Theoretical Foundations of Chemical Engineering最新文献

{"title":"The Electrodynamic Separation of Conducting Materials Using Inductors with a Variable Pole Pair Number","authors":"Yu. V. Afanas’ev,&nbsp;A. Yu. Demin,&nbsp;D. Yu. Pashali,&nbsp;O. A. Yushkova,&nbsp;A. I. Shaikhlislamov","doi":"10.1134/S0040579524601900","DOIUrl":"10.1134/S0040579524601900","url":null,"abstract":"<p>Systems for the automatic sorting of solid household waste and their disadvantages are analyzed. The work considers an original method for the electrodynamic separation of electrically conductive materials with the use of one or more inductors with a variable number of pole pairs to generate a traveling electromagnetic field that affects electrically conductive fragments (ECFs) of solid household wastes (SHW). In the course of separation, the inductor windings are switched in such a way that the pole division discretely changes from the maximum value to the minimum one, or vice versa, within a certain switching time range determined by the maximum inertia of electrically conductive fragments having a size close to the pole division value. The method for electrodynamic separation, as well as the control unit for the electrodynamic separation system, are described. The proposed method should make it possible to extend the functionality of automatic systems for sorting and processing electrically conductive solid household waste and may provide an increase in separation productivity.</p>","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 4","pages":"1218 - 1222"},"PeriodicalIF":0.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143638626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct Numerical Simulation of Turbulent Thermal Diffusivity","authors":"Yu. G. Chesnokov","doi":"10.1134/S0040579525600226","DOIUrl":"10.1134/S0040579525600226","url":null,"abstract":"<p>The influence of the Reynolds and Prandtl numbers on the turbulent thermal diffusivity in a flat channel was studied. The data obtained by various research groups by direct numerical simulation were used. It was shown that the ratio of the turbulent thermal diffusivity to the molecular thermal diffusivity and to the Reynolds number calculated from the dynamic velocity is not a universal function of the dimensionless distance to the wall, as follows from the logarithmic formula for the temperature profile and the temperature defect law, but depends on the Reynolds and Prandtl numbers. Relationships were obtained that allow one to estimate this value at relatively large values of these parameters.</p>","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 4","pages":"1105 - 1111"},"PeriodicalIF":0.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143638621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On Simulation of Thermal Perturbations Introduced into a Rarefied Plasma by Stationary Canonical Bodies","authors":"V. V. Cherepanov","doi":"10.1134/S0040579525600597","DOIUrl":"10.1134/S0040579525600597","url":null,"abstract":"<p>A mathematical model is presented that describes the process of self-consistent relaxation of the disturbance region induced in a free-molecular binary ionized gas by a charged body with an absorbing gas particle surface, which takes on the canonical shape of a sphere or cylinder in thermal problems. The model allows the description and analysis of the thermal field in the vicinity of the body and the thermal loads on its surface. A distinctive feature of such problems is their kinetic formulation, in which it is impossible to separate the processes of heat and mass transfer from the process of electromagnetic field formation. An optimal curvilinear system of nonholonomic coordinates has been chosen for the problem; minimizing the phase space in which the form of the Vlasov kinetic equation has been justified.</p>","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 4","pages":"1343 - 1349"},"PeriodicalIF":0.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143638334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Theoretical Substantiation of Concentration Polarization in Electrochemical Baromembrane Processes for the Purification of Copper-Containing Solutions from Galvanic Plants","authors":"K. V. Shestakov,&nbsp;S. I. Lazarev,&nbsp;M. S. Gessen,&nbsp;D. S. Lazarev,&nbsp;N. N. Ignatov","doi":"10.1134/S0040579525600123","DOIUrl":"10.1134/S0040579525600123","url":null,"abstract":"<p>In this paper, a method of optimizing two functions at once, such as maximum specific solvent flux (water permeability) <i>J</i>_{<i>v</i> max} and minimum concentration polarization θ_min by using a complex criterion Ф and criterial functional restrictions is proposed to determine <i>J</i>_{<i>v</i> max} and θ_min depending on the application of electrical current and the hydraulic permeability coefficients of a solvent. The equations of optimizing the functions of specific solvent flux <i>J</i>_<i>v</i> and concentration polarization θ are given in an analytical form without empirical correction coefficients to simplify the process of optimization. The maximum deviations between the analytically and experimentally found values are less than 3% for <i>J</i>_<i>v</i> and 2% for θ_min.</p>","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 4","pages":"1007 - 1016"},"PeriodicalIF":0.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143638428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of Pump Stations for Contaminated and Aggressive Liquid Media Based on Digital Information Models","authors":"A. I. Repnikov,&nbsp;A. A. Yakovlev,&nbsp;M. P. Kukhtik","doi":"10.1134/S004057952460195X","DOIUrl":"10.1134/S004057952460195X","url":null,"abstract":"<p>An informational description of a pump station for contaminated and aggressive liquid media is given. The stages of design of stations using a digital information model and a scheme for using the model in design are presented. An algorithm for designing pump stations for contaminated and aggressive liquid media is developed.