scholarly journals Change of Pressing Chamber Conicalness at Briquetting Process in Briquetting Machine Pressing Chamber

10.14311/1554 ◽  
2012 ◽  
Vol 52 (3) ◽  
Author(s):  
Peter Križan ◽  
Miloš Matúš ◽  
Jaan Kers ◽  
Djordje Vukelić

In this paper, we will present the impact of the conical shape of a pressing chamber, an important structural parameter. Besides the known impact of the technological parameters of pressing chambers, it is also very important to pay attention to their structural parameters. In the introduction, we present a theoretical analysis of pressing chamber conicalness. An experiment aimed at detecting this impact was performed at our institute, and it showed that increasing the conicalness of a pressing chamber improves the quality of the final briquettes. The conicalness of the pressing chamber has a significanteffect on the final briquette quality and on the construction of briquetting machines. The experimental findings presented here show the importance of this parameter in the briquetting process.

Author(s):  
Андрей Киричек ◽  
Andrey Kirichek ◽  
Дмитрий Соловьев ◽  
Dmitriy Solovyev ◽  
Александр Хандожко ◽  
...  

The problems of analyzing metallographic images and the method of their solution using modern software for the analysis of metallographic images are described. There is given an analysis of microstructure images as the main indicator of the surface layer quality by the example of studying the research results of strain wave hardening combinations and chemical-thermal treatment, in particular the influence of previous strain wave hardening and subsequent thermal and chemical- thermal treatment on the alloy steel microstructure or previous thermal and chemical- thermal treatment and subsequent strain wave hardening. On the basis of the analysis the effectiveness of strain wave hardening and chemical and thermal treatment is established.


Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1941
Author(s):  
Aurel Tulcan ◽  
Mircea Dorin Vasilescu ◽  
Liliana Tulcan

The objective of this paper is to determine how the supporting structure in the DLP 3D printing process has influences on the characteristics of the flat and cylindrical surfaces. The part is printed by using the Light Control Digital (LCD) 3D printer technology. A Coordinate Measuring Machine (CMM) with contact probes is used for measuring the physical characteristics of the printed part. Two types of experiment were chosen by the authors to be made. The first part takes into consideration the influence of the density of the generated supports, at the bottom of the printed body on the characteristics of the flat surface. In parallel, it is studying the impact of support density on the dimension and quality of the surface. In the second part of the experiment, the influence of the printed supports dimension on the flatness, straightness and roundness of the printed elements were examined. It can be observed that both the numerical and dimensional optimum zones of the support structure for a prismatic element could be determined, according to two experiments carried out and the processing of the resulting data. Based on standardized data of flatness, straightness and roundness, it is possible to put in accord the values determined by measurement within the limits of standardized values.


2021 ◽  
Vol 2 (1 (110)) ◽  
pp. 70-80
Author(s):  
Oleksii Vambol ◽  
Andrii Kondratiev ◽  
Svitlana Purhina ◽  
Maryna Shevtsova

The mass application of FDM technology is slowed down due to the difficulty of selecting 3D printing parameters in order to manufacture an article with the required characteristics. This paper reports a study into the impact of 3D printing parameters (temperature, print speed, layer height) on mechanical parameters (strength, elasticity module), as well as on the accuracy of printing and roughness of the surface of a specimen based on thermoplastic (PLA plastic). Several batches of specimens were fabricated for this study in accordance with ASTM D638 and ASTM D695, which were tested for tension, geometric accuracy, and roughness. Based on the experimental data, regression analysis was carried out and the functional dependences of the strength, elasticity module, printing precision, roughness of a surface on 3D printing parameters (temperature, speed, thickness of the layer) were constructed. In addition, the derived mathematical model underlying a method of non-linear programming has established such printing parameters that could provide for the required properties of a structure. The analytical dependences reported in the current work demonstrate a high enough determination factor in the examined range of parameters. Using functional dependences during the design phase makes it possible to assess the feasibility of its manufacture with the required properties, reduce the time to work out the process of printing it, and give recommendations on the technological parameters of 3D printing. The recommendations from this study could be used to make PLA-plastic articles for various purposes with the required properties


