The subject of the study is the external removable means of heat exchange pipes for intensifying the heat exchange process in technological equipment and pipelines of various sectors of the economy. Studies of the state of art and prospects of constructive and technological design of external removable elements of pipes for heat transfer intensification are based on a critical analysis of scientific and technical sources of information and, above all, patent information from the leading countries of the world, since it is in the patent documentation that information is provided on innovative developments in the relevant field of technology and technology. With the help of methods of analysis and synthesis, external removable elements of pipes for the intensification of heat transfer of equipment and pipelines in the chemical and related branches of technology are systematized. For each type of elements, a detailed classification has been developed, on the basis of which the most interesting designs proposed by scientists, designers and inventors of the leading countries of the world are considered. A critical assessment is given to most of the elements, an analysis of their advantages and disadvantages is made. Preference is given to sources of information from the end of the second and beginning of the third millennium. The designs of these elements are analyzed depending on the regime of the fluid coolant, the presence of a change in the state of aggregation of the coolant, the nature of the effect on the flow over time, the nature of the change in the flow hydrodynamics, the degree of change in the flow hydrodynamics, the relative length, the orientation of the pipes in space, the degree of the channel curvature, the material, the degree of assembly , the degree of mobility of the components, the number of covered pipes, as well as the type of blank. It is shown that, despite a significant variety of designs of external removable elements of pipes for heat transfer intensification, metal plate elements tested in manufacture and operation remain the most in demand by the industry. However, due to the advances in materials science and computer modeling, the search for new designs of pipe elements to intensify heat transfer continues.

Предмет дослідження – найбільш поширений вид роз’ємних з’єднань у хімічному, нафтохімічному, нафтопереробному, харчовому та енергетичному машино- та апаратобудуванні, а саме фланцеві з’єднання технологічного й допоміжного обладнання, а також трубопроводів. Дослідження стану питання й тенденцій розвитку конструктивно-технологічного оформлення фланцевих з’єднань ґрунтуються на критичному аналізі науково-технічних джерел інформації й передусім – патентної інформації провідних країн світу, оскільки саме в патентній документації наводяться відомості про інноваційні розробки у відповідній галузі техніки й технології. За допомогою методів аналізу й синтезу систематизовано фланцеві з’єднання, які впливають на ефективність експлуатації обладнання та трубопроводів хімічної і споріднених галузей технології. Для кожного виду пристроїв розроблено ґрунтовну класифікацію, на основі якої докладно розглянуто найбільш цікаві конструкції, запропонованих науковцями, конструкторами й винахідниками провідних країн світу. Надано критичну оцінку більшості наведених конструкцій, обговорено їхні переваги й недоліки. Перевагу надано джерелам інформації кінця другого та початку третього тисячоліття. Конструкції фланцевих з’єднань проаналізовано залежно від ступеня складання, ступеня рухливості їхніх конструктивних елементів, можливості зняття фланців без демонтажу всього з’єднання, механізму стискання ущільнювальної прокладки, наявності додаткових функцій, а також матеріалу фланців. Показано, що, незважаючи на значну різноманітність розроблених конструкцій фланцевих з’єднань, найбільш затребуваними промисловістю залишаються апробовані у виготовленні та експлуатації плоскі приварні та приварні встик фланці, а також вільні фланці на приварному кільці. Проте завдяки успіхам матеріалознавства та комп’ютерного моделювання пошуки нових конструкцій фланцевих з’єднань продовжуються.

