#### Volume 90, №2

**SEPARATION POTENTIAL FOR MULTICOMPONENT MIXTURES: STATE-OF-THE ART OF THE PROBLEM**

Various approaches used in introducing a separation potential (value function) for multicomponent mixtures have been analyzed. It has been shown that all known potentials do not satisfy the Dirac–Peierls axioms for a binary mixture of uranium isotopes, which makes their practical application diffi cult. This is mainly due to the impossibility of constructing a "standard" cascade, whose role in the case of separation of binary mixtures is played by the ideal cascade. As a result, the only universal search method for optimal parameters of the separation cascade is their numerical optimization by the criterion of the minimum number of separation elements in it.

**Author:**
G. A. Sulaberidze, V. D. Borisevich, and A. Yu. Smirnov

**Keywords:**
value function, separation power, separation element, separation cascade

**Page:**
251

**MATHEMATICAL MODEL OF NONSTATIONARY SEPARATION PROCESSES PROCEEDING IN THE CASCADE OF GAS CENTRIFUGES IN THE PROCESS OF SEPARATION OF MULTICOMPONENT ISOTOPE MIXTURES**

We have developed and realized on software a mathematical model of the nonstationary separation processes proceeding in the cascades of gas centrifuges in the process of separation of multicomponent isotope mixtures. With the use of this model the parameters of the separation process of germanium isotopes have been calculated. It has been shown that the model adequately describes the nonstationary processes in the cascade and is suitable for calculating their parameters in the process of separation of multicomponent isotope mixtures.

**Author:**
A. A. Orlov, A. A. Ushakov, and V. P. Sovach

**Keywords:**
gas centrifuge, multicomponent isotope mixture, separation, modeling, isotope, nonstationary process

**Page:**
258

**HEAT TRANSFER IN FILM BOILING OF SUBCOOLED LIQUIDS: NEW EXPERIMENTAL RESULTS AND COMPUTATIONAL EQUATIONS**

This paper presents new experimental data on the film boiling of ethanol on a copper ball at pressures up to 0.8 MPa and subcooling temperatures of 53–166 K. An analysis is made of the reasons for the discrepancy between the experimental data on the heat transfer in stable film boiling of subcooled liquid and the results of calculations with the use of the approximate model developed earlier by us and its correction has been made. A semi-empirical computing equation is proposed that describes all experimental data on the fi lm boiling of nonaqueous liquids subcooled to 170 K at pressures of 0.1–1.0 MPa.

**Author:**
V. V. Yagov, A. R. Zabirov, P. K. Kanin, and M. A. Denisov

**Keywords:**
fi lm boiling, subcooled liquid, cooling thermogram, free convection

**Page:**
266

**FLOW OF A METHANE VAPOR–DROP MIXTURE IN A CHANNEL OF VARIABLE CROSS SECTION**

Results of numerical investigation of the dynamics of a methane vapor–drop mixture in a channel of variable cross section are presented. Calculations were performed on the basis of a one-velocity, one-temperature model in the diffusion approximation with the use of the scheme of a nonequilibrium phase transition. A computational method was verified by comparison of the results of calculations of the dynamics of a water vapor flow with experimental data. The temperature fields and the partial density of the condensate in a Laval nozzle were determined depending on the temperature of the flow at the input of the channel and on the pressure drop in it.

**Author:**
S. N. Arslanova, R. I. Bayanov, A. L. Tukmakov, and V. G. Tonkonoga

**Keywords:**
vapor–drop gas mixture, one-velocity and one-temperature model, diffusion approximation, nonequilibrium phase transition, McCormack scheme

**Page:**
276

**ON STARTUP OF A FLUIDIZED-BED BOILER**

The process of heating a granular bed under conditions of thermal fluidization with heat supplied through the upper boundary of the bed and through its gas distributor is investigated.

