Furnace Chamber Research Articles

Use of temporary gas flow to improve the efficiency of metallurgical units operation

This paper presents the results of industrial tests on dust deposition due to the use of an unsteady gas flow. JSC SUMZ (Revda) applied the technology with the use of acoustic radiators to organize in-furnace dust deposition at Vanyukov furnace. The design of the radiator included a nozzle pipe, air nozzle, resonator and focusing surface. Based on the surface area of the furnace molten pool and recommended specific acoustic power values for in-furnace dust condensing, the total acoustic field sound power was calculated. The optimal number and location of acoustic radiators was determined. The analysis of the data of industrial tests of the use of the acoustic field energy in the working space of the PZhV, as well as the results of tests on the converter No. 2 of JSC ‘SUMZ’, the cyclone of the firing multi-hearth furnace of JSC ‘SVYATOGOR’, the dust chamber of the Waelz furnace and cleaning of the heat exchange surfaces of the boiler on waste gases (JSC ‘Chelyabinsk Zinc Plant’).

Optimal Tube Bundle Arrangements in Side-Fired Methane Steam Reforming Furnaces

Steam methane reforming processes represent the economically most competitive processes for the production of synthesis gas and hydrogen despite their high energy costs. Although there is a strong need for highly resource-efficient production, literature on the optimal design of reformers remains scarce due to the inherently high complexity of these processes. This contribution addresses design aspects of reformers for the case study of a side-fired reformer. Based on a two-dimensional furnace representation heat transfer and the optimal tube bundle arrangement for a fixed furnace chamber are investigated using simulation-based optimization with both a lean radiation-based model and a computational fluid dynamics model that enables the consideration of fuel efficiency. Radiative heat transfer prevails in the reformer on the furnace side and inter-tube distances of at least three diameters are optimal within the investigated design space. The line arrangement of reformer tubes is beneficial in terms of total heat transferred, fuel efficiency as well as the homogeneity of the tube surface temperatures. These findings pave the way for further studies such as three-dimensional design aspects.

Utilization of rice husk biomass in the conventional corn dryer based on the heat exchanger pipes diameter

Utilizing rice husk biomass for drying corn is an alternative solution for drying corn in direct sunlight. This is done through the conversion of thermal energy with heat-exchanging furnaces. This model provides opportunity that the drying process is independently of the weather condition and gain more hygienic products. In addition, it creates energy independence through the use of waste that has an energy value is quite high. Utilization of rice husks by optimizing the performance of heat exchangers through the application of stainless-steel pipes. The diameter of the pipes varies, namely 1 inch, ¾ inch, and ½ inch. The conventional dryer design has dimensions of drying chamber (600 × 536 x 536) mm3 and furnace (800 × 500 x 500) mm3. Nine of heat exchanger pipes are arranged in parallel to one air flow path. The results show the utilization of rice husk biomass provides satisfactory performance on drying 4 kg of corn. The average temperature of the drying chamber, which is based on the outlet temperature of the heat exchanger pipes diameter of 1 inch, ¾ inch, and ½ inch are 91.20 ± 0.70 °C, 73.95 ± 0.65 °C, and 58.27 ± 0.48 °C, respectively.

Experimental study on the seismic performance of RC columns retrofitted by lap-spliced textile-reinforced mortar jackets after high-temperature exposure

The present experimental study investigated the seismic performance of reinforced concrete columns retrofitted by lap-spliced TRM jackets after high-temperature exposure. A total of eight column specimens were fabricated and tested, with the two main parameters being the amount of carbon fiber mesh, and the surface treatment method in lap-sliced regions. High-temperature tests were performed in a furnace chamber with moderate temperature up to 250 °C, followed by ultrasonic image scanning and cyclic loading tests. The experimental results from ultrasonic image scanning and cyclic loading tests illustrate that even after exposure to high temperature, the retrofitted solution using TRM jackets with the proposed lap-spliced details was effective, in terms of increasing both the strength and the deformation capacity. In addition, an analytical model to evaluate idealized backbone curves used for nonlinear analysis of columns retrofitted by TRM jackets subjected to high temperatures was proposed and showed reasonable agreement with the experimental results.

The effects of thermal pyrolysis and decomposition products on explosive characteristics