scholarly journals АЛГОРИТМ ПРОЕКТУВАННЯ АВТОМАТИЗОВАНИХ ЗМІШУВАЛЬНИХ КОМПЛЕКСІВ БЕЗПЕРЕРВНОЇ ДІЇ ДЛЯ СИПКИХ МАТЕРІАЛІВ

2022 ◽  
pp. 18-30
Author(s):  
OLEKSANDR BURMISTENKOV ◽  
TETIANA BILA ◽  
VOLODYMYR STATSENKO
Keyword(s):  
Classical Mechanics ◽  
Physical And Mechanical Properties ◽  
Discrete Elements ◽  
Technological Parameters ◽  
Component Mixture ◽  
Design Algorithm ◽  
Continuous Mixing ◽  
Centrifugal Mixer ◽  
Bulk Motion ◽  
Mixture Homogeneity

Purpose. Creation of design algorithm of continuous action mixing complexes that will allow defining parameters of the equipment proceeding from requirements to quality, productivity and the set compounding of mixture.Methodology. The method of discrete elements, classical mechanics positions, theory of solids contact interaction, method of mathematical modeling are used in the work.Findings. The paper proposes a generalized algorithm for designing a continuous mixing complex for bulk materials. The procedure for designing a centrifugal mixer, the flow shapers, plate feeders and conical-cylindrical hoppers are presented. Calculations of design and technological parameters are carried out on the basis of information about the physical and mechanical properties of bulk components particles, requirements for equipment performance and the mixture homogeneity. The results of calculations of the mixing complex for the three-component mixture used for the production of polyethylene film are presented. To test the proposed algorithm, a mathematical model based on the discrete elements method is created. The mixing process is modeled and the coefficients of inhomogeneity of each of the components in the finished mixture are determined. The obtained results confirmed that the proposed algorithm allows to determine the parameters of the mixing complex, which ensure compliance with the specified requirements for the quality and the equipment performance.Originality. Mathematical models of bulk motion dynamics in mixing complexes are improved, which include bunker devices, plate feeders, flow shapers and continuous centrifugal mixer, taking into account the bulk motion discrete nature.Practical value. The obtained results allow calculating the design and technological parameters of the equipment that is a part of the continuous mixing complex according to the set productivity, recipe and requirements to the mixture homogeneity.

scholarly journals ANALYSIS OF EXTERNAL ENGINEERING NETWORK METHODS

2020 ◽  
Vol 4 (157) ◽  
pp. 7-11
Author(s):  
V. Zhvan ◽  
V. Donenko ◽  
S. Kulish ◽  
A. Taran
Keyword(s):  
Physical And Mechanical Properties ◽  
Directional Drilling ◽  
Horizontal Directional Drilling ◽  
Technological Parameters ◽  
Optimal Method ◽  
Advantages And Disadvantages ◽  
Analytical Review ◽  
Conducting Research ◽  
The Cost ◽  
Selection Of

The article is devoted to the effective analysis of trench and trenchless pipeline laying technologies. In the course of the work, an analytical review of pipeline assembly was performed, the main technological parameters, the scope of each method, and their advantages and disadvantages were determined. List of considered pipeline laying methods: trenching, horizontal directional drilling, mechanical puncture, hydraulic puncture, microtunneling and punching. The article analyzes the classical trench method and the most widely used trenchless ones: horizontal directional drilling; mechanical puncture; hydraulic puncture; microtunneling; punching. Each of these methods has several advantages and disadvantages. The choice of the optimal method of laying the pipeline depends on many factors: the physical and mechanical properties of soils and hydrogeological conditions, the length and diameter of the pipeline, the presence of other communications, buildings and structures, as well as the budget that customers have. Work time is the last deciding factor. Based on the results of the analysis of pipeline laying technologies and expert survey of construction industry experts, the cost table of each method was compiled, outlining the main characteristics of the technology: length of pipeline, speed of work, scope, cost, and the advantages and disadvantages of each of the considered methods. The conclusions about the use of each of the pipeline laying methods were made. Each of the methods has its advantages and disadvantages, so to choose the method of work it is necessary to conduct a comprehensive assessment of technological parameters, cost, scope and timing of work. The cost of lay-ing the pipeline consists of the following factors: conducting research; selection of diameter and determination of pipeline length; choice of laying method and equipment necessary for the works; selection of equipment, shut-off and control equipment and other materials arranged on the pipeline; terms of performance of works. Taking into account these factors, an estimate is made, which determines the cost of installation of a particular pipeline. After the analysis, we can conclude that among the methods of trenchless laying of pipelines can be identi-fied horizontally directional drilling, it is this method of laying the pipeline will be appropriate to use for our region. The drilling technique allows to carry out pipelines under obstacles, to pull long segments of networks, to repair site damage. This method is universal and can be used in almost any environment. Keywords: trenches, horizontal directional drilling, mechanical puncture, hydraulic piercing, microtunnelling, punching, pipeline.