**Author:**
E. A. Pitsukha, Yu. S. Teplitskii, A. R. Roslik, R. L. Is′emin, D. V. Klimov, A. V. Mikhalev, V. A. Borodulya and V. A. Dubina

**Keywords:**
fixed granular bed, fluidized (bubbling) bed, strong-discontinuity surface, startup of a boile

**Page:**
282

**HEAT AND MASS TRANSFER IN THE CHEMICAL VAPOR DEPOSITION OF SILICON CARBIDE IN A POROUS CARBON–CARBON COMPOSITE MATERIAL FOR A HEAT SHIELD**

Physical and mathematical simulations of the chemical vapor deposition of silicon carbide in a porous carbon–carbon composite material in a chemical vapor deposition reactor for formation of a matrix of a carbon–ceramic composite material for a heat shield of an aerospace aircraft have been performed. Results of parametric calculations of the heat and mass transfer at the macro- and microlevels in representative elements of the microstructure of carbon– carbon composite materials different in residual porosity at different temperatures in the reaction zone of the reactor are presented. Features of compaction of the pore space of a carbon–carbon composite material by a silicon-carbide matrix depending on the technological parameters of the reaction medium were analyzed.

**Author:**
S. V. Reznik, K. V. Mikhailovskii, and P. V. Prosuntsov

**Keywords:**
thermal protection, chemical vapor deposition, carbon–ceramic composite material, silicon-carbide matrix

**Page:**
291

**ACOUSTICS OF A POLYDISPERSE VAPOR–GAS BUBBLES-LADEN LIQUID**

A mathematical model is presented that determines the propagation of acoustic waves in a liquid containing polydisperse vapor–gas bubbles with account for mass transfer processes. A system of integrodifferential equations of a disturbed motion of a two-phase mixture is written, and a dispersion relation is obtained. A general expression for the equilibrium velocity of sound has been found for a vapor–gas liquid mixture, and the influence of vapor concentration and of the volume content of bubbles on the value of the equilibrium velocity of sound has been analyzed. In particular cases, expressions of the equilibrium velocity of sound are presented for gas–liquid and vapor–liquid mixtures, and satisfactory agreement of the obtained values with the familiar experimental data has been obtained. The results of comparison of the dispersion curves of phase velocity and of the attenuation coeffi cient for a mixture of water with vapor–air bubbles at different values of the initial concentration of vapor in bubbles are given

**Author:**
D. A. Gubaidullin and Yu. V. Fedorov

**Keywords:**
acoustics, bubbly liquid, mass transfer, dispersion relation

**Page:**
301

**INCREASING THE ENERGY EFFICIENCY OF THE PROCESS OF OSCILLATING VACUUM-CONDUCTIVE DRYING OF WOOD BY MEANS OF A HEAT PUMP**

The article presents the results of investigations of the energy-saving technology of oscillating vacuum-conductive drying of wood in which the heat of the moisture evaporated from the material in the stage of vacuum treatment is fed by a heat pump for raising the temperature of the material in the stage of heating. A method for calculating the rate of moisture removal from a heated wood in the process of vacuum treatment depending on the vacuum depth, temperature, moisture content, and of the material thickness has been developed.

**Author:**
R. R. Safin, R. R. Khasanshin, I. F. Khakimzyanov, Sh. R. Mukhametzyanov, and P. A. Kainov

**Keywords:**
wood, drying, vacuum, energy saving, heat pump

**Page:**
310

**ANALYTICAL AND EXPERIMENTAL STUDY OF THE AIR RECIRCULATION IN A LOADING POROUS TUBE WITH A COMBINED BYPASS CHAMBER**

The present paper considers the stream of air entrained by a stream of free-falling material in a vertical porous loading tube contained in a tube of large radius (bypass chamber). The ascending air in the bypass chamber is recirculated through both holes uniformly perforated in the chute walls and end holes at the ends of the bypass chamber. The parameters providing the greatest decrease in the volume of ejected air due to recirculation have been determined by solving the differential equations of motion of ejected air (entrained by the stream of free-falling material) and of recirculated air. The effect of decrease in the volume of ejected air due to the air recirculation in the "loading tube–bypass chamber" system has been confirmed experimentally.

