Parameters Of Technological Process Research Articles

Formation of Corrosion‐Resistant Nitride Coatings Based on Ti–Al–Cr–Fe–Ni High‐Entropy Alloy

The purpose of the work is to study the features of the phase and structure formation of coatings (Ti–Al–Cr–Fe–Ni)N formed by vacuum arc deposition and to study the influence of technological parameters of the deposition process on their corrosive properties. It is established that on the basis of the selected elements, it is possible to form a high‐entropy compound in the form of a solid solution. The structure of nitride coatings based on high‐entropy compounds formed by vacuum arc deposition is studied. It is established that the phase composition of coatings largely depends on the ratio of titanium and aluminum, which is determined by the technological parameters of deposition. An analysis of the results of the electrochemical behavior of coatings (Al,Ti,Fe,Cr,Ni)N shows that an increase in the corrosion resistance of these coatings is due to the synergistic effect of the formation of a solid substitution solution with a dense nanoscale structure and an increased relative aluminum content in them.

ТЕХНОЛОГІЇ ХОЛОДНОГО РЕСАЙКЛІНГУ ДЛЯ ГЛИБОКОЇ РЕГЕНЕРАЦІЇ НЕЖОРСТКОГО ДОРОЖНЬОГО ОДЯГУ

ntroduction. In the introduction to the article, the briefly performed comparative analysis of the road asphalt concrete cold recycling technologies was adduced and also the actuality of the implementation of widened nomenclature of such technologies in the Ukraine was outlined. Problem statement. The issue of the article concerns processes and materials for technologies of the full-depth reclamation of flexible road pavements using cold recycling trough full depth of asphalt layer/layers including the underlying layers of granular materials as required. Purpose. The aim of the article is to analyze the technological parameters of processes of full-depth reclamation (FDR) and also general requirements for reclaimed materials especially those concerning the estimation of their thermorheological properties. Results. The methods of the reclaimed materials stabilization were examined which, in accordance with the FDR technologies, should be divided in mechanical and those performed with the stabilizing agents. The types of pavement defects were defined under presence of which the application of FDR technologies has been recognized highly effective. The concise analysis of general requirements for reclaimed materials was performed with setting off the materials subjected to special requirements for grading. Also, the technological particularities of processes of the full-depth reclamation were stated which should be attributed to the technical characteristics of road equipment, the road pavement condition, and reclaimed mixtures quantitative proportions as well. According to the analysis of the test methods of reclaimed materials stabilized by bitumen using foamed bitumen, the role of the thermoreological uniformity of cold recycled mixtures for their proper design was shown.

Повышение ресурса рабочих колес центробежных насосов шахтного водоотлива

Mining The article discusses the main failure causes of centrifugal pumps used in the mine dewatering plants. The factors causing intensive wear of the impellers used in centrifugal pumps of the CNS-33-66...330 type are analysed, as well as the ways of increasing their serviceability. The gas dynamic cold spraying is recognized as the most promising and efficient method of applying functional coatings, which makes it possible to improve the condition of the surface layer and eliminate surface defects of the initial impeller blanks, which have a significant impact on the serviceability of the parts. The main research trends are outlined in the studied area, and practical recommendations are provided on using the gas dynamic cold spraying methid both in the pump manufacturing process and in their overhaul. It is shown that one of the promising trends in development the gas dynamic cold spraying applications is the creation of multilayer coatings on the impeller blades based on compositions of various metal-ceramic powders. Along with the hardening treatment, this combination will allow to provide the impellers with a set of necessary functional characteristics for the hydro-abrasive wear conditions. technological process as a sequence of changing the natural state of the Earth's subsoil to obtain a certain quantity and quality of mineral products is characterized by departures from the specified normative parameter values, which is due to causes of different nature. Most of these causes are man-made, anf they are created during the performance of specific process operations by the personnel. The article presents an original approach to managing the control over the technological process parameters in a coal strip mine. To reduce the magnitude and probability of the process departures from the normative values, the authors propose to create technical and organizational control loops. Each loop is a closed chain of technical means and organizational tools, which secures up-keeping of the normative technological process state. Production risk is proposed to be used as a criterion to assess the efficiency of the control loops. The methodology allowing to calculate the risk is described. The results of the contour approach application to the technological process control at the Solntsevsky coal strip mine are presented.