2014 ◽  
Vol 54 (1) ◽  
pp. 28-34 ◽  
Author(s):  
Monika Kováčová ◽  
Miloš Matúš ◽  
Peter Križan ◽  
Juraj Beniak

The quality of a high-grade solid biofuel depends on many factors, which can be divided into three main groups - material, technological and structural. The main focus of this paper is on observing the influence of structural parameters in the biomass densification process. The main goal is to model various options for the geometry of the pressing chamber and the influence of these structural parameters on the quality of the briquettes. We will provide a mathematical description of the whole physical process of densifying a particular material and extruding it through a cylindrical chamber and through a conical chamber. We have used basic mathematical models to represent the pressure process based on the geometry of the chamber. In this paper we try to find the optimized parameters for the geometry of the chamber in order to achieve high briquette quality with minimal energy input. All these mathematical models allow us to optimize the energy input of the process, to control the final quality of the briquettes and to reduce wear to the chamber. The practical results show that reducing the diameter and the length of the chamber, and the angle of the cone, has a strong influence on the compaction process and, consequently, on the quality of the briquettes. The geometric shape of the chamber also has significant influence on its wear. We will try to offer a more precise explanation of the connections between structural parameters, geometrical shapes and the pressing process. The theory described here can help us to understand the whole process and influence every structural parameter in it.


2021 ◽  
pp. 98-106
Author(s):  
M. Chobotko ◽  
I. Chobotko

Purpose: to analyze the impact of the use of digital technology in judging to correctly identify the winner in judo competitions. Material and methods. The following methods were used during the research: theoretical analysis and generalization of literature sources and data of the Internet, analysis of video recording, methods of mathematical statistics. Results: based on the recordings of 42 fights of the final block of the European Championship and the Ukrainian Junior Judo Championship on video hosting (You Tube), the analysis of the impact of video replays on the referee's decision was conducted to correctly identify the winner in the competition. In 22 bouts of the European Championship and in 24 bouts of the Ukrainian Championship, the referees made decisions that did not require revision or change. In the other 20 fights of the European Championship and in 18 fights of the Ukrainian Championship, video replays were used. A comparison of the average rates of fights in which digital replays were used or not used with the help of digital technologies showed a statistically significant difference in the performance of refereeing at the European Championship and the Ukrainian Judo Championship among juniors (<0,05). Since t (0,051) < tgr (1,98) the analysis of the refereeing of the European Championship and the Ukrainian Junior Judo Championship can be considered statistically significant. As a percentage of the total number of 42 fights, of which 20 fights – 47,6 % of international judges use video replays and 22 fights – 52,3 % of international judges did not use video replays. Analyzing the championship of Ukraine with a total of 42 fights, of which 18 fights – 42,8 % of judges use video replays and 24 fights – 57,1 % of judges did not use video replays. Conclusions. Analysis of existing digital technologies used in judo refereeing has revealed a set of programs that assist in the competition. The use of digital technologies provides an opportunity to improve the quality of refereeing at various ranks of the competition. The percentage of using video views and the percentage without video views at the European Championship and the Ukrainian Championship is almost the same. This speaks to the quality of judging at these events. This is because the refereeing of the final block allows more qualified judges who did not make mistakes during the refereeing or these mistakes were minimal. Keywords: judo, digital technologies, video replays, YouTube, European Championship, Ukrainian Championship, judges.


2020 ◽  
Vol 26 (2) ◽  
pp. 49-53
Author(s):  
Emil Spišák ◽  
Janka Majerníková ◽  
Ľuboš Kaščák ◽  
Peter Mulidran

The quality of the sheared surface when blanking, also known as die-cutting, is the result of several factors. Based on current knowledge about blanking, the following technological parameters – shear gap size, blunting of the shearing tool, lubrication in the shearing process, and deformation rate – can be considered as decisive parameters on the quality of the sheared surface. The main material characteristics include yield strength, tensile strength, ductility, and ferrite grain size. The paper is focused on the influence of the shear gap on the quality of the shear surface of electrical sheets with different chemical composition and different mechanical properties. The quality of the cutting surface was characterized by the size of the plastic cutting area. The relationships between the size of the shear gap, which ranged from 1 to 7% of the thickness of the cut material and the size of the plastic shear area, were evaluated and measured macroscopically.


2015 ◽  
Vol 15 (3) ◽  
pp. 43-46 ◽  
Author(s):  
B. Opyd ◽  
K. Granat

Abstract The paper presents the results of basic research on the influence of the properties of sand grains on electrical properties of water glass moulding sands. It shows electrical properties of the main component – sand grains, crucial to the kinetics of moulding sands heating, such as permittivity εr and loss factor tgδ. Measurements were carried out with the use of the perturbation method for silica, chromite and olivine sands of different mineral, chemical composition and particle size distribution, as well as for moulding sands with water glass grade 145. Analysis of the results of measurements of electrical properties shows that all moulding sands are characterized by a similar permittivity εr and loss factor tgδ. It was found that the electrical properties and the quantity and quality of other components may have a decisive influence on the effectiveness and efficiency of the microwave heating of moulding sands with sand grains. In determining the ability to efficiently absorb the microwave radiation for mixtures which moulding sands are, the impact of all components influencing their individual technological parameters should be taken into account.


1970 ◽  
Vol 52 (2) ◽  
pp. 469-479 ◽  
Author(s):  
A. M. RIJKE

1. The water repellency of feathers is determined mainly, but not exclusively, by a structural parameter which can be expressed in terms of diameter and spacing of the barbs and barbules. 2. Effective waterproofing properties result from the optimal balance of structural parameter and resistance to water penetration. 3. Comparison of the structural parameters for water birds with the geological time interval of their earliest fossil record shows a phylogenetic tendency toward optimizing waterprooftng properties with the course of time. 4. Several behavioural patterns are discussed which may have evolved under the selective pressure of the quality of water repellency and resistance to water penetration.


2021 ◽  
Vol 282 ◽  
pp. 07023
Author(s):  
M.N. Salikhova ◽  
V.A. Aleksandrov ◽  
V.S. Kukhar ◽  
I.P. Galchak ◽  
A.M. Chudinov

In order to identify the regularities of further increasing the efficiency of transport and technological machines, it is of interest to consider the issues of determining the impact of their design and technological parameters on the quality of running-in and the operability of fuel pumps. The article analyzes the influence of the initial operating modes and the lubricating medium on the quality of running-in and subsequent performance of high-pressure fuel pumps. On the basis of theoretical studies, equations were obtained to determine the unbalanced radial force acting on the plunger and fuel leaks in the plunger pair. These expressions make it possible to establish the dependence of the specific pressure in the plunger and barrel assembly both on the design and technological parameters of the pump.


2017 ◽  
Vol 57 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Renata Butkutė ◽  
Martynas Skapas ◽  
Algirdas Selskis ◽  
Virginijus Bukauskas ◽  
Sandra Stanionytė ◽  
...  

Crystallographic properties of AlAs barriers in GaAsBi-based multi-quantum well structures grown on GaAs substrates by molecular beam epitaxy (MBE) and migration-enhanced epitaxy (MEE) were studied. The quantum wells were grown at temperatures ranging from 160 to 350 °C. The width of GaAsBi quantum wells varied from 4 to 20 nm. The optimization of technological parameters for the growth of high crystalline quality AlAs barriers at low temperatures was performed. To explore the impact of high temperature treatment on crystal quality, surface roughness and chemical composition stability, ex situ rapid thermal annealing was performed at 650–750 °C for 180 s in nitrogen ambiance. The structural quality of AlAs barriers, the morphology and sharpness of the interfaces between GaAsBi quantum wells and AlAs barriers were studied by high resolution X-ray diffraction, atomic force microscopy and high resolution transmission electron microscopy, respectively. In this study it was demonstrated that MEE allows one to achieve higher crystal quality of AlAs barriers at much lower temperatures in comparison to MBE. The blocking of Bi out-diffusion from the GaAsBi quantum wells toward the surface was shown for both MBE and MEE grown AlAs barriers.


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