**Author:**
O. A. Averkova, I. V. Kryukov, I. N. Logachev, and K. I. Logachev

**Keywords:**
aspiration, free-flowing materials, air ejection, recirculation

**Page:**
318

**FILLS OF CO-SIZED AND DIFFERENT-SIZED GRANULES AS QUASI-ORDERED STRUCTURES**

From the measured data of the packing density γ (and/or porosity ω) of filling media of co-sized or different-sized granules, the authors evaluate the coordination number of a sphere granule N and the acceptable type of cell as a self-sufficient element of a conditionally ordered structure. It is shown that for the expansive class of filling media (of identical spherical granules, nearly identical granules, and also granules differing no more than twice in size), the medium′s structure may be considered to consist of cells close to square-rhombic ones (γ = 0.605 and ω = 0.395) by assuming that N ≈ 8. A filling media with different-sized granules (granule size differs more than twice) may be considered structures with combinations of cells like rhombic, rhombic-diagonal, and square-rhombic diagonal cells, for which γ ≥ 0.7 and ω ≤ 0.3. Here, N is assumed from N ≈ 8 to N ≈ 12 in accordance with the established relationship between N and γ (and/or ω).

**Author:**
A. A. Sandulyak, V. A. Ershova, D. A. Sandulyak, A. V. Sandulyak, and M. N. Polismakova

**Keywords:**
polyspherical medium, ordered structure, disordered structure, packing density, porosity, coordination number.

**Page:**
329

**PROPERTIES OF ELASTOMERIC COMPOSITES WITH FUNCTIONALIZED CARBON NANOMATERIAL**

The influence of two different nanomaterials on the properties of elastomeric composites based on general- and special-purpose rubbers has been investigated. For the elastomeric matrix, we used a combination of synthetic polyisopropene (SKI-3) and stereoregular butadiene (SKD) caoutchoucs in one case and butadiene-nitrile caoutchouc containing 27–30% of bound acrylic acid nitrile (BNKS-28) in the other case. For additives, nanomaterials of two types were used. To determine the degree of interaction of the additives with the elastomeric matrix, complex tests of rubber mixes and vulcanizates based on them were carried out, in which the following indices were determined: the Mooney viscosity, the relaxation and vulcanization characteristics of the mixes, the elastic-strength properties of the vulcanizates before and after thermal ageing, their resistance to thermal ageing, and the mechanical loss tangent.

**Author:**
Zh. S. Shashok, N. R. Prokopchuk, K. V. Vishnevskii, A. V. Krauklis, K. O. Borisevich, I. O. Borisevich, and S. A. Zhdanok

**Keywords:**
polyisopropene caoutchouc, butadiene-nitrile caoutchouc, rubber, carbon nanomaterials, nanotubes, nanofi bers, functionalization

**Page:**
336

**MODIFICATION OF THE MATHEMATICAL MODEL OF THE THERMOELECTRIC MODULE OF A THERMOSTATING COATING **

A modification has been made of the previously constructed mathematical model of a fragment of a flat thermostating coating including a thermoelectric module based on the variation formulation of the stationary problem of heat conduction in an inhomogeneous solid body. With the use of the Fourier finite integral transform the dependences have been obtained for calculating the temperature distribution in the heat insulating layer in the vicinity of the thermoelectric element and commutating conductors. This enabled us to refine one of the diagnostic variables of the model — the total heat resistance of the heat insulator between commutating plates and conductors of the thermoelectric module infl uencing the energy characteristics of the thermostating coating under investigation.