</p>","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 4","pages":"1307 - 1310"},"PeriodicalIF":0.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143638279","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultrasonic Liquid Extraction Using Advanced Cavitation in the Process of Disposal of Spent Lithium-Ion Batteries","authors":"O. M. Gradov,&nbsp;I. V. Zinov’eva,&nbsp;Yu. A. Zakhodyaeva,&nbsp;A. A. Voshkin","doi":"10.1134/S0040579525600329","DOIUrl":"10.1134/S0040579525600329","url":null,"abstract":"<p>The ultrasonic cavitation extraction scheme uses dissolution of waste material in deep eutectic solvent to remove it from the substrate and then extract the valuable element with help of the ultrasonic liquid membrane method. A detailed description of this method is given for the case of using high-power ultrasound under typical conditions of cavitation caused by standing ultrasonic waves when its threshold is significantly exceeded and the extraction process is determined by cavitation parameters and limitations. An expression is obtained for the behavior over time of the amount of the extracted element and the dependence of this parameter on the magnitude of the acoustic pressure. The spatial distribution of the velocity of acoustic flow caused by cavitation is found in the one-dimensional case.</p>","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 4","pages":"973 - 979"},"PeriodicalIF":0.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143638416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Methodical Approach to Studies of Magnetic Interaction of Fine Particles in an Aqueous Suspension Using Computer Simulation","authors":"S. P. Ostapenko,&nbsp;A. S. Opalev","doi":"10.1134/S0040579524602012","DOIUrl":"10.1134/S0040579524602012","url":null,"abstract":"<p>The need to increase the efficiency of mining operations determines the relevance of studying the properties of fine mineral particles for their extraction and reduction of environmental pollution. The development of approaches to studying the magnetic interaction of fine particles is of scientific and practical importance and is associated with complexity of calculating the superposition of their fields when solving the problem of controlling the magnetic properties of the suspension. The work describes a computer model of the dynamics of magnetic particle interaction developed with account for their aggregation under the impact of the magnetic dipole–dipole interaction and the destruction of aggregates during thermal (Brownian) motion in order to predict the magnetic properties of the suspension using the example of magnetite from deposits of the Zaimandrovskii iron ore region. The calculation shows that the electrostatic and dispersion interactions do not have a significant effect on the interaction dynamics of micron and submicron particles of magnetite with account for the experimentally measured zeta potential and the Hamaker’s constant. A procedure is developed for calibrating the computer model of the interaction dynamics of magnetic particles using the temperature dependence of the coefficient of translational diffusion of magnetite particles and the concentration dependence of the magnetic susceptibility of the suspension. An array of calculated values of the diffusion coefficient of the model particles and the initial magnetic susceptibility of their system is formed in a wide range of computer model parameters. A procedure is developed for linking the calculated and experimental data by varying the normalization parameters of the particle size, viscosity of the medium, and thermal energy in order to minimize the maximum discrepancy between the values. The necessity is established of taking into account the change in magnetic properties with a decrease in the size of magnetite particles during the calibration of the magnetic susceptibility of the model system. The developed methodological approach ensures good convergence of the calculated and experimental data and makes it possible to visualize the aggregation of the model particles as the result of dipole–dipole interactions. The developed computer model of the interaction dynamics of magnetic particles can be used to study the effect of an external magnetic field on the aggregation ability of fine magnetite particles in order to control their extraction in separation processes.</p>","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 4","pages":"1293 - 1299"},"PeriodicalIF":0.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143638287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computer Simulation of the Flow of Non-Newtonian Two-Phase media in Areas of Complex Geometry","authors":"R. I. Ibyatov,&nbsp;F. G. Akhmadiev,&nbsp;R. A. Galimov,&nbsp;D. M. Galiev","doi":"10.1134/S0040579524602000","DOIUrl":"10.1134/S0040579524602000","url":null,"abstract":"&lt;p&gt;Computer modeling of the flow of two-phase non-Newtonian media in areas of complex geometry, which often applies to the elements of various technological equipment, is considered. The basis of the computer modeling is a mathematical model of the flow of non-Newtonian two-phase media in channels and pipes with various curved walls. To construct a mathematical model of the flow of non-Newtonian two-phase media, the equations of conservation of mass and momentum of the mechanics of heterogeneous media are used with the corresponding closing relations for the force of interphase interaction and the rheological law of the state of the medium. Simplified equations taking into account flow features close to one-dimensional, written in an orthogonal coordinate system associated with the flow area, are solved numerically using a modified method of equal flow surfaces. An algorithm