scholarly journals RESEARCH OF PHYSICAL AND MECHANICAL PROPERTIES OF WOOD-FIBER MATERIALS

2020 ◽  
pp. 451-457
Author(s):  
Aleksandr Yur'yevich Vititnev ◽  
Yuriy Davydovich Alashkevich ◽  
Natal'ya Geral'dovna Chistova ◽  
Roman Aleksandrovich Marchenko ◽  
Venera Nurullovna Matygullina
Keyword(s):  
Mechanical Properties ◽  
Wood Fiber ◽  
Experimental Studies ◽  
Physical And Mechanical Properties ◽  
Production Method ◽  
Strength Properties ◽  
Grinding Process ◽  
Technological Parameters ◽  
Fiber Materials ◽  
Traditional Construction

This paper presents the results of experimental studies of the physical and mechanical properties of wood-fiber boards of the wet production method when regulating the design and technological parameters of the grinding process. This allowed us to determine the influence of the working clearance between the grinding discs and the concentration of fibre mass with the subject to of quality change wood fiber after defibrator using the developed construction of the disc fibrillation action on the physico-mechanical properties of boards. As a result of the experiment, regression models were obtained that adequately describe the studied grinding process and allow predicting the values of physical and mechanical properties of the finished product depending on the established  parameters process. A comparative analysis of the size and quality characteristics of the fiber semi-finished product and its fractional composition when using a developed construction the disc of refiner fibrillation action and a traditional design used in industry is carried out. The preferential efficiency of the grinding process under the fibrillating effect the disc of refiner in comparison with the traditional construction disc of refiner is established. As a result, there is a significant improvement in the quality indicators of the fiber semi-finished product and its composition due to the formation and predominance in the total mass of long and thin, respectively, flexible fibrillated fibers with high tile-forming properties, which allows to increase the strength properties of the product (by 20–25%), without using binding resins.

scholarly journals METHOD OF SAMPLE MANUFACTURING FROM MULTILAYER COMPOSITE MATERIALS FOR STUDYING THEIR MECHANICAL PROPERTIES

2018 ◽  
pp. 16-23
Author(s):  
Alsaid Mazen ◽  
Ali Salamekh
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Polymer Composite ◽  
Testing Machine ◽  
Physical And Mechanical Properties ◽  
Polymer Composite Materials ◽  
Technological Parameters ◽  
Cutting Out ◽  
Method Of Production ◽  
Economic Considerations

In the last decades there is increasing the need to apply polymer composite materials in different industries, particularly in shipbuilding. There are developing single structures made from polymer composite materials to be used on board ships. The article focuses on technology of manufacturing slabs from polymer composite materials to carry out mechanical testing in the laboratory special standard units. Mechanical properties of polymer composite materials depend on molding technologies. There has been described a technology of sample manufacturing from polymer composite materials reinforced with glass fiber mat with fiberglass plastics. The technique of testing the specified samples for tensile strength has been considered. The sizes and shapes of the samples as well as the technological parameters of the manufacturing process have been validated, depending on the standard requirements and the technological features of the testing machine. The physical and mechanical properties of the components that make up the composite materials are considered. The sequence of stacking layers for preparation of plates from composite materials is indicated. The dimensions of the plates for cutting out finished samples are determined, depending on the method of production. The way of laying plates from composite materials has been chosen on the base of economic considerations and conditions of accessibility. The obtained results of mechanical properties can be used in solving problems of application of polymer composite materials in shipbuilding, for example, in manufacturing superstructures of some dry cargo vessels.

