Факультет технічних систем і енергоефективних технологій (ТеСЕТ)
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Item Modeling of Polymer Composite Materials Chaotically Reinforced with Spherical and Cylindrical Inclusions(MDPI, 2022) Берладір, Христина Володимирівна; Берладир, Кристина Владимировна; Berladir, Khrystyna Volodymyrivna; Жигилій, Дмитро Олексійович; Жигилий, Дмитрий Алексеевич; Zhyhylii, Dmytro Oleksiiovych; Гапонова, Оксана Петрівна; Гапонова, Оксана Петровна; Haponova, Oksana Petrivna; Krmela, J.; Krmelova, V.; Артюхов, Артем Євгенович; Артюхов, Артем Евгеньевич; Artiukhov, Artem YevhenovychThe technical and economic efficiency of new PCMs depends on the ability to predict their performance. The problem of predicting the properties of PCMs can be solved by computer simulation by the finite element method. In this work, an experimental determination of the physical and mechanical properties of PTFE PCMs depending on the concentration of fibrous and dispersed filler was carried out. A finite element model in ANSYS APDL was built to simulate the strength and load-bearing capacity of the material with the analysis of damage accumulation. Verification of the developed computer model to predict the mechanical properties of composite materials was performed by comparing the results obtained during field and model experiments. It was found that the finite element model predicts the strength of chaotically reinforced spherical inclusions of composite materials. This is due to the smoothness of the filler surfaces and the lack of filler dissection in the model. Instead, the prediction of the strength of a finite element model of chaotically reinforced cylindrical inclusions of composite materials requires additional analysis. The matrix and the fibrous filler obviously have stress concentrators and are both subject to the difficulties of creating a reliable structural model.Item Modeling and Optimization of Properties of the Environmentally Clean Molds Based on Oligofurfuryloxysiloxanes for the Production the Metal Castings(MDPI, 2022) Ponomarenko, O.; Yevtushenko, N.; Берладір, Христина Володимирівна; Берладир, Кристина Владимировна; Berladir, Khrystyna Volodymyrivna; Zapolovskyi, M.; Krmela, J.; Krmelovа, V.; Артюхов, Артем Євгенович; Артюхов, Артем Евгеньевич; Artiukhov, Artem YevhenovychThis article is devoted to modeling, researching and optimizing the main properties of an environmentally clean polymer composition based on oligofurfuryloxysiloxanes (OFOS), which can be used to produce casting molds and cores in the production of castings from ferrous and nonferrous metals. Polymer compositions were examined for strength, survivability, gas permeability, moisture, crumbliness, fire resistance, knockout, and stickability. It has been established that the increase in the strength of the polymer composition over time obeys an exponential law. Mathematical equations were derived for all the exponential curves. The indications of compressive strength of the polymer composition with OFOS with all the acid catalysts used were, on average, as follows: after 1 h—1.3–1.54 MPa; after 3 h—2.5–2.9 MPa; after 24 h—4.9–6.1 MPa, which meets the requirements for casting molds before pouring with metal. The use of polymer compositions with OFOS ensures environmental safety of the technological process, due to the lack of emission of toxic substances, both in the “cold” stage of the process and during casting with molten metal, cooling, knocking out, and disposal of polymer compositions. This makes it possible to save energy resources, and thereby reduce the total cost of the entire technological process and castings.Item Influence of Nitrocarburizing on Increasing the Service Life of Elastic Elements of Direct Flow Valves(Jan Evangelista Purkyne University in Usti nad Labem, 2021) Krmela, J.; Говорун, Тетяна Павлівна; Говорун, Татьяна Павловна; Hovorun, Tetiana Pavlivna; Берладір, Христина Володимирівна; Берладир, Кристина Владимировна; Berladir, Khrystyna Volodymyrivna; Артюхов, Артем Євгенович; Артюхов, Артем Евгеньевич; Artiukhov, Artem Yevhenovych; Kasian, S.The effect of the nitrocarburizing process in pastes with heating in a chamber furnace on the structure and strength characteristics of 09Cr15Ni8Al corrosion-resistant steel was investigated. The technology of thermochemical treatment was developed, which included nitrocarburizing in pastes with heating in a chamber furnace at different holding times. The thickness of the diffusion layer and its microhardness were determined after nitrocarburizing. To determine the efficiency and select the modes of thermochemical treatment, tests were carried out for the investigated steel's strength characteristics. The main feature of the structure of the diffusion layers of valve steels, obtained by nitrocarburizing in the nitrogencarbon paste, is the presence of an inhomogeneous layer with clearly distinguished zones.Item Determining the main regularities in the process of mineral fertilizer granule encapsulation in the fluidized bed apparatus(PC Technology Center, 2021) Острога, Руслан Олексійович; Острога, Руслан Алексеевич; Ostroha, Ruslan Oleksiiovych; Юхименко, Микола Петрович; Юхименко, Николай Петрович; Yukhymenko, Mykola Petrovych; Bocko, J.; Артюхов, Артем Євгенович; Артюхов, Артем Евгеньевич; Artiukhov, Artem Yevhenovych; Krmela, J.This paper has substantiated the expediency and prospects of obtaining organomineral fertilizers by encapsulating mineral granules with an organic suspension in fluidized bed apparatuses. An overview of existing approaches to the mathematical description of the kinetics of granule growth in granulation processes in fluidized bed apparatuses is presented. A mathematical model of the kinetics of the formation of a hard shell around