Validation of movement over a belt conveyor drum

This paper presents the use of new modern methods for the research of movement of material on a belt conveyor. One of the innovative methods is Particle Image Velocimetry (PIV), which was used to scan and assess the two-dimensional vector field of speed of particles on the belt conveyor. Outputs from PIV were compared to simulations of the same transport process. These simulations were performed using the Discrete Element Method (DEM). Four transport speeds of material were assessed for a real and simulative belt conveyor model. Software tracking of particle movement was used to determine and compare the trajectories of paths of particles leaving the belt conveyor drum. Validation of the DEM simulation of material movement over a belt conveyor drum using PIV provided acceptable results in the area of particle speed fields. Comparison of the particle path trajectory corresponds to the preliminary hypothesis which leads to calibration of the DEM simulation. The results and assessment of this paper were created based on validation.Web of Science11212411

Simulation of material flow through a sample divider

The prerequisite for a modem approach to innovative procedures of the development of current or even newly created equipment for the transport of particulate materials is the utilization of simulation methods, such as the Discrete Element Method (DEM). This article focuses on the basic, or initial, validation of movement of material through the sample divider. The mechanical-physical properties of brown coal were measured. Based on these parameters the preliminary input values for EDEM Academic were selected, and a simulation of the dividing process was run. The key monitored parameters included density and friction coefficient. Experiments on a realistic model of the equipment were performed and assessed. The total weights of brown coal at the exit from the divider were determined for a specific speed of the divider. The aim of this task was to simulate the realistically determined weight division of the brown coal sample. The result from the DEM was compared with the results of measurement on a realistic model.Web of Science12119919

Measurement of amount for steel abrasive material transported by special scraper conveyor

Results obtained from measuring the required amount of steel abrasive material with various fragmentations, which is transported by a special kind of scraper conveyor, offers information that is useful for operators of the abrasive blast cabinets. The presented article describes an innovative methodology developed for determination of the most relevant operational parameters relating to the above-mentioned situation. The most important parameters in this case are: the optimal amount of the abrasive material, the conveying speed of the scraper conveyor and the feeding of the conveyor with regard to partial or full elimination of instable operational area. Elimination of the instable operational area is possible by means of a simple constructional modification of the given conveying system according to the results obtained from experimental investigation, which was performed using special, originally developed laboratory testing equipment.Web of Science114art. no. 185

Návrh rekonstrukce zásobníku slinku

Práce dodaná autorem není finální verzí dokumentu, proto není veřejně dostupnáBakalářská práce se zabývá metodikou řešení rekonstrukce zásobníku na sypké hmoty a to pro slinek (cement). V úvodu je popsáno rozdělení zásobníku, základní pojmy , vzorce pro technologický výpočet a měření. Na základě těchto informací je založeno řešení, je proveden technologický výpočet, vyroben zmenšený model zásobníku a změřen vzorek. Následně podle těchto naměřených a vypočítaných údajů jsou vytvořeny výkresy. Protokoly měření a výkresy jsou ve formě přílohy a jsou řešením této bakalářské práce.Prezenční342 - Institut dopravyNeuveden

The Verification and Validation of DEM Models of the Bulk Materials in the application for the bucket elevators and the possible solutions in practice

Import 18/04/2016Disertační práce se zabývá problematikou inovativního návrhu a optimalizace korečkových elevátorů a dopravních procesů na tomto zařízení. V úvodní části disertační práce je uveden zjednodušený popis korečkových elevátorů a problematika plnění a vyprazdňovaní těchto zařízení se základními výpočetními vztahy. Dále je popsán současný způsob návrhu těchto zařízení s podporou 3D programů a nový, vylepšený způsob návrhu a optimalizace pomocí metody DEM. Vlastní část disertační práce se zabývá optimalizací plnění a vyprazdňování korečkových elevátorů s využitím metody diskrétních prvků. Nejdříve jsou provedena měření mechanicko-fyzikálních vlastností zvolených materiálů, která slouží jako vstupní hodnoty do simulační metody. Dále je navrženo prostředí, ve kterém simulace probíhá, což je tvorba 3D modelu korečkového elevátoru, u kterého jsou dále naprogramovány příslušné pohyby, rychlosti a geometrie, z kterých se generuje vstupující dopravovaný materiál. Použitelnost a přesnost vypočítaných simulačních výsledků je třeba ověřit s reálnými výsledky. Disertační práce proto pokračuje validací dynamického toku partikulární hmoty na nově navrženém patentovaném validačním korečkovém elevátoru. Po ověření pravdivosti simulačních výstupů v hlavě zařízení jsou vypočteny simulace i v patě korečkového elevátoru. Všechny tyto výsledky jsou dále využity k optimalizaci validačního stroje. Práce pokračuje použitím nové metody návrhu k optimalizaci korečkového elevátoru, který bude v průmyslu využíván pro dopravu abraziva. Na tomto zařízení je provedena simulační optimalizace vstupu a výstupu materiálu. V závislosti na vypočtených výsledcích jsou navrženy základní konstrukční úpravy pro zvýšení účinnosti tohoto zařízení. V závěru disertační práce jsou zhodnoceny optimalizační výsledky a možnosti, jak dále vylepšit a zpřesnit tuto inovativní metodu návrhu.The thesis deals with the innovative design and optimization of bucket elevators and their transport processes. The first part of the thesis is focused on a basic description of bucket elevators and the issue of filling and emptying of these devices with basic computing formulas. This part of the thesis also describes the current method of the design of these devices with 3D programs and an improved method of the design and optimization using the DEM method. The main part of the thesis deals with the optimization of filling and emptying of the bucket elevators using the method of discrete elements. The first step involves the measuring of the mechanical and physical properties of the selected materials which are used as input of the simulation method. Then a 3D model of the bucket elevator as an environment for the simulation is designed and the relevant movements, speed and geometry are programmed from which the incoming transported material is generated. The application and accuracy of the calculated simulation results are necessary to verify with real results. Therefore, the thesis continues with the validation of the dynamic flow of the particulate material on the innovated and patented validation bucket elevator. After the verification of the simulation output in the head of the device, the simulations are also calculated in the base of the bucket elevator. All these results are used for the optimization of the validation machines. The thesis continues to describe the new method to optimize the bucket elevator, which will be used for the transport of abrasives in industry. The optimization of the input and output is provided for this device. Based on these results the modifications for the design are proposed to increase the efficiency of this device. In the conclusion of this thesis optimization results are evaluated and the improvements for this innovative method are described.Prezenční342 - Institut dopravyvyhově