**Author:**
V. S. Zarubin, G. N. Kuvyrkin, and I. Yu. Savel′eva

**Keywords:**
thermostating coating, thermoelectric module, Fourier finite integral transform

**Page:**
344

**A METHOD OF DESCRIBING HEAT TRANSFER BETWEEN A GAS BUBBLE AND A LIQUID**

A method for describing heat transfer between a gas bubble and a liquid is suggested based on the application of the apparatus of mathematical physics. An expression for the heat flux at the bubble boundary has been derived.

**Author:**
N. S. Khabeev

**Keywords:**
heat transfer, small gas bubble, bubble curtain

**Page:**
353

**MATHEMATICAL MODEL OF THE RADIATIVE HEAT EXCHANGE IN THE SELECTIVE GASES OF A DIFFUSION FLAME**

Possibilities of improvement of the differential model of radiative transfer, used in engineering investigations of the heat exchange in the products of combustion of a gas fuel, were analyzed. The equations, boundary conditions, and algorithms of this model were refined. A method of calculating the local absorption coefficients of selective gases, involved in differential equations of radiative transfer, has been determined

**Author:**
V. A. Kuznetsov

**Keywords:**
selective gases, absorption of radiation, radiative heat transfer, transfer equations

**Page:**
357

**THE BOUNDARY FUNCTION METHOD. FUNDAMENTALS**

The boundary function method is proposed for solving applied problems of mathematical physics in the region defined by a partial differential equation of the general form involving constant or variable coefficients with a Dirichlet, Neumann, or Robin boundary condition. In this method, the desired function is defined by a power polynomial, and a boundary function represented in the form of the desired function or its derivative at one of the boundary points is introduced. Different sequences of boundary equations have been set up with the use of differential operators. Systems of linear algebraic equations constructed on the basis of these sequences allow one to determine the coefficients of a power polynomial. Constitutive equations have been derived for initial boundary-value problems of all the main types. With these equations, an initial boundary-value problem is transformed into the Cauchy problem for the boundary function. The determination of the boundary function by its derivative with respect to the time coordinate completes the solution of the problem.

**Author:**
V. A. Kot

**Keywords:**
method of weighted temperature function, boundary function method, approximate method, boundary method, boundary equations

**Page:**
366

**A NEW EQUATION FOR THE THERMAL CONDUCTIVITY OF LIQUID REFRIGERANTS OVER WIDE TEMPERATURE AND PRESSURE RANGES**

This work presents a new simple equation for the thermal conductivity of liquid refrigerants as a function of the reduced temperature, molecular mass, reduced pressure, and the acentric factor. This model is applied for predicting the thermal conductivity of the refrigerants over the whole temperature and pressure ranges. A set of 915 data on the thermal conductivity for 30 refrigerants has been used. These refrigerants were divided into three categories on the basis of various chemical halogens forming the compounds and were investigated individually. For the data sets, the average error of the proposed model was 4.82%. The results show that the new equation can be used with confi dence in engineering calculations.

**Author:**
Ali Akbar Amooey

**Keywords:**
liquid refrigerants, thermal conductivity, equation

**Page:**
392

**NUMERICAL STUDY OF PARTICLE HEATING IN A PLASMA JET**

The motion of particles axially injected into the plasma spray process has been studied using a one-dimensional model. The effect of the initial particle velocity and particle diameter on the final particle velocity and temperature was evaluated. The aim of the work is to optimize the spraying process by defining the favorable particle injection velocity, considering a wide range of velocity and temperature of the plasma jet.

**Author:**
A. Essiptchouk, G. Petraconi, F. R. Caliari, F. S. Miranda, M. Yesipchuk, and A. Petraconi

**Keywords:**
high-velocity plasma spray, cold spray, plasma powder spraying, computer modeling, process control

**Page:**
397

**NUMERICAL INVESTIGATION OF THE AIR FLOWS IN THE CAB OF A TRUCK IN THREE DIFFERENT REGIMES OF ITS VENTILATION**

Different variants of ventilation of the cab of a truck were investigated by numerical simulation methods. An unsteady viscous gas flow was numerically simulated using the VP2/3 package. In the process of numerical simulation of this flow, the Reynolds equations closed with the use of the differential k–ω model of turbulence in the SST modification of Menter were solved numerically. On the basis of analysis of the fields of the velocity, pressure, and turbulence characteristics of the air flows in the truck cab, obtained as a result of their numerical simulation, the efficiency of ventilation of this cab was estimated.