Формирование контуров контроля технологического процесса угольного разреза

Mining technological process as a sequence of changing the natural state of the Earth's subsoil to obtain a certain quantity and quality of mineral products is characterized by departures from the specified normative parameter values, which is due to causes of different nature. Most of these causes are man-made, anf they are created during the performance of specific process operations by the personnel. The article presents an original approach to managing the control over the technological process parameters in a coal strip mine. To reduce the magnitude and probability of the process departures from the normative values, the authors propose to create technical and organizational control loops. Each loop is a closed chain of technical means and organizational tools, which secures up-keeping of the normative technological process state. Production risk is proposed to be used as a criterion to assess the efficiency of the control loops. The methodology allowing to calculate the risk is described. The results of the contour approach application to the technological process control at the Solntsevsky coal strip mine are presented.

Building a model of the abrasion grinding mechanism in a tumbling mill based on data visualization

The object of this study is the grinding process in a tumbling mill when the mechanism of destruction by abrasion is implemented, which is caused by the mechanism of shear loading. The abrasive effect due to the impulse interaction during the mutual chaotic movement of granular particles in the shear layer of loading, characterized by the granular temperature, is taken into account. The task solved was determining the parameters of the shear interaction, which is caused by the difficulties of modeling and complexity of the hardware analysis of behavior of the internal loading in the mill. A mathematical model was built based on data visualization for the abrasion grinding mechanism. The power of the shear interaction forces was taken as an analog of the grinding performance. The initial shear characteristic was considered to be the average value of the shear velocity gradient in the central averaged normal section of the shear layer. The impact on productivity of the granular temperature and mass fraction of the shear layer and loading turnover was taken into account. The effect of rotation speed on performance was evaluated by experimental modeling at a chamber filling degree of 0.45 and a relative particle size of 0.0104. The maximum value of the energy and productivity of grinding by abrasion was established at the relative speed of rotation ψω=0.55–0.6. The results have made it possible to establish a rational speed when grinding by abrasion, ψω=0.5–0.6. This value is smaller in comparison with grinding by crushing ψω=0.55–0.65 and breaking ψω=0.75–0.9. The established effect is explained by the detected activation of the chaotic quasi-thermodynamic movement of particles of the shear layer at slow rotation. The model built makes it possible to predict rational technological parameters of the energy-saving process of fine grinding in a tumbling mill by abrasion

ДОСЛІДЖЕННЯ ТЕХНОЛОГІЧНИХ ПОКАЗНИКІВ РОБОТИ ВІБРАЦІЙНОГО ГРОХОТА З ЕЛАСТИЧНИМИ СИТАМИ

In the metallurgical branch of industry, the problems of separation according to the given size - screening of the original metallurgical raw materials, in particular coke, are relevant. This ensures high-quality operation of the technological equipment of blast furnaces and supply of blast furnace coke of regulated size. In this regard, research is constantly being conducted and the development of new methods of screening and modernization of devices to improve the performance of vibrating screens continues. The purpose of the scientific work: an experimental study of the technological parameters of the vibration screen with elastic sieves. The paper gives a description of the laboratory vibrating sieve with an elastic sieve, which is used in the research. An experimental study of the technological parameters of the screening process of the vibrating screen was carried out and the dependence of the technological indicators on the parameters of the vibrating screen was constructed. It has been shown that the highest screening efficiency is observed at oscillation frequencies in the range of 22-27 Hz. At these frequencies, the efficiency indicators of the screening process vary between 78-90%. A change in the value of the specific load from 10 t/(h m^2) to 16 t/(h m^2) causes a gradual decrease in the screening efficiency from 90% to 65%.

Influence of Vertical Straightener Roller Shape on Residual Stress Level in Railway Rails

The required rail straightness is achieved by straightening with roller straighteners. The consequence of the straightening operation is the introduction of residual stresses to the straightened rail. An excessive level of residual stresses accumulated in the rail during use in the track may lead to its damage or fracture. ArcelorMittal Poland S.A., in cooperation with Łukasiewicz Research Network – Institute for Ferrous Metallurgy, carried out a research project (POI R.01.02.00-00-0167/16) the aim of which was to reduce residual stresses in railway rails by changing the technological parameters of the straightening process. The results of the presented study relate to rails 60E1 and 60E2. The study includes the measurement, testing, calculations and analyses of the obtained results. The conducted research indicates the possibility of obtaining a low level of residual stress in the rails for a system consisting of a 7-roller vertical straightener and a 9-roller horizontal straightener by changing the roller settings, the shape of the rollers, the shape of the rail foot and its curvature.