The article presents the results of theoretical and experimental studies of specific contact electrical resistance (SCER) and specific electrical resistance (SER) of electrical contact gaskets (ECG) made of thermally expanded graphite (TEG) and intended for their placement on the ends of electrode blanks before their graphitization in direct heating furnaces – furnaces Castner's. The obtained data of SCER “graphite–gasket–graphite” and SER (or electrical conductivity) of the ECG material are needed to minimize the energy consumption of the graphitization process using numerical modeling of the thermoelectric state of Castner's furnaces in order to develop energy-efficient regulations for their operation. The method of two samples was used for the experimental determination of the SCER, and the theoretical-experimental approach was used for the study of the SER, which makes it possible to exclude the influence of the contact resistance between the experimental sample and the electrodes for supplying the electric current on the value of the measured quantity and is based on the solution of the inverse coefficient problem of electrical conductivity (ICPE) using experimental data obtained during the SCER study. A mathematical formulation of the ICPE was formulated, a numerical method and an algorithm for its solution were developed, and a study of the SER of the TEG at different values of temperature and pressure was carried out. Determination of SCER and SER was carried out for ECG material with an initial density of 1000 kg/m3 in the temperature range up to 250 °С under different pressures in the range of up to 1.75 MPa. The results of these studies are presented in the form of two-parameter dependences on pressure and temperature with extrapolation up to 3000 °C. The measurement error of SCER and SER by the specified methods is estimated to be within 4–5% in the intervals of temperature change up to 250 °С and pressure up to 1.75 MPa. The obtained SCER and SER dependences for the ECG material are needed to perform a numerical analysis of the thermoelectric state of Castner's furnaces in order to develop rational graphitization regulations.

The generalized mathematical model of physical fields, which describes the main technological divisions of producing electrode carbon-graphite products, has been refined in terms of considering the equation of the state of the loose medium and the turbulence of the flows of the working medium. Based on the generalized model, approaches to formulating mathematical models of such individual redistributions of electrode production as calcination of carbon-containing filler, pressing, firing, and graphitization of electrode blanks are shown. Using numerical modeling, resource- and energy-efficient technological regulations for the calcination of carbon-containing fillers in electrocalciners and firing of graphite products in a Riedhammer ring multi-chamber furnace were developed. It was established that the developed regulations for the start-up and operation of the electrocalciner for heat treatment of anthracite ensure the required quality of the final product and long-term operation of the equipment - more than 6 months. It is shown that the developed technological regulations for firing various graphite products in Riedhammer furnaces provide a 7–10

The subject of the research is the most common type of detachable joints in chemical, petrochemical, oil refining, food and energy machine and apparatus construction, namely flanged joints of technological and auxiliary equipment, as well as pipelines. The study of the state of the issue and trends in the development of structural and technological design of flanged joints is based on a critical analysis of scientific and technical sources of information and, above all, patent information of the leading countries of the world, since it is in the patent documentation that information is given about innovative developments in the relevant field of engineering and technology. With the help of methods of analysis and synthesis, flange connections that affect the efficiency of operation of equipment and pipelines in the chemical and related fields of technology have been systematized. A thorough classification has been developed for each type of device, based on which the most interesting designs proposed by scientists, designers and inventors of the world's leading countries have been examined in detail. A critical assessment of most of the above constructions is provided, their advantages and disadvantages are discussed. Preference is given to sources of information from the end of the second and beginning of the third millennium. The constructions of flanged joints were analyzed depending on the degree of assembly, the degree of mobility of their structural elements, the possibility of removing the flanges without dismantling the entire joint, the mechanism of compression of the sealing gasket, the presence of additional functions, as well as the material of the flanges. It is shown that, despite the considerable variety of developed designs of flanged connections, the most demanded by the industry are flat welded and butt-welded flanges, as well as free flanges on a welded ring. However, thanks to the advances in materials science and computer modelling, the search for new flange connection designs continues. The developed detailed classification of flange connections can be useful to the developers of new equipment for the creation of highly efficient technological equipment of various industries.

У статті наведено результати теоретико-експериментальних досліджень електричних властивостей електроконтактних прокладок, призначених для їх розміщення по торцях електродних заготовок перед їх графітуванням у печах прямого нагрівання (печах Кастнера). Проведено дослідження питомого контактного електричного опору «графіт–прокладка–графіт», за результатами якого отримано двопараметричну залежність від тиску й температури, яка потрібна для виконання розрахунків теплоелектричного стану печі Кастнера з метою розробки раціональних регламентів графітування. При цьому між електродними заготовками в керні (сукупності послідовно складених для графітування електродних заготовок з електроконтактними прокладками між ними) можна використовувати формулювання контактної теплоелектричної задачі без врахування фізичних розмірів електроконтактних прокладок. Також сформульовано математичну постановку оберненої коефіцієнтної задачі електропровідності, розроблено числову методику й алгоритм розв’язання задачі та проведено з використанням експериментальних даних теоретичні дослідження питомого електричного опору матеріалу прокладок з терморозширеного графіту за різних значень температури й тиску.