Two-step validation process of particle mixing in a centrifugal mixer with vertical axis

2016 ◽  
Vol 232 (1) ◽  
pp. 29-37
Author(s):  
Matej Zadravec ◽  
Blaž Orešnik ◽  
Matjaž Hriberšek ◽  
Jure Marn
Keyword(s):  
Numerical Simulation ◽  
Friction Coefficient ◽  
Numerical Simulations ◽  
Static Friction ◽  
Vertical Axis ◽  
Rolling Friction ◽  
Angle Of Repose ◽  
Discrete Elements ◽  
Power Characteristics ◽  
Centrifugal Mixer

Two-step approach of validation is proposed to validate a numerical model, capable of accurate prediction of mixing power characteristics of a centrifugal mixer with vertical axis. Two sets of experiments and two sets of numerical simulations are presented—the first set to determine physical characteristics of the particles comparing the numerical simulations results with experimental data, and the second set to validate predicted behavior of anchor type vertical axis impeller for mixing of same particles. Zeolite particles were used for actual calculations. After determining shear modulus, coefficient of interaction, static friction coefficient, and rolling friction coefficient through optimization process based on numerical simulations with subject function of diameter and angle of repose derived from experiment, using these values in numerical simulation of impeller mixer mixing zeolite particles led to results, which were in good agreement with results of the second set of experiments. The obtained zeolite material parameter values can therefore serve as a solid basis for discrete elements method based numerical simulation of zeolite granular materials.

scholarly journals Coefficient of local loss of mechanical energy of the flow for a ­mixture of charge materials

2021 ◽  
pp. 26-31
Author(s):  
A Selegej ◽  
V Ivaschenko ◽  
V Golovko ◽  
R Kiriya ◽  
L Kvasova
Keyword(s):  
Comparative Analysis ◽  
Mechanical Energy ◽  
Charge Material ◽  
Equivalent Diameter ◽  
Blast Furnaces ◽  
Technological Parameters ◽  
Component Mixture ◽  
Charge Materials ◽  
Local Loss ◽  
Two Component

Purpose. To determine the dependence of the coefficient of local losses of mechanical energy of flow of a two-component mixture of charge material on its depth, content of components, and average equivalent diameter of particles in the case of their free-dispersed motion. Methodology. The value of the coefficient of local losses of mechanical energy was determined by the value of the hydraulic resistance of the fluid during its movement in open channels and pipes. In this paper, methods were used of comparative analysis, mathematical modeling and forecasting of dynamic processes in the flow of granular material. Findings. Based on the results of theoretical studies, a mathematical model was obtained, the use of which allows calculating the coefficient of local losses of mechanical energy for the flow of a two-component mixture of charge materials with agglomerate particle sizes from 15 to 50 mm, pellets from 6 to 12 mm, coke from 10 to 60 mm. The developed model with satisfactory accuracy makes it possible to evaluate the movement of the charge from the indicated materials along the paths of the charging devices of blast furnaces at a speed in the range from 1.5 to 20 m/s and to determine the trajectories of the mixture of charge materials on the top with an accuracy of 0.2 m. It is noted that the calculation of the above coefficient by the known techniques is not accurate enough, which is associated with the uncertainty in the choice of a single average equivalent diameter of the particles of the two-component charge. Comparative analysis of the developed model with the known models and experimental data indicates that the accuracy of calculating the dynamic parameters of a two-component flow of charge materials using the developed model increases by 510% in comparison with calculations using the previously known models. Originality. For the first time, regularities of changes in the coefficient of internal mechanical losses of a two-component flow of charge materials from its depth, content of components, average equivalent particle diameters when moving along the paths of charging devices of blast furnaces have been established. Practical value. Mathematical dependencies have been developed and can be used to determine the technological parameters of the charge of a modern blast furnace with different characteristics of the granulometry of the charge and the ratios of its components. This will increase the accuracy of predicting the course of the process under consideration, the degree of automation of the control systems for the technological process of the charge supply of blast furnaces, will make it possible to use expensive charge materials more efficiently, reduce energy consumption and reduce the harmful impact on the environment.