Project of depiler for semi-finished steel products - slabs

Import 01/11/2007Prezenční342 - Institut doprav

Hard gelatine capsules: DEM supported experimental study of particle arrangement effect on properties and vibrational transport behaviour

Hard gelatine capsules remain a relevant dosage form for today's pharmaceutical manufacturing. A wide range of colour and print options supports marketing, brand image and patient loyalty. However, the filling of these cap-sules with various modern dosage forms and combinations thereof may affect their further processing. Therefore, a detailed study was carried out to assess the effect of mechanical-physical properties on the behaviour of differ-ently filled hard gelatine capsules. Capsules filled with powder, free or fixed particles presenting drug microforms and also hard gelatine capsules themselves were evaluated. Basic mechanical-physical characterisation was per -formed on all samples. Furthermore, their transport on the vibrating conveyor was assessed and simulated using DEM. The results showed a significant influence mainly by the degree of capsule imbalance, i.e., the arrangement of particles in the capsule. It was found that the hard gelatine capsules showed an average of 15.6 degrees lower values for the effective angle of internal friction compared to the powdered vitamin mixture, and in parallel, an average of 14.7 degrees lower values for the static angle of repose were also recorded. The results of the experiments on the vi-brating conveyor at a frequency setting of 15 Hz showed three times longer transport time for the vitamin mix-ture compared to the capsules. Increasing the frequency evened out these differences.Web of Science405art. no. 11752

Wood pellets transport with vibrating conveyor: Experimental for DEM simulations analysis

This work presents a comprehensive overview of the mechanical-physical parameters of the transport material affecting the vibratory transport. For this purpose, spruce pellets of different lengths, oak rods and spruce crush were tested. The determined parameters were particle size distribution and shape, internal friction, static and dynamic angle of repose. The samples were transported by a patented validation vibrating conveyor. Various settings were used. The results show that by changing the shape, it is possible to reduce friction or resistance as well as energy intensity during transport. It was observed that perfect shapes and lighter particles have lower friction, but a more pronounced bounce. Therefore, it does not form a typical pattern during transport, as in the case of an imperfectly shaped one. There is also included a simulation of the discrete element method. The study shows the possibility of the vibration machine where the material can be conveyed either directionally or sorted.Web of Science111art. no. 1660

The pelletization and torrefaction of coffee grounds, garden chaff and rapeseed straw

Waste biomass pelletization is a suitable process for obtaining energy dense solid fuel. If the pellets are further processed by torrefaction, both their qualitative and energy parameters are changed. Therefore, the objective of this study is to investigate the effect of the torrefaction process on pellets made from coffee grounds, garden chaff and rapeseed straw. Mechanical parameters, such as the pellet durability index, the wettability index of the pellets, their water moisture resistance, hardness, or specific and bulk density were determined for evaluation. Furthermore, pellet energy parameters such as the heat of combustion, calorific value, or elemental analysis were compared. Pelletization of the above-mentioned waste biomass and the torrefaction of the pellets were carried out in pilot plants. The first results showed that the torrefaction process for all samples increased the values of the heat of combustion or the values of the carbon content. The energy value of the pellets increases. The higher heating value of torrefied coffee ground pellets reached 26 MJ kg−1. The ash content also increases with these values. A simple energy balance has been carried out. Therefore, the study shows an insight into the energy use of coffee grounds and chaff from the garden compared to the results of the rapeseed straw pellets for the pelletization and torrefication process.Web of Science21035434

Characterization and flowability methods for metal powders

With the rise of additive technologies, the characterization of metal powders is increasingly required. There is a need to precisely match the properties of metal powders to a specific machine and to ensure highly consistent production. Therefore, the study aims at a detailed characterization of ten metal powders (Metal powder 316 L, Zn, Sn, Al, Cu, Mn, Fe, Bronze, Ti and Mo powder), for which the particle size distribution, morphology, static and dynamic angle of repose and the effective internal friction angle (AIFE) were determined. The AIFE parameter and flow index were determined from three commonly used rotary shear devices: The computer-controlled Ring Shear Tester RST-01. pc, the Brookfield PFT Powder Flow Tester and the FT4 Powder rheometer. The results showed that the values for the device of one manufacturer did not fully correspond to the values of another one. The flow characteristics of the metal powders were quantified from the particle size distribution data, static angle of repose, and AIFE data. According to the particle size distribution and angle of repose (AOR), 50% of the tested metal powders fell into the free-flowing mode. According to the evaluation of AIFE, 20% of the samples fell into the lower area. Based on the flow indexes calculated from the measurements of the shear devices used, 100% (RST-01.pc), 70% (PFT) and 50% (FT4) of the samples were included in the free-flowing category. When comparing the results, attention should be paid not only to the nature of the material, but also to the methodology and equipment used. A comparison of methodologies revealed similarities in the changing behavior of the different metal powders. A comparison of effective angles of AIFE and static AOR was shown, and a hypothesis of the conversion relation was derived.Web of Science101art. no. 2100