**Author:**
S. A. Isaev, A. E. Usachov, P. A. Baranov, T. D. Glushkov, and M. V. Gureev

**Keywords:**
numerical simulation, ventilation, truck cab, turbulence, MSST, VP2/3 package

**Page:**
405

**MODEL GAS-DYNAMICAL PROBLEMS POSSESSING CYLINDRICAL AND SPHERICAL SYMMETRY AND THEIR SOLUTION WITH THE AID OF WENO SCHEMES**

The solution of a number of problems of gas dynamics that are associated with cylindrically and spherically symmetric nonstationary compression of an inviscid gas is considered. Discretization of the Euler equations is carried out with the aid of the method of fi nite volumes and difference schemes of the WENO type. The results of numerical simulation are compared with exact solutions and with the results of the calculations available in the literature. The solutions of two- and three-dimensional problems possessing cylindrical and spherical symmetry are given in comparison with the solutions obtained in one-dimensional formulation. The calculations with the use of WENO schemes make it possible to obtain an exact and monotonic solution of the problem in the presence of both weak and strong gasdynamical discontinuities.

**Author:**
P. V. Bulat and K. N. Volkov

**Keywords:**
gas dynamics, symmetry property, difference scheme, shock wave, rarefaction wave, contact discontinuity, Riemann problem

**Page:**
412

**DIRECT SIMULATION OF THE RELAXATION OF SEVERAL PARTICLES BEHIND TRANSMITTED SHOCK WAVES**

The interaction of a shock wave with a system of relaxing particles was simulated numerically. A detailed wave pattern of the nonstationary interaction of a transmitted shock wave with moving particles has been obtained. The computational technique has been verified by the experimental data on the dynamics of particles behind the shock wave. It has been shown that the approximate model of calculating velocity relaxations is not effective in the case of mutual influence of particles when some particles are in the wind shadow of other particles.

**Author:**
I. A. Bedarev and A. V. Fedorov

**Keywords:**
shock wave, velocity relaxation of particles, numerical simulation

**Page:**
423

**DEVELOPMENT OF RICHTMYER–MESHKOV INSTABILITY AS A RESULT OF THE TRANSMISSION OF A SHOCK WAVE THROUGH A CYLINDRICAL STRUCTURE OF HEAVY GAS**

On the basis of a mathematical model of the mechanics of a two-velocity two-temperature mixture of light and heavy gases with different pressures, the dynamics of a heavy-gas droplet in the case of incidence of a shock wave on it is numerically studied within the framework of two-dimensional nonstationary flow of the mixture. An analysis of experimental data on the dependence of the spatial expansion of the droplet on time has shown their satisfactory agreement with calculated data

**Author:**
K. I. Zyryanov, G. A. Ruev, and A. V. Fedorov

**Keywords:**
shock wave, droplet, mixing layer, Richtmyer–Meshkov instability, two-velocity two-temperature dynamics of gas mixtures

**Page:**
430

**EFFECT OF DIFFERENTIAL DIFFUSION IN TWO-COMPONENT MEDIA**

Examples are presented of an exact solution of a nonstationary problem on the development of convection in a binary mixture (seawater) near an infi nite vertical surface in which the buoyancy disturbances are determined both by the temperature and by the disturbances of the impurity (salt) concentration. Consideration is given to the development of convection in a homogeneous medium near an infinite vertical surface at whose boundary specifi cation is made of constant (after ″switching on″ at the initial moment) heat fluxes and impurities or variations of these substances, i.e., problems with boundary conditions of 1st and 2nd kind are considered. The obtained analytical solutions demonstrate the possibility of a nontrivial effect associated with the difference in the values of the coefficients of transfer of two substances: the infl ows of positive buoyancy may lead, contrary to intuitive notions, to the origination of descending motion of the medium rather than the ascending one. Clarifi cation is provided for the physical meaning of such effects, which can be substantial, for example, in melting of sea ice

