading Paddle Using DEM

Study the Flow Capacity of Cylindrical Pellets in Hopper with Unloading Paddle Using DEM

CFD Analysis of Co-firing of Coke and Biomass in a Parallel Flow Regenerative Lime Kiln

Simulation of Reacting, Moving Granular Assemblies of Thermally Thick Particles by Discrete Element Method/Computational Fluid Dynamics

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