MULTIFACTOR ANALYSIS OF THE EFFICIENCY OF THE FERROALLOY PROCESS

Ore-reducing ferroalloy processes must be considered as a relationship of parameters and characteristics of subsystems and elements. The maximum energy capacity of the furnace and its productivity is achieved both due to the design parameters of the bath, the short network, the power of the furnace transformer, the diameter of the self-ignition electrodes, as well as the electrotechnological and thermophysical properties of the initial charge materials, ore-slag melt and final ferroalloy. The amount of carbon is one of the most significant technological parameters of the carbon reduction process for the production of manganese ferroalloys. In the work, the most significant final indicators are adopted and their correlation with electrical characteristics and technological parameters is determined.

Research on the production technology of rubber epoxy from concentrated natural rubber latex

The results of research on epoxidation technology from concentrated natural rubber latex (CNRL) and in-situ peroxyformic acid, which is synthesised from formic acid (FA) and hydrogen peroxide (HP), are presented in the article. The study investigated the influence of technological parameters of the epoxidation process, such as stabiliser content (nonylphenol ethoxylate, NP9), dry rubber content (DRC), isoprene, stirring speed, reaction time, reaction temperature, and molar ratios of hydrogen peroxide and isoprene (IP), on the epoxy resin content of the product. Research results have shown that the epoxidation reaction with NP9 at 10% takes from 2.5 to 20 hours under the following conditions: latex composition contains from 16 to 24% DRC, stirring speed 100 rpm, reaction temperature response 30 to 70 °C, HP/IP molar ratio changes from 0.7 to 1.3, FA/IP ratio is 0.2, the product was stable and without coagulation. The product was obtained with an epoxy content of 23.4 to 43.6%. This is the basis for building an epoxidized natural rubber (ENR) production process to create a series of natural rubber products that are renewable, environmentally friendly, low-cost, and have many industrial applications.

SMART DEVICE FOR PET RECYCLING

PET (polyethylene terephthalate) is a common plastic substance used to make water bottles, carbonated drinks, juices and others. PET is durable and easy to transport, but can be difficult to degrade in nature. If not recycled, PET can remain in the environment for hundreds of years, polluting the sea and other environmental areas. The work presents the creation of an smart device, which can easily, with low costs, be transformed in laboratory conditions, respecting the steps of the industrial technological process, of polyethylene terephthalate (PET) into recycled PET. The final goal is to research the mechanical characteristics of recycled PET. The method used is Computer Assisted Thermoplastic Extrusion, the main parameters of the entire technological process being permanently monitored. The results of mechanical and thermal tests were demonstrated that recycled PET can be transformed into filament for 3D printing of finished products that have properties similar to those obtained industrially.

Evaluation of the activity of amine hardeners of epoxy resins

With the appearance of new epoxy resins and amines, which are widely used for hardening epoxy compositions using energy-saving technology (at "ordinary" temperatures), on the world market, the targeted selection of these materials to provide the desired technological and operational properties becomes relevant. In order to predictively choose amine hardeners for epoxy resins, their quantum-chemical calculations were performed using the semi-empirical parameterized 3 (PM3) method. The energy value of the highest occupied molecular orbital (HOMO) of amines and the absolute value of the energy gap || (the absolute difference in energies between the HOMO of amines and the lower vacant molecular orbital (LUMO) of epoxy resins) were used. The relationships between the absolute value of the energy gap || and the main technological parameters of the curing process of dian epoxy resin ED-20 with individual amines were established with pairwise correlation coefficients of not less than 0.977. The evaluation of the activity of modified polyamines and their mixtures in hardening epoxy resins is proposed to be carried out based on the maximum temperature of the exothermic reaction of interaction between the epoxy groups of resins and the amine groups of hardeners. The possibility of adjusting the temperature of the exothermic hardening reaction of epoxy compositions and their "viability" time by introducing epoxy-containing diluents with different values of the LUMO energy was shown.