scholarly journals RADIATION RESISTANT BINDING MATERIALS BASED ON SILICATE ALUMOBARIUM CEMENTS

2020 ◽  
Vol 1 (154) ◽  
pp. 67-70
Author(s):  
N. Tsapko
Keyword(s):  
Physical And Mechanical Properties ◽  
High Strength ◽  
Technological Parameters ◽  
Protective Properties ◽  
Initial Strength ◽  
Radiation Resistant ◽  
Biological Protection ◽  
Effects Of Radiation ◽  
Main Components ◽  
High Degree

The article analyzes the possibility of developing custom binders with a set of set properties. Particular attention is paid to the development of radiation-resistant barium-containing cements based on aluminates and barium silicates. In order to normalize the radiation situation in Ukraine, it is urgent to develop structural materials with specified high protective properties against the effects of radiation, a high degree of biological protection in combination with high strength and fire resistance. The main components of the technological parameters of synthesis of the presented cements are determined. Test results of physical and mechanical properties of refractory radiation resistant cements are presented and general recommendations on the scope of the developed binder materials are given. It is determined that the resulting refractory cement can be used as a bond in the manufacture of special concretes and materials that have high protective properties while exposed to high temperatures and radiation. Thermal stability of concrete based on silicate alumobarium cement with different fillers was determined (cooling of the samples was carried out in air). As a result of the tests, it was found that all concrete specimens withstood more than 20 cycles (1000 ° C - air), while maintaining more than 80 % of the initial strength. These results confirm the known pattern: the higher the material density, the greater the material's ability to absorb radiation. Thus, the obtained data allow us to conclude that concrete based on silicate alumobarium cement have high absorption rates of brake radiation, which is more than 1.5 times higher than currently used concrete based on Portland cement. Therefore, it can be concluded that the concretes obtained are radiation resistant, with a high degree of attenuation of gamma rays and can be recommended as protective materials. Keywords: cement, composition, synthesis parameters, radiation resistance, property, strength

scholarly journals INVESTIGATION INTO TECHNOLOGICAL PARAMETERS OF BITUMEN BATCHING IN AN ASPHALT MIXING PLANT

2015 ◽  
Vol 21 (7) ◽  
pp. 958-965 ◽  
Author(s):  
Justas Bražiūnas
Keyword(s):  
Physical And Mechanical Properties ◽  
Void Content ◽  
Technological Parameters ◽  
Technological Processes ◽  
Road Pavement ◽  
Bitumen Content ◽  
Air Void ◽  
Production Conditions ◽  
Mineral Aggregates

An appropriate bitumen content and its properties in hot mix asphalt (HMA) mixture impact on the long-term mechanical strength of the laid asphalt pavement and the required road operation properties. During the production of a HMA mixture in an asphalt mixing plant (AMP), relationships between the structure and interaction of the mixture are established based on technological processes that specify bitumen batching and component mixing. These processes ensure the long-term strength, texture, evenness, the degree of damage and rheological properties of road pavement. The presented mathematical model enables us to determine the distribution of oxygen pressure by time in differently sized drops of bitumen during their fall into a mixer. The model considers oxygen diffusion, which depends on temperature, and heat conductivity, which depends on temperature, density and specific heat. An active experimental investigation under real production conditions demonstrated that the method of bitumen discharge from a batcher, temperature and time spent mixing materials with hot mineral aggregates impact on properties of bitumen binder within the produced HMA mixture. Parameters of technological processes for mixing of bitumen with mineral aggregates that occur in a bitumen batching system (BBS) are stochastic and impact on the composition of bitumen binder as well as physical and mechanical properties of the produced HMA mixture, namely, air void content, stability, flow and Marshall quotient.

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