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Tytuł:
Feeder type optimisation for the plain flow discharge process of an underground hopper by discrete element modelling
Autorzy:
Necas, J.
Hlosta, J.
Zurovec, D.
Zidek, M.
Rozbroj, J.
Zegzulka, J.
Powiązania:
https://bibliotekanauki.pl/articles/101876.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
drag chain conveyor
discrete element method
simulation
Opis:
This paper describes optimisation of a conveyor from an underground hopper intended for a coal transfer station. The original solution was designed with a chain conveyor encountered operational problems that have limited its continuous operation. The Discrete Element Modeling (DEM) was chosen to optimise the transport. DEM simulations allow device design modifications directly in the 3D CAD model, and then the simulation makes it possible to evaluate whether the adjustment was successful. By simulating the initial state of coal extraction using a chain conveyor, trouble spots were identified that caused operational failures. The main problem has been the increased resistance during removal of material from the underground hopper. Revealed resistances against material movement were not considered in the original design at all. In the next step, structural modifications of problematic nodes were made. For example, the following changes have been made: reduction of storage space or installation of passive elements into the interior of the underground hopper. These modifications made were not effective enough, so the type of the conveyor was changed from a drag chain conveyor to a belt conveyor. The simulation of the material extraction using a belt conveyor showed a significant reduction in resistance parameters while maintaining the required transport performance.
Źródło:
Advances in Science and Technology. Research Journal; 2017, 11, 3; 246-252
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Aspect Ratio on Iron-Ore Briquettes During Twin-Roll Briquetting
Autorzy:
Kim, Kang-Min
Bae, Jong-Ho
Han, Jeong-Whan
Powiązania:
https://bibliotekanauki.pl/articles/355616.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
numerical analysis
discrete element method
roll briquetting
Opis:
In the ironmaking, sizes of raw materials such as iron ores and coke must be adjusted for subsequent process in the blast furnace. The depletion of high grade iron ore in recent years necessitates a technology that can utilize low-grade fine iron ores. Thus, steelmakers have been studying the sinter-briquette complex firing process that employs a method of charging the sinter feed together with briquettes made of fine iron ore. In this process, larger briquettes increase the briquette productivity per unit time but decrease the green strength of briquettes and they can break during transportation and charging. Thus, the briquette shape is very important. Therefore, in this study, we simulate a twin roll briquetting process using the DEM analysis and compared the compressive force distributions in the briquette for different aspect ratios. This study is a new attempt, because research cases by numerical methods on the same or similar systems are very rare. Consequently, the optimal aspect ratio is 0.5 at briquette height 20 mm, 2.0 at 30 mm, and 1.5 at 40 mm. Also, the average compressive force increased in proportion with the pocket height at the sameaspect ratio. Therefore, to increase the pocket depth for high productivity, the pocket height must also be increased for obtaining high strength briquettes.
Źródło:
Archives of Metallurgy and Materials; 2020, 65, 4; 1335-1339
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Deflector Plate for Particle Size Segregation Control
Autorzy:
Kim, Kang-Min
Kim, Ju-Hun
Kwon, Jae-Hong
Lee, Ji-A
Han, Jeong-Whan
Powiązania:
https://bibliotekanauki.pl/articles/353855.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
size segregation
numerical analysis
discrete element method
Opis:
In general, uniform mixing of particles is desirable in the process of particle handling. However, during the charging of sinter feed and upper ore, size segregation must be induced to prevent heat imbalance, ensure bed permeability, and prevent the loss of fine ore. In this study, upper ore charging was simulated using a discrete element method (DEM) to find the optimal method for controlling particle size segregation, and the segregation characteristics in the upper ore bed were investigated when a deflector plate was applied to the charging machine. The degree of vertical segregation increased when a deflector plate was applied, and it was confirmed that the segregation direction in the upper ore bed can be controlled by adjusting the charging direction of the upper ore by using a deflector plate. In order to apply this method directly to the actual process, further study is needed to understand the influence of the characteristics of the deflector plate such as length and angle.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 2; 495-500
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of mechanical properties for wood pellets used in DEM simulations
Autorzy:
Gallego, E.
Fuentes, J.M.
Ruiz, A.
Hernandez-Rodrigo, G.
Aguado, P.
Ayuga, F.