A novel geometric predictive algorithm for assessing compressive elastic modulus in MEX additive processes, based on part nonlinearities and layers stiffness, validated with PETG and PLA materials

MEX (Material Extrusion) is an intrusive technological process that inherently induces alterations in the elastic and mechanical parameters of plastic materials. Manufacturers provide initial mechanical parameters for plastic filaments, which undergo modifications during MEX manufacturing, influenced by intrinsic manufacturing factors such as temperature and pressure changes, as well as geometric and technological parameters of the 3D additive process. These factors, compounded by the inherent geometric nonlinearities in plastic components, directly impact the post-manufacture mechanical and elastic properties of the material. Presently, material characterization in MEX manufacturing relies on manual experimental testing, necessitating new tests for any variation in manufacturing parameters. In this scenario of mechanical uncertainty, rigorously validating component behavior involves costly experimental trials. Intending to solve the problems of MEX components manufacturing, the paper presents an innovative methodology based on the use of a new predictive algorithm created by the researchers capable of obtaining the elastic modulus of a plastic material manufactured with MEX and its mechanical behavior in the elastic zone under compressive loads. The predictive algorithm only needs as input the compressive elastic modulus of the isotropic plastic material filament and the manufacturing parameters of the MEX process. The smart developed algorithm calculates the stiffness of each layer considering the number of holes in the projected area. The innovative predictive algorithm has been experimentally and numerically validated using PETG (Polyethylene Terephthalate Glycol) material and PLA (Polylactic Acid) on test specimens and on a case study of variable topology. The results show deviations from [0.2%–4.3%] for PETG and [0.4%] for PLA concerning the experimental tests and [1.1%–13.5%], to the numerical analyses. In this line, the presented algorithm greatly improves the results obtained by the simulation software since this software currently can not consider the geometric and technological parameters associated with the 3D manufacturing process of the component. The predictive algorithm is valid for each print pattern and manufacturing direction. The new algorithm improves the existing state of the art significantly since this algorithm extends its utility to most plastic polymer materials suitable for MEX 3D printing, provided that the mechanical and elastic properties of the filament are known. Its versatility extends to complex component geometries subjected to uniaxial compression loads, eliminating the need for mechanical analysis software or expensive experimental validations.

A Cleaning of Internal Surfaces of Bunkers Without the Presence of Operating Personnel Inside the Bunker

Abstract Bunkers are an integral part of the infrastructure of enterprises in various industries processing bulk materials. Corrosion processes and the formation of dust deposits on the internal surfaces of bunkers are irreversible and often lead to disruptions in the technological process and equipment performance parameters, and in some cases, to accidents. The stability and continuity of technological processes for processing bulk materials largely depend on the cleanliness of the internal surfaces of bunkers. Even the best technical characteristics of technological equipment only indicate the technical capabili-ties of the operation of technological lines. Their reliable and effective operation can be ensured by proper maintenance of the condition of internal surfaces and cleaning from corrosion and deposits. Increased dustiness, poor visibility, and confined spaces significantly complicate the conditions for performing work by service personnel inside bunkers. The enclosed space inside bunkers is a very dangerous place not intended for the work of service personnel. In order to avoid endangering ser-vice personnel and prevent people from entering the bunker, methods are proposed to easily, quickly, and, most importantly, safely clean the surfaces inside the bunkers.

Innovative thermodynamic modeling for enhanced yeast dough mixing: energy perspectives and applications

A thermodynamic model for the calculation of energy exchange in the chamber of a new mixer with effective use of structural and technological parameters of the mixing process without the necessary introduction of experimental data correlations in the distribution of fluid velocities is proposed, which determines the relevance of this direction of calculation with the perspective of its development. The purpose of the presented work is to determine the specific power by substantiating the effective mode parameters of the preparation of the mixture (dough) as a result of evaluating the thermodynamic energy parameters of the kneading process. The assessment was carried out by developing a methodology for determining specific costs for creating a viscous medium when mixing components, which allows you to establish the required power depending on the design and technological parameters of the new mixer. The considered principle of the proposed open-type thermodynamic system of the description of the working process of mixing made it possible to reveal and determine the ways of converting energy into useful work of interphase heat and mass transfer of a heterogeneous medium. In the conditions of circulation mixing with multiple mechanical effects on the mixture of components in the closed circuit of the cylindrical working chamber, which is an effective way to achieve homogeneity of the environment, it was possible to obtain an analytical determination of the specific work and power of the drive in the absence of a clear description of the model of the interconnection of components. The proposed thermodynamic description of the system's energy balance allows to perform only a few experiments. In general, the practical value of the given calculations is of practical importance for improving productivity and efficiency and minimizing energy consumption for the process while reducing the dynamic loads of the designed mixer.