Предмет дослідження – зовнішні знімні засоби теплообмінних труб для інтенсифікації процесу теплообміну в технологічному обладнанні та трубопроводах різних галузей економіки. Дослідження стану питання й тенденцій розвитку конструктивно-технологічного оформлення зовнішніх знімних елементів труб для інтенсифікації теплообміну ґрунтуються на критичному аналізі науково-технічних джерел інформації й передусім – патентної інформації провідних країн світу, оскільки саме в патентній документації наводяться відомості про інноваційні розробки у відповідній галузі техніки й технології. За допомогою методів аналізу й синтезу систематизовано зовнішні знімні елементи труб для інтенсифікації теплообміну обладнання та трубопроводів хімічної і споріднених галузей технології. Для кожного виду елементів розроблено ґрунтовну класифікацію, на основі якої докладно розглянуто найбільш цікаві конструкції, запропоновані науковцями, конструкторами й винахідниками провідних країн світу. Надано критичну оцінку більшості наведених конструкцій, обговорено їхні переваги й недоліки. Перевагу надано джерелам інформації кінця другого й початку третього тисячоліття. Конструкції зазначених елементів проаналізовано залежно від режиму руху текучого теплоносія, наявності зміни агрегатного стану теплоносія, характеру дії на потік у часі, характеру зміни гідродинаміки потоку, ступеня зміни гідродинаміки потоку, відносної довжини, орієнтації труб у просторі, ступеня кривизни каналу, матеріалу, ступеня складання, ступеня рухливості складових частин, кількості охоплюваних елементами труб, а також типу заготованки. Показано, що, незважаючи на значну різноманітність конструкцій зовнішніх знімних елементів труб для інтенсифікації теплообміну, найбільш затребуваними промисловістю залишаються апробовані у виготовленні та експлуатації металеві пластинчасті елементи. Проте завдяки успіхам матеріалознавства та комп’ютерного моделювання пошуки нових конструкцій елементів труб для інтенсифікації теплообміну тривають.

Розроблено класифікацію подрібнювальних тіл барабанних подрібнювачів – млинів і дробарок – для руйнування кускових і сипких матеріалів, оброблюваних на підприємствах хімічної, гірничорудної, будівельної, харчової, металургійної та електродної галузей промисловості. Виконано критичний огляд найбільш характерних конструкцій подрібнювальних тіл барабанних подрібнювачів, запропонованих науковцями, конструкторами й винахідниками провідних країн світу. Конструкції подрібнювальних тіл проаналізовано залежно від методу подрібнювання, їхньої форми, ступеня складання, ступеня рухливості елементів тіл, наявності додаткових функцій, а також матеріалу тіл та їхніх конструктивних елементів.

Розроблено класифікацію валкових дробарок і млинів для руйнування кускових і сипких матеріалів, оброблюваних на підприємствах хімічної, гірничорудної, будівельної, харчової та електродної галузей промисловості, а також у металургії. Виконано критичний огляд найбільш характерних конструкцій валкових дробарок і млинів, запропонованих науковцями, конструкторами й винахідниками провідних країн світу. Конструкції проаналізовано залежно від кількості валків, типу поверхні валків, форми валків, відносної швидкості робочої поверхні валків, можливості регулювання температури поверхні валків, наявності додаткових робочих органів, а також матеріалу поверхні валків.

The classification of roll crushers and mills for the disintegration of lumpy and loose materials processed at the enterprises of chemical, mining, construction, food and electrode industries, as well as in metallurgy, has been developed. A critical review of the most typical designs of roll crushers and mills proposed by scientists, designers and inventors of the world’s leading countries has been performed. The designs are analyzed according to the number of rolls, type of roll surface, shape of rolls, relative speed of working surface of rolls, possibility of roll surface temperature control, availability of additional working elements, as well as roll surface material. Analysis of the designs of roll crushers and mills for the disintegration of lumpy and granular materials shows that they exist in numerous standard sizes, but conventional two-roll crushers with smooth, fluted and toothed rolls remain the most demanded by industry. In this case, the most promising area for improvement of roll crushers and mills is to develop designs of crushing elements for the working surface of rolls and materials for their manufacture. In the future, it is planned to analyze the designs of other types of crushing equipment widespread in industry, such as jaw crushers and drum mills, as well as ways to improve their efficiency.