Powiązania:
https://bibliotekanauki.pl/articles/2082921.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
biomass
wood pellets
mechanical properties
discrete element method
Opis:
Wood pellets are increasingly being used to produce energy as a part of the decarbonization process of the economy, but their handling is associated with several problems, which usually requires that the equipment used has to be modified and improved. The discrete element method is a numerical technique suitable for simulating individual particles and handling systems. This paper focuses on the determination of the mechanical and physical parameters for wood pellet particles which are required to develop a discrete element method model to improve handling and transport systems. This study reports the experimentally determined values for wood pellet particles with respect to particle density, modulus of elasticity, particle – particle and particle – wall coefficients of restitution, and particle – particle and particle – wall coefficients of friction. Following the previous findings by other researchers with large samples of bulk material, it has been found that the modulus of elasticity for individual wood pellets depends on the water content, and the particle – wall coefficient of restitution depends on the impact velocity.
Źródło:
International Agrophysics; 2020, 34, 4; 485-494
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical simulations of the exploitation parameters of the rotary feeder
Autorzy:
Karwat, Bolesław
Rubacha, Piotr
Stańczyk, Emil
Powiązania:
https://bibliotekanauki.pl/articles/27315596.pdf
Data publikacji:
2022
Wydawca:
STE GROUP
Tematy:
bulk materials
Discrete Element Method
exploitation characteristics rotary feeder
Opis:
The article presents the problems of determining the mass efficiency of a rotary feeder depending on the selection of design parameters of the device, such as outer diameter, number of blades and rotational speed of the rotor. The hitherto theoretical methods of calculating the feeder efficiency were presented, as well as a new method of determining the device operation parameters was proposed. For this purpose, the numerical Discrete Element Method was used, which allowed simulating the transport of limestone powder in a cell feeder with various design variants. The results of the tests showed that the above design parameters affect the instantaneous efficiency of the feeder and thus impact the distribution of the dosed material during the operation of the device. Depending on the design solution, the simulation results gave information on the fill factor of the feeders. The study showed a significant potential of DEM simulation in the design of circular feeders intended for dosing bulk materials.
Źródło:
Management Systems in Production Engineering; 2022, 4 (30); Bibliogr. 33 poz., rys., tab.
2299-0461
Pojawia się w:
Management Systems in Production Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new approach for obtaining the geometric properties of a granular porous bed based on DEM simulations
Autorzy:
Sobieski, W.
Dudda, W.
Lipiński, S.
Powiązania:
https://bibliotekanauki.pl/articles/297977.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
granular beds
spatial structure
Discrete Element Method
PathFinder code
Opis:
In the article, a new way for obtaining a set of geometrical parameters of granular porous beds is presented, if the data on the locations and sizes of all particles is available. The input data were prepared with the use of Discrete Element Method. The other way for acquiring the input data may be the application of Computed Tomography (CT) and Image Analysis (IA) techniques. All geometrical parameters are calculated with the use of own numerical code called PathFinder (freely available in the Internet together with its source code). In addition to description of the method of calculations, two examples of its use are presented. One simulation was performed in PFC3D code, and the other in YADE software. The aim of the article was to show clearly that a porosity is not sufficient to describe the spatial structure of a porous body. In both presented examples, the porosity value is almost the same, but other parameters, e.g. tortuosity, are different. The motivation to write the PathFinder code were significant problems with obtaining geometrical parameters needed in investigations related to granular porous media. The issues described in the article are a part of an overall research methodology relating to the linking the micro- and macro-scale investigations of granular porous beds. The areas of applications of this methodology are not discussed in the article.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2016, 19(2); 165-187
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of a screw conveyors exploitation parameters
Autorzy:
Karwat, Bolesław
Rubacha, Piotr
Stańczyk, Emil
Powiązania:
https://bibliotekanauki.pl/articles/1841744.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
screw conveyor
discrete element method
bulk material
exploitation characteristics
Opis:
The paper describes the problem of designing screw conveyors in terms of determining their exploitation characteristics. Based on the actual values of mass efficiency and power demand obtained in a laboratory experiment, the theoretical design methods and the numerical discrete element method model results were verified. The obtained results have shown that the currently used theoretical methods underestimate the mass efficiency and power demand compared to experiments when typical values of filling rate coefficient and progress resistance coefficient are used. It was also shown that the results of DEM simulations are in good agreement with the experiments in terms of mass efficiency and power demand. Based on the exploitation characteristics determined in DEM simulations for different constructions of the screw and different rotational speeds, multi-objective optimization of the exploitation parameters of the screw was performed in order to minimize the power demand of a screw conveyor and simultaneously maximize its mass efficiency. The optimization results showed that it is possible to find such construction and the rotational speed that will maximize the mass efficiency of the conveyor and keep the power demand low, reducing the exploitation costs of the device.