**Author:**
L. Kh. Ingel′

**Keywords:**
convection, two-component medium, differential diffusion, seawater

**Page:**
437

**BIFURCATIONS OF EQUILIBRIUM STATES OF A FLUID LAYER INSIDE A ROTATING CYLINDER**

The relative equilibrium of a layer of viscous fluid on the interior surface of a rotating cylinder has been investigated. The influence of the physical properties of the fluid, the difference of the pressures in the layer and the environment, the rotational velocity and radius of the cylinder, and the thickness of the layer on the form of its free surface have been studied. The shapes of the surface and the possibility of branching of solutions in a nonlinear formulation have been investigated; the complete branches of bifurcation curves have been constructed

**Author:**
P. N. Konon and A. V. Zhuk

**Keywords:**
bifurcation, branching of solutions, rotation of a cylinder, relative equilibrium, free surface

**Page:**
442

**INFLUENCE OF THE CONFIGURATION ELEMENTS OF A MODEL OF A SUPERSONIC PASSENGER AIRCRAFT ON THE PARAMETERS OF SONIC BOOM**

The author gives results of parametric calculations of shock-boom levels in the case of flow with a free-stream Mach number of 2.03 past configurations of a supersonic aircraft. The calculations are aimed at investigating the influence of the relative position of basic elements and their geometric shape on the aerodynamic quality of the confi guration and on the parameters of shock boom at great distances from the perturbation source. The geometric models of the confi gurations were formed by combining and joining component elements: the body, the front wing, and the rear tapered wing with root dogtooth extension. From an analysis of all the considered models of tandem configurations with account of the resolvability of shock waves in a perturbed profile compared to the monoplane configuration, the optimum confi guration has been singled out that ensures a reduction of 24% in the intensity level of shock boom with an increase of 0.24% in its aerodynamic quality.

**Author:**
V. F. Volkov

**Keywords:**
supersonic fl ow, shock wave, shock boom, tandem confi guration, monoplane, perturbation source

**Page:**
449

**VIBRATION OF TUBE BUNDLES IN CROSS WATER FLOW**

Results of vibration testing of an experimental tube bundle of 72 tubes of diameter 0.012 m in the case of coolingwater flow across the tubes with different versions of installation of baffles are described. The influence of the displacement of the baffles on the parameters of vibration of the tube bundle is determined.

**Author:**
I. M. Dikarev, E. A. Loshkareva, and A. Yu. Kartuesova

**Keywords:**
tube bundle, vibration, fl ow across tubes

**Page:**
461

**ASSESSMENT AND CONTROL OF DETONATION HAZARD OF SILANE-CONTAINING MIXTURES**

A formula for calculating the induction period of a silane–air gas mixture has been proposed. The dimension of a detonation cell and the energy of direct initiation of gaseous detonation were assessed. Consideration has been given to the issue of control of the parameters of detonation of silane-containing mixtures. The parameters of Chapman–Jouguet detonation, the relative dimension of the cell of a detonation wave, and also the parameters of explosion at constant pressure and volume in a stoichiometric silane–air gas mixture with additions of chemically inert microparticles (Al2O3) have been calculated.