Прогнозирование и оценка триботехнической эффективности азотированного слоя деталей машин

Following the laws of tribology and tribotechnics, also the results of experimental studies of reality of structure and properties change in the zone of contact tribodeformation of structural steels and alloys of different structural classes subjected to nitriding, an approach to forecasting and comprehensive assessment of the tribotechnical efficiency of nitriding of structural materials and products made of them has been developed. Analysis of the patterns of changes in the structure of the diffusion zone of nitriding steels: abnormal, martensitic and austenic, and relative wear resistance tests, taking into account their composition and technological parameters of the treatment process, showed that maximum wear resistance was provided by a nitration coating containing hardening dispersed particles of incoherent nitrides, ensuring a lower liability to brittle behavior of the nitration case due to low level of matrix level microdeformation. At the same time, preliminary types of treatment (thermal treating and deformation processing) of nitriding steels contribute to structural and phase state of the surface layer, which has added tribological performance. For nitrided ferroalloys with different matrix lattices, the most significant characteristics of the structural state and properties of the surface layers affecting the level of surface fracture under friction have been found empirically: the particle size of nitrides of alloying elements, the distance between them, the density of their distribution, the matrix lattice microdeformation, the values of X-ray lines intrinsic broadening for structural components of the material in the friction deformation zone, the hardness of the nitration case and its changes under friction. These experimental results are taken as a principle of the proposed method for forecasting and assessment of metal tribotechnical efficiency. This principle of method is based on a tribological criterion containing micro- and macroscopic characteristics of the material in the zone of contact deformation under friction, the choice of fabricating methods for the product takes place to ensure an acceptable level of wear intensity. Then, by measurement, using surface large deformation method, the ability of the nitration case formed as a result of treatment according to the selected treatment schedule to perceive surface nondestructive plastic deformation is evaluated. It affords a basis for the selected nitriding treatment schedule. The completion of the assessment is the determination of the values of the maximum operability of the nitriding material under conditions of friction and wear (alarm pressure when a tribocouple operates steadily; critical pressure when it is inoperable, but its operation is possible with short-term overloads; the average total wear intensity of the couple combined). The totality of the identified parameters allows recommending the material, its working and predicting operating modes and durability of tribounit.

Исследование влияния элементов режима и шага зубьев фрезы на технологические параметры и температурное поле процесса обработки заготовок тонкостенных деталей

When machining workpieces of thin-walled parts, the temperature field differs from the field, which is formed during massive workpieces treatment. The reason for this is that machining of a thin-walled billet is interfered with its surface, being opposite to the one under machining. It has a significant effect on the temperature field, since the intensity of heat removal from this surface into the environment is significantly less than heat removal into the underlying layers of a massive material blank. In this regard, the problem of finding a rational mode of the machining process of thin-walled workpieces is relevant. The aim of the study is to determine the effects of the elements of the milling mode of thin-walled workpieces and milling cutter teeth space on the technological parameters of the milling process of titanium alloy workpieces and to develop recommendations for choosing this milling mode. For this purpose, a numerical modeling of the technological parameters of the milling process of blanks of massive workpieces and thin-walled parts made of titanium alloy, was performed experiencing various combinations of feed to the milling cutter tooth, cutting speed and milling cutter teeth space. When machining a thin-walled workpiece, due to less intense heat removal from the cutting zone into the workpiece, the temperatures in the areas of chip contact with the front surface of the tooth, the back surface of the tooth with the workpiece and the temperature of the workpiece itself are higher than when in a massive workpiece treatment. The patterns of changes in the parameters of the milling process of thin-walled workpieces depending on the feed, cutting speed and the milling cutter teeth space are established. With a larger tool stepover, the average and maximum temperatures in the areas of chip contact with the front surface of the tooth and the back surface of the tooth with the workpiece are lower in most of the combinations of mode elements used. Equations that establish the effect of feed on the milling cutter tooth, cutting speed and spacing of teeth on the parameters of the machining are obtained. The results of the study will allow choosing a rational milling mode and spacing of teeth in the work on workpieces of thin-walled parts made of titanium alloy.