Źródło:
Eksploatacja i Niezawodność; 2021, 23, 2; 285-293
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The vertical screw conveying characteristics of cohesive particle and optimization of design parameters
Autorzy:
Chen, Suifan
Zhang, Xiaomeng
Li, Qipeng
Shen, Ce
Shi, Yongchang
Powiązania:
https://bibliotekanauki.pl/articles/24200814.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
discrete element method
conveying characteristics
NSGA-II
comprehensive evaluation
Opis:
The purpose of this paper is to solve the problem of low conveying efficiency and serious blade wear during vertical screw conveying of cohesive particles. Firstly, the reliability of DEM simulation was verified by comparing the simulated and theoretical values and the influence regularity of different design parameters (rotational speed, pitch, and clearance) on screw conveying characteristics were analyzed based on DEM. In addition, the effect of design parameters on the screw conveying characteristics is identified by ANOVA. Then, the multi-objective optimization model with the both of maximizing the average mass flow rate and minimizing the maximum wear depth of the blade was established using the polynomial fitting regression, which was solved by the non-dominated sorting genetic algorithm (NSGA-II). Finally, the comprehensive evaluation was used to determine the best design parameters. The above research results provide a certain reference for the study of cohesive particle’s vertical screw conveying characteristics and equipment optimization design.
Źródło:
Eksploatacja i Niezawodność; 2023, 25, 1; art. no. 13
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of conveyor belt wear caused by material acceleration in transfer stations
Autorzy:
Doroszuk, Błażej
Król, R.
Powiązania:
https://bibliotekanauki.pl/articles/89064.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Wydział Geoinżynierii, Górnictwa i Geologii. Instytut Górnictwa
Tematy:
conveyor transfer station
discrete element method
acceleration length
abrasive wear
Opis:
In conveyor transport systems, different solutions to the transfer points constructions are used. Choosing the right solution requires conditions analysis of the cooperation between two conveyors. For years, the analytical methods have been used to evaluate the discharge trajectory of the transported material. Increasingly, to evaluate the movement of grains in the transfer space to analyze the behavior of the bulk material in contact with transfer chute elements, researchers successfully use simulations performed in the discrete element method (DEM). Well-constructed chute allows the material stream to be uniformly fed onto the receiving conveyor with a desired stable tangential speed. Proper design reduces motion resistances and belt wear. In the paper, the analysis of selected construction solutions of transfer points and the possibilities of their usage in copper ore transport systems were performed. The research was conducted using the DEM simulations of the ore flow. For specifying the best conditions of the cooperation of the feeding and receiving conveyors, a series of simulations were generated. The criteria for the comparative evaluation of the analyzed solutions were the values of acceleration zone length and abrasive wear of the belt.
Źródło:
Mining Science; 2019, 26; 189-201
2300-9586
2353-5423
Pojawia się w:
Mining Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
3D DEM simulations of basic geotechnical tests with early detection of shear localization
Autorzy:
Grabowski, Aleksander
Nitka, Michał
Powiązania:
https://bibliotekanauki.pl/articles/1845158.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
direct shear
granular material
discrete element method
localization
grain level
Opis:
This paper deals with elementary geotechnical tests: triaxial and direct shear of cohesionless sand using the discrete element method (DEM). The capabilities of the numerical DEM code are shown, with a special focus on the early phenomena appearance in localization zones. The numerical tests were performed in 3D conditions with spherical grains. Contact moments law was introduced due to simulate not perfectly round sand grains. The influence of different physical parameters was studied, e.g. initial density or confining pressure. The sieve curve corresponded to the Karlsruhe sand [1]; however, in some tests, it was linearly scaled. Special attention was laid on the behaviour of the sand grains inside localization, e.g. rotation, porosity, fluctuations, etc. and forces redistribution. Emphasis was given on the pre-failure regime and early localization predictors.
Źródło:
Studia Geotechnica et Mechanica; 2021, 43, 1; 48-64
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
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