A series of experiments was conducted on measurement of the pressure profi le resulting from the explosion of the silane–air mixture in a volume of cubic shape with the known average fuel–oxidant ratio. The distribution of the fuel during the silane jet flowing out into this volume was visualized. The distribution of silane in a cloud in its outflow into the cubically shaped volume and in a high-speed jet flowing out into an unbounded space was calculated. The performed investigations can be useful in evaluating the comparative efficiency of explosion of clouds of silane– and hydrocarbon–air mixtures

**Author:**
P. A. Fomin, A. V. Fedorov, D. A. Tropin, and J.-R. Chen

**Keywords:**
silane, induction period, detonation, cell, explosion, gas–particles mixture, explosion safety

**Page:**
465

**GAS BURNER WITH IMPROVED ECONOMICAL EFFICIENCY**

A gas burner for domestic stoves has been developed whose distinctive feature is the presence of a heat-transfer intensifier in the form of a rod with a developed heat-transfer surface in it. Investigation results are given that enable us to state the economical effi ciency of the proposed gas burner compared to the existing analogs.

**Author:**
K. V. Altunin

**Keywords:**
gas burner, heat-transfer intensifi er, gas

**Page:**
480

**APPLICATION OF A POLYMER COMPOUND TO A PLANE SURFACE BY AN ELASTIC PLATE**

A mathematical model of the hydroelasticity of a flow of a non-Newtonian fl uid in a wedge-shaped clearance with an elastic wall has been constructed. This wall represents a thin cylindrical elastic shell inextensible along its central axis, for which the Kirchhoff–Love hypotheses are true. A fl uid fl ow in the clearance was simulated in the approximation of the Reynolds lubrication theory with the use of an asymptotic approximation for the second invariant of the strain rate tensor. Results of numerical investigations with the mathematical model proposed are presented.

**Author:**
V. M. Shapovalov

**Keywords:**
mathematical simulation, non-Newtonian fluid, hydroelasticity, pressure, elastic plate, bend, force, moment

**Page:**
484

**EXPERIMENTAL STUDY OF THERMOPHYSICAL PROPERTIES OF PEAT FUEL**

A study has been made of thermophysical properties of peat pellets of higher-than-average reactivity due to the

pretreatment of the raw material. A synchronous differential analysis of the produced pellets was performed to

determine the gaseous products of their decomposition by the mass-spectroscopy method. The parameters of the

mass loss rate, the heat-release function, the activation energy, the rate constant of the combustion reaction, and the

volatile yield were compared to the properties of pellets compressed by the traditional method on a matrix pelletizer.

It has been determined that as a result of the peat pretreatment, the yield of volatile components increases and the

activation energy of the combustion reaction decreases by 17 and 30% respectively compared with the raw fuel. This

determines its prospects for burning in an atomized state at coal-fi red thermal electric power plants.

**Author:**
A. S. Mikhailov, Sh. A. Piralishvili, E. G. Stepanov, and N. S. Spesivtseva

**Keywords:**
peat, pellets, reactive properties, volatile yield, thermal analysis, humic acids

**Page:**
491

**MICROWAVE DRYING OF MOIST COALS**

Physical principles and examples of practical implementation of drying large bodies of coal by microwave radiation are

considered. It is shown that energy consumption in microwave drying of brown coals decreases to 1.5–1.8 (kW·h)/ kg

as compared with traditional types of drying, for which the expenditures of energy amount to 3.0 (kW·h)/kg. In using

microwave drying, the technological time of drying decreases to 4 h, whereas the time of convective drying, with

other things being equal, comes to 8–20 h. Parallel with microwave radiation drying, grinding of a fuel takes place,

as well as entrainment of such toxic and ecologically harmful elements as mercury, chlorine, phosphorus, sulfur, and

nitrogen. An analysis of the prospects of using a microwave energy for drying coal fuel has shown that microwave

radiation makes it possible to considerably economize in energy, increase explosional safety, improve the ecological

situation, and reduce the metal content and overall dimensions of the equipment.

**Author:**
Vl. V. Salomatov, V. A. Karelin, S. O. Sladkov, and Vas. V. Salomatov

**Keywords:**
coal, microwave radiation, drying, dispersion, dielectric heating

**Page:**
497