granules in a fluidized bed has been built. It shows that the kinetics depend on the size of the retour particles, the specific flow rate of the suspension, the density of the suspension and granules, and the time of the process. Equations have been derived for determining the thickness of the hard shell and the specific flow rate of the suspension for individual granulation stages in a multi-stage granulator of the fluidized layer. Analytically, graphical dependences were built, which showed an increase in the thickness of the hard shell due to an increase in the specific flow rate of the suspension, the diameter of the retour particles, and the time of the encapsulation process. The equations make it possible to determine the rational regime and technological parameters of the encapsulation process in order to obtain a coating of the predefined thickness at the surface of the granules. This ensures that a quality product is obtained, with a granulometric composition in a narrower range of particle size. To obtain granules of 2.5–4 mm in size, it is necessary to carry out the process in three- or four-stage granulators of the fluidized bed at specific suspension consumption of (10–20)∙10-4 kg/(kg∙s.). It is shown that with uniform growing of granules with a constant increase in the thickness of the shell in multistage granulators, the suspension consumption decreases by 2‒3 times from the first stage to the subsequent ones. This approach reduces the operating and energy costs of the process.Item Complex designing of granulation units with application of computer and software modeling: case “Vortex granulator”(IOP Publishing, 2020) Артюхов, Артем Євгенович; Артюхов, Артем Евгеньевич; Artiukhov, Artem Yevhenovych; Артюхова, Надія Олександрівна; Артюхова, Надежда Александровна; Artiukhova, Nadiia Oleksandrivna; Krmela, J.; Krmelová, V.The article is devoted to the description of the complex method to design granulation unit, which is based on the joint use of the computer modeling results on the simulation models and software modeling based on author’s software products. The description of the software package Granulation Unit© to carrying out the structural and technological calculations for the granulation unit is given. The role of computer and software modeling in the general design algorithm of the granulation unit is shown. The optimization criteria are selected and an algorithm of design optimization for granulation unit is described using the example of the "Vortex Granulator" case. A general method of granulation unit designing "turnkey" with the use of automated design elements is presented. The results of automated calculations form the base to design an industrial granulation unit for the porous ammonium nitrate production. On the example of a specific product of the granulation unit (porous ammonium nitrate), the author's software product is presented to determine the quality of the porous surface in the granule. This approach in modeling allows to create the automated systems for the optimization calculation of granulation equipment.Item Granulation machines with highly turbulized flows: creation of software complex for technological design(IOP Publishing, 2020) Артюхов, Артем Євгенович; Артюхов, Артем Евгеньевич; Artiukhov, Artem Yevhenovych; Артюхова, Надія Олександрівна; Артюхова, Надежда Александровна; Artiukhova, Nadiia Oleksandrivna; Krmela, J.; Krmelová, V.The article deals with author’s software products review to calculate devices with highly turbulized flows as a part of granulation units. Principal scheme and model of the granulation unit, algorithm of the granulation technical calculation are represented in the work. The complex automated calculation technique of the granulation units is proposed. The proprietary software for calculation of main stages in the granulation process is observed in the research. Short description and functions of main software products to implement basic algorithm are given: Vortex Flow©, Conical Channel©, Conical Granulator©, Multistage Heat Treatment©, Vortex Tray©. As a result of the optimization calculation, the user of programs will get the following information: optimal construction of the vortex granulator’s workspace, necessary number of stages in the multistage shelf drier for granules’ final drying, number and construction of the vortex tray with heat and mass transfer separation elements for exhaust gases cleaning. All software products enable to export the received data and to exchange these data between each other. The complex algorithm and software products, proposed in the article, let to carry out optimization calculation of the main technological equipment in the granulation unit at its designing stage without expensive multifactorial experiment. The presented granulation units’ calculation algorithm and software products for its realization enable to carry out equipment changeover if raw material characteristics and the productivity of the unit are changed. The automated calculations results give a base to design industrial granulation unit for porous ammonium nitrate production.Item Increasing the Structural Strength of Corrosion-resistant Steel for Elastic Components of Diaphragm Compressor(Jan Evangelista Purkyne University in Usti nad Labem, 2021) Krmela, J.; Говорун, Тетяна Павлівна; Говорун, Татьяна Павловна; Hovorun, Tetiana Pavlivna; Берладір, Христина Володимирівна; Берладир, Кристина Владимировна; Berladir, Khrystyna Volodymyrivna; Артюхов, Артем Євгенович; Артюхов, Артем Евгеньевич; Artiukhov, Artem YevhenovychThe design features of diaphragm compressors are discussed in this article. For preventing the formation of local stresses in certain areas of the diaphragm, it is recommended to use thin sheet stainless steel of the