A classification of heat exchangers with fluidization of bulk material for use in enterprises of the chemical, mining, construction, food, metallurgical and processing industries has been developed. A critical review of the most characteristic designs of heat exchangers with a fluidized bed, proposed by scientists, designers and inventors of the leading countries of the world, has been carried out. The designs of heat exchangers are analyzed depending on the method of fluidization, the role of bulk material in the heat exchange process, the nature of the heat exchange process over time, the nature of fluidization (in continuous heat exchangers), the mechanism of heat exchange of bulk material, the number of fluidized beds, the presence of additional heat exchange devices in the heat exchanger, the presence of movable structural elements, as well as the type of bulk material of the fluidized bed. An analysis of the designs of heat exchangers with a fluidized bed indicates their considerable diversity, however, the most simple to manufacture and operate reliable devices with fixed structural elements and one fluidized bed remain in demand by the industry. The most promising direction for improving fluidized bed heat exchangers is the development of specialized (for processing bulk material or fluid coolant) designs of apparatuses. In the future, it is planned to analyze the designs of other types of heat exchangers, as well as ways to improve their efficiency.

A classification of grinding bodies of drum grinders – mills and crushers – for the destruction of lumpy and bulk materials processed at enterprises of the chemical, mining, construction, food, metallurgical and electrode industries has been developed. A critical review of the most characteristic designs of grinding bodies of drum mills proposed by scientists, designers and inventors of the leading countries of the world has been carried out. The designs of grinding bodies are analyzed depending on the method of grinding, shape, degree of assembly, degree of mobility of the bodies elements, the presence of additional functions, as well as the material of the bodies and their structural elements. An analysis of the designs of grinding bodies of drum mills and crushers for the destruction of lumpy and bulk materials indicates the presence of their significant diversity, however, traditional grinding bodies in the form of balls and cylinders remain the most used in industry. At the same time, the most promising direction for improving the grinding bodies of drum grinders is the development of specialized (rather than traditional universal) designs of grinding bodies, as well as materials for their manufacture.

Production of electrode carbon-graphite products is one of the most energy-intensive chemical and metallurgical industries. One of the ways to reduce the energy intensity of electrode carbon-graphite products is to improve the energy efficiency of the furnace equipment of its main processes. A mathematical model of the combustion process of synthesis gas and natural gas in the working space of a rotary kiln was formulated. Two numerical models were developed. The first one is to study the heat-hydrodynamic state of a rotary kiln during natural or synthetic gas. The second one is to study the thermal parameters of a rotary kiln during the combustion of synthesis gas together with natural gas. Calculations were carried out to determine the synthesis gas consumption as a substitute for natural gas. It was established that at the expense of partial or complete replacement of natural gas by synthesis gas during operation of a calcining rotary kiln, it is possible to decrease natural gas consumption up to 100

The necessity of development of technical solutions that will allow to reduce carbon monoxide emissions of flue gases of industrial productions is substantiated. It is shown that the most rational design solution to the problem of carbon monoxide pollution during the firing of electrode blanks is the use of aerated concrete blocks with a catalyst, which can be quickly and conveniently located directly on the carbon material of the "green" electrodes pouring in the subfloor space of the firing furnaces. Modified by oxides of Mn4+, Fe2+, Fe3+, Cu2+, Cr3+-catalysts based on aerated concrete were obtained. It is shown that in an empty reactor in the temperature range 200-400 degrees C the degree of conversion of carbon monoxide in the absence of a catalyst is zero. It is established that on the investigated catalysts based on aerated concrete 100% oxidation of carbon monoxide is achieved at a temperature of 390 degrees C in the case of using a mixture of catalyst powders 30% CuO + 70% MnO2, 40% CuO + 60% MnO2, 50% Fe (FexCr(1-x)) 2O4 + 50% MnO2; 50% Fe3O4 + 50 % MnO2. It is determined that the addition of ferrite catalyst powder in aerated concrete in a mixture or without manganese dioxide does not critically affect the mechanical properties of the products.

Проаналізовано існуючі математичні моделі,використовувані для аналізу процесу газифікації твердого палива з метою зниження витрати природного газу в енергетичній та інших енергоємних галузях промисловості, а також зниження шкідливого впливу на довкілля за рахунок застосування синтез-газу, одержуваного в результаті газифікації. Незважаючи на значний світовий досвід у галузі моделювання процесу термічного перероблення палива на горючий газ, натепер відсутня модель, яку можна було би застосувати безпосередньо на практиці. Тому питання розроблення адекватної математичної моделі процесу одержання й використання синтез-газу на основі реакції газифікації вуглецю залишається вкрай актуальним завданням.

Проаналізовано особливості конструкцій, складу і властивості електроконтактних з’єднань між заготовками в колонах керна печей Кастнера для графітування електродів. Показано, що від якості контакту між заготовками суттєво залежать експлуатаційні властивості одержуваної продукції. Тому розробка таких з’єднань разом з відповідними енергоефективними регламентами графітування електродних заготовок з електроконтактними прокладками певного типорозміру є актуальним і вкрай важливим завданням електродної галузі.

Significant fluctuations in the price of natural gas are the reason for the transition of the energy and energy-intensive industries to increase the use of solid fuels with their preliminary gasification, that is, the residual conversion of the organic part of solid or liquid fuels to combustible gas by its interaction at high temperature (1000–2000 °C) with air, water vapor, industrial oxygen and carbon dioxide, as well as mixtures thereof. The gasification process is carried out in gas generators, so the resulting gas is called generator gas.Analysis of studies of the production of synthetic gas from coal and biomass, its use to generate heat and electricity shows that the raw materials for the process of gasification of fuel are usually coal and brown coal, oil shale, peat, wood, fuel oil, tar; reactions occurring during gasification of solid fuels include the following heterogeneous and homogeneous reactions: oxidation of semicoke, gasification of CO2, H2O and H2, direct and reverse water vapor reactions, methane formation, methane decomposition with hydrogen reduction, etc .; gasifiers of three main types are used in industry, which differ in the nature of the interaction of solid fuel with blast: in the stream, with a fixed or moving bed, with a fluidized bed.The most powerful gas generators are gasifiers with gasification in the stream (up to 1000 MW); gasification technology is developing rapidly in the world and there are many examples of commercial-successful implementation of projects designed to generate electricity and heat, in particular: Nexterra Systems Corp., Vancouver, Brіtіsh Columbіa, Canada with a capacity of 2–10 MW, efficiency of thermal power station up to 60 %, gasifier – fixed bed with upward flow; a bubble fluidized gasifier at a power plant in Värnamo, Sweden with an electric capacity of 6 MW and a thermal capacity of 9 MW; Siemens gasifier at a power station in Freberg, Germany works on brown coal, operating pressure 30 bar and temperature 1400 °C, electric power 5 MW, etc.In the future, it is planned to develop technical solutions for the partial replacement of natural gas with synthetic gas in the technological process for the high-temperature processing of carbon-containing bulk materials in rotary kilns using the heat of the material leaving the furnace to ensure the temperature conditions of the gasification process. It is also planned to analyze existing mathematical models of the process of carbon-containing raw materials gasification in order to determine their applicability for the analysis of the gasification process.

One of the main factors influencing the quality of electrode products is the electrical contact connections between the blanks in the core columns of direct heating furnaces (Castner furnaces), which produce high-quality graphite electrodes for metallurgy. It is known that electrical contact connections between electrode blanks significantly affect the quality of the obtained electrode products. Given that Castner furnaces are now the main type of furnaces in the electrode industry in the world, the increase in the efficiency of these furnaces can to some extent be attributed to solving the problem of both domestic and global levels.One of the ways to increase the efficiency of Castner furnaces is to develop high-quality electrical contacts together with the appropriate energy-efficient regulations for graphitization of electrode blanks, which is certainly an important and extremely important task of the electrode industry.The aim of the article is the analysis of constructive-technological methods (first of all electrical contact gaskets) of assembling columns of electrode blanks for their graphitization in direct heating furnaces and their influence on the qualitative characteristics of the obtained electrode products.As a result of the analysis of researches of a modern condition of a problem of assembly of columns of preparations of electrodes for their graphitization in furnaces of direct heating it is shown that:– the decisive structural and technological factor of the process of graphitization of electrode blanks in direct heating furnaces are contact gaskets, which are a component of the columns of electrode blanks and are located between the ends of adjacent blanks;– the process of graphitization of electrode blanks in direct heating furnaces depends on such parameters of electrical contact gaskets as gasket material, in particular its structure, density and electrical resistivity, as well as the shape and size of gaskets:– the main direction of improvement of electrical contact gaskets is the development of their composition (qualitative and quantitative), but almost no study of the possibility of creating fundamentally new design solutions, including gaskets and their elements of new shapes and sizes based on structural materials that have proven themselves in industrial production.In the future it is planned to develop a method of manufacturing electrical contact connections and their fixation between electrode blanks, which provide high uniformity of thermoelectric fields in core columns, as well as a method of forming core columns consisting of electrode blanks and electrical contact connections between them, outside Castner furnaces, which allows to significantly reduce the downtime of furnaces between campaigns. It is also planned to develop intensified energy-efficient regulations for the introduction of electric power into the Castner furnace, which ensure the minimization of specific energy consumption of the graphitization process.

A modified MnO2 clinoptillolite was obtained by using the available zeolite rock from the Sokyrnytsia deposit (Khust district of the Zakarpattia region, Ukraine) using a simple technique of mixing solutions containing separately Mn2+ and MnO4-. It was determined that the total manganese content in the air-dry modified thermally untreated clinoptyllolite was 11.42 mg/g, which is 1.8 % in terms of MnO2. Structural characteristics, namely, the pore size distribution and specific surface area as the main basic characteristics of the catalyst, were studied, which were obtained from the isotherms of low-temperature nitrogen adsorption-desorption. These studies are necessary to determine the limiting stage of CO oxidation. It has been determined that the kinetics of the oxidation process is described by a first-order equation. Based on the obtained characteristics of the catalyst, the kinetic parameters of the process were calculated, namely, the effective and true rate constants and the activation energy, which is 31 kJ/mol. It has been proved that the oxidation reaction of carbon monoxide on an oxide-manganese catalyst proceeds in the intra-diffusion mode. This makes it possible, using the criterion dependences, namely, the Carberry criterion, which is less than 0.05, to assert that the reaction is not limited by the diffusion of CO from the gas stream to the outer surface of the catalyst. It is shown that the transport of carbon monoxide molecules inside the catalyst granules proceeds in the Knudsen regime. The obtained scientific result in the form of a kinetic description of the catalytic oxidation of carbon monoxide with atmospheric oxygen on a manganese oxide catalyst based on zeolite is interesting from a theoretical point of view. From a practical point of view, the calculated kinetic parameters of this process make it possible to calculate a catalytic CO oxidation reactor

Tools in the form of methodology and software for the numerical study of the thermal-elastoplastic state of coke-pitch composites using the example of isostatic graphite production technology have been developed. A closed mathematical formulation and a method for numerically solving an elastoplastic problem with isotropic hardening based on an implicit inverse mapping algorithm are considered. Using the finite element method, the corresponding program code was developed and verified. A comparison of the results with the data of numerical analysis obtained using the ANSYS Mechanical APDL software product shows that, with isotropic hardening, the maximum discrepancy does not exceed 1.13%, and for ideal plasticity, it is no more than 3.58%. The calculations of the thermal-elastoplastic behavior of the coke-pitch composite in the technological stage of the production of isostatic graphite blanks are performed. It is shown that in the case of non-compliance with the temperature regimes at the initial stages of roasting, plastic deformations occur in the isostatic graphite blanks, which lead to cracking and deterioration of the uniformity of the physical properties of the finished products.