for numerical flow calculations is constructed for computer simulation of the process. In the numerical calculations, the location and number of surfaces of equal flow rates varies in a wide range, taking into account the characteristics of the flow, and reasonable input (initial) values of the longitudinal velocity on the streamlines are specified. Numerical calculations are carried out for areas of parabolic and conical shapes, taking into account the inlet section of the flow and the influence of the centrifugal force field. A computational experiment is performed for various values of the channel parameters, the rheological law of the state of the medium, and the flow regimes of the two-phase medium. As a result, it is found that in the initial section the flow is transformed from an initial flat profile to a parabolic one. The flow velocities slow down near the channel walls and accelerate in the center of the flow region. Because of this, in the initial section of the flow region, the streamlines are bent. Knowledge of the velocity field of the carrier phase makes it possible to determine the trajectories of motion of the dispersed phase, which is a determining factor for many technological processes. The constructed mathematical model that describes the hydrodynamic situation in the flow region allows us to conduct a computational experiment to calculate the flow of two-phase non-Newtonian media in curved channels and pipes of complex geometry using the modified method of equal flow surfaces. In this case, specific shapes of the flow region are specified by specifying the corresponding Lame coefficients for the flow region. Based on computer modeling, various flow regimes and the influence of various geometric characteristics of the channel, mass forces, and parameters of the rheological law of the state of the medium on the hydrodynamic flow conditions are studied. At different values of the nonlinearity parameters in the power law of state, the centrifugal force, with its increase, has a stronger influence on the hydrodynamic situation in the channel. The results of ","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 4","pages":"1265 - 1271"},"PeriodicalIF":0.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143638337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling of Heat- and Mass-Transfer Processes during Convective Drying of Cotton Fabrics","authors":"M. K. Kosheleva,&nbsp;O. R. Dornyak","doi":"10.1134/S0040579525600081","DOIUrl":"10.1134/S0040579525600081","url":null,"abstract":"<p>A mathematical model of heat and mass transfer in the process of convective drying of fabric in chemical technology of its finishing is presented. The equations are written for thermophysical variables averaged over the sample volume. The model controls the state of water in a capillary–porous system and takes into account the flow of the liquid phase in a bound state. Free water is motionless. Changes in the concentration of free water can occur due to phase transitions at the boundaries of the liquid and gaseous phases. The mathematical model can be considered as a variant of the well-known model of diffusion heat and mass transfer by A.V. Lykova with certain additions. In addition to the equations of moisture conductivity, thermal conductivity, and total pressure, the model includes an equation for the concentration of the vapor component of the gaseous phase. For local values of the diffusion coefficient of the liquid phase and the phase transition criterion, analytical dependences of these values on moisture content and temperature are used. The mathematical model was investigated numerically using the finite difference method. The model was validated using laboratory experiment data for cotton fabric samples of different densities, thicknesses, and weaving methods. Calculations of drying curves using the proposed model showed satisfactory agreement with experimental dependences. The contribution of two mass-transfer mechanisms associated with phase transitions and capillary flows of the liquid phase to the tissue drying process was investigated.</p>","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 4","pages":"965 - 972"},"PeriodicalIF":0.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143638418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of the Influence of Speed and Method of Melt Casting on the Development of the Axial Zone in Model Ingots","authors":"S. B. Gamanyuk,&nbsp;D. V. Rutskii,&nbsp;N. A. Zyuban,&nbsp;M. V. Kirilichev,&nbsp;D. S. Afonin,&nbsp;N. A. Burlakov","doi":"10.1134/S0040579524601924","DOIUrl":"10.1134/S0040579524601924","url":null,"abstract":"<p>The paper presents the results of laboratory studies on the influence of the method and speed of melt casting on the solidification process and the features of forming of the axial zone of a large ingot. The research is conducted using physical (cold) simulation on a model ingot weighing 19.6 t. Sodium thiosulfate (crystalline hyposulfite) is used as the simulating solution. The casting of the melt into the mold–crystallizer is performed from the top. It is shown that changing the casting speed of the melt significantly affects the length of the axial zone. It is established that a decrease in the casting speed of the melt leads to an increase in the directionality of crystallization and an improvement in the structure of the axial zone of the ingot. It is found that model ingots that were cast with topping up of the founding head with the melt after a certain interval of time post-filling solidify 1.4 times faster than ingots cast using classical technology.</p>","PeriodicalId":798,"journal":{"name":"Theoretical Foundations of Chemical Engineering","volume":"58 4","pages":"1258 - 1264"},"PeriodicalIF":0.7,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143638282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}