The Influence of Different Sustainable Substrates on the Nutritional Value of Tenebrio molitor Larvae

Every year, over 30% of food production is wasted. However, promoting a sustainable food supply not only fosters economic stability in agriculture and the food industry, but also safeguards precious natural resources and ensures universal food access and safety. Therefore, the aim of the study was to determine how specific growth conditions (utilizing by-products: sprouted potatoes (1), wheat bran (2), brewers’ spent grain (3), and a control sample with agar-agar gels (4)) affect the larvae of yellow mealworms (Tenebrio molitor). This includes their nutritional and energy value, consumer sensory profiling, and technological parameters of processing. The results have indicated that larvae reared on the substrate with wheat bran had the highest energy value, at 708.26 kcal. In larvae, the difference in protein content was not significant when changing the rearing conditions, and ranged between 48.54 and 59.18%. The larvae contained a significant content of fibers, with the highest amount detected in samples with brewers’ spent grain. The data indicate that glucose and arabinose were distinctive to larvae. Our study has also revealed a statistical difference in ash content between larvae and the substrate, with higher levels of nitrogen, copper, and zinc detected in the larvae compared to the substrate. We have found that the salt was naturally occurring in the substrates, with the brewers’ spent grain sample having the highest amount, at 1.83%. However, the control sample yielded the highest ratings, achieving a score of 7.30 for general smell acceptability. These findings emphasize the potential of utilizing various industrial and farm by-products as substrates for mealworms, transforming them into a sustainable and nutrient-rich food source. This contribution adds to the broader discourse on nutritional value and resource efficiency.

Laboratory evaluation of a complex treatment technology for reducing water absorption of the pavement subbase aggregate from the blast-furnace slag

When smelting each ton of pig iron, approximately 500 kg of blast-furnace slag is formed and requires recycling. Air-cooled blast-furnace slag can be used for the manufacture of slag aggregate for the pavement subbase layers, as an alternative to natural stone aggregate. The wide use of slag in this area is limited by its high water absorption. This paper proposes a complex technology to reduce water absorption of slag aggregate. This technology includes selective crushing, which allows separating low-porosity aggregate grains from high-porosity ones, and impregnation of selected low-porosity grains with hydrophobic agent (surface hydrophobization). The results of a laboratory evaluation of this technology effectiveness are presented. Article also contains optimal parameters of this complex technological process which allowed to reduce the water absorption of the slag aggregate from 4.54% to 1.05%.

Electronic logbook of measuring instruments as a lean management technology

The competitiveness of a manufacturing company in the market is impossible without monitoring and controlling the parameters of technological processes, equipment operation, the state of the production environment and product quality, which, in turn, is associated with the performance of certain measuring operations. Ensuring the uniformity of measurements and accuracy of measuring equipment is the responsibility of the company’s metrologists. Automatization of their activities is a necessary element of lean and efficient management. Let’s consider its practical advantages on a simple example of digitalization of work on the accounting of measuring instruments.

Analysis of Thermodynamic Events Taking Place during Vacuum Drying of Corn

Agricultural materials (LF products) can be considered biologically living organisms due to their structure and the composition of colloidal capillary-porous substances in them. They contain a large number of microscopic pores, microcapillaries and macrocapillaries, in which water is able to pass from the inner parts to the surface of the grain, and vice versa. Thus, it can be concluded that drying is an important and demanding aspect of agricultural production. To determine the optimal drying process for agricultural cereals from a nutritional, energy, economic and environmental point of view, it is necessary to address in detail the application of the technology of vacuum drying from a thermodynamic point of view. An analysis of the research results shows that drying temperature, harvest date and corn variety can significantly affect the properties of the main components of corn grain. This study investigates the individual technological parameters of the vacuum drying process for corn, such as the pressure used in the drying chamber, the grain drying temperature and the heating time, in order to achieve a maximum reduction in water content. The aim of the investigation is to determine the optimal parameters for the design of a functional prototype of a vacuum dryer. For this purpose, laboratory and semi-operational experiments using different types of organic materials are necessary. The structural design of the individual elements of the vacuum dryer is based on an analysis of laboratory and experimental tests, whose results are presented in this article.