transition class. A comparative analysis is made of two batches of steel tape, differing in the value of the saturation magnetic induction, which is identical to the content of the martensite phase in the structure of the material before the final cycle of cold plastic deformation. The results of the study of the influence of the deformation temperature (20 – 300 ºС) on the change in mechanical properties (σb, σ0.2, δ) revealed a different tendency to embrittlement of the material of the tapes for these batches. For increasing the operational reliability of the compressor's diaphragm elements, it is recommended to use a material, the structure of which contains a certain amount of work-hardened retained austenite. This makes it possible to undergo additional martensitic transformation under the action of peak loads in local areas and increases the structural strength of corrosion-resistant steel for the manufacture of a compressor diaphragm.Item Multistage Shelf Devices with Fluidized Bed for Heat-Mass Transfer Processes: Experimental Studies and Practical Implementation(MDPI, 2021) Юхименко, Микола Петрович; Юхименко, Николай Петрович; Yukhymenko, Mykola Petrovych; Артюхов, Артем Євгенович; Артюхов, Артем Евгеньевич; Artiukhov, Artem Yevhenovych; Острога, Руслан Олексійович; Острога, Руслан Алексеевич; Ostroha, Ruslan Oleksiiovych; Артюхова, Надія Олександрівна; Артюхова, Надежда Александровна; Artiukhova, Nadiia Oleksandrivna; Krmela, J.; Bocko, J.The article deals with the theoretical description and experimental study of the hydrodynamic and heat transfer properties regarding the operation of multistage gravitational devices of the fluidized bed with inclined perforated shelves. The peculiarities of the work and the implementation field of the multistage shelf units are described. A theoretical model to define the solubilizer’s velocity above the perforation holes, in the above-shelf space of the device and in the outloading gap, as well as the residence time of the dispersed phase at the stage (perforated shelf contact) of the device is presented. The results of experimental studies regarding the influence, made by the structural parameters of the perforated shelf contacts, on the distribution pattern of single-phase and gas-dispersed flows in the workspace of the device, on the intensity of interphase heat transfer are presented. The conditions to create active hydrodynamic operating modes of multistage gravitational shelf devices, which provide higher efficiency of heat-mass transfer processes, and with lower gas consumption and hydraulic resistance compared to typical fluidized bed devices, are proved. Peculiarities regarding the implementation of heat-mass transfer processes in multistage devices are described using heat treatment and drying processes as examples.Item Calculation of the Characteristics of the Multi-gap Seal of the Centrifugal Pump, in Dependence on the Chambers’ Sizes(Manufacturing Technology, 2020) Позовний, Олександр Олександрович; Позовный, Александр Александрович; Pozovnyi, Oleksandr Oleksandrovych; Загорулько, Андрій Васильович; Загорулько, Андрей Васильевич; Zahorulko, Andrii Vasylovych; Krmela, J.; Артюхов, Артем Євгенович; Артюхов, Артем Евгеньевич; Artiukhov, Artem Yevhenovych; Krmelová, V.The paper presents the results of an experimental research and a numerical calculation of a multi-gap seal of a centrifugal pump. The experimental research allowed to obtain the characteristics’ performance of the multi-gap seal at different operating modes, in dependence on the axial size of the chambers, pressure distributions’ changes, and a leakage from the seal. Using finite volume methods, values of radial hydrostatic forces, pressure distributions and leakage values were obtained. The results of the numerical calculation were compared with the results of the experiment, which showed that they matched.Item Minimization of Soil Pollution as a Result of the Use of Encapsulated Mineral Fertilizers(Bentus, 2020) Вакал, Сергій Васильович; Вакал, Сергей Васильевич; Vakal, Serhii Vasylovych; Яновська, Ганна Олександрівна; Яновская, Анна Александровна; Yanovska, Hanna Oleksandrivna; Вакал, Вікторія Сергіївна; Вакал, Виктория Сергеевна; Vakal, Viktoriia Serhiivna; Артюхов, Артем Євгенович; Артюхов, Артем Евгеньевич; Artiukhov, Artem Yevhenovych; Школа, Вікторія Юріївна; Школа, Виктория Юрьевна; Shkola, Viktoriia Yuriivna; Yarova, T.; Dmitrikov, V.; Krmela, J.; Malovanyy, M.The application of nitrogen fertilizers allows increasing crop yields and partially increase the natural soil fertility. They have a negative influence on the environment due to the significant release of nitrogen. Hence, the technology for decreasing the N-release is proposed in this work. Obtaining of complex organo-mineral NPK fertilizers by encapsulating a carbamide granule with a phosphate-potassium shell with humates is the main aim of this work. The main tasks of this shell is slow release of the nitrogen and phosphate nutrients from the granules into the soil following the agrochemical needs of plants and prevention of soil pollution. The powdered components agglomeration of phosphate and potassium fertilizers with a small amount of liquid phase (plasticizer) allows forming a phosphate-containing coating on a carbamide core by means of the semi-dry method. This innovation allows organizing the production of such a product at the average enterprise with less capital investment. Carbamide prills, phosphate-glauconite concentrate, calcium and potassium ballast humate, and “Avatar” trace-element chelate complex were used in experimental studies. A preliminary assessment of the market prospects for such an innovation shows a high level of market attractiveness for all market participants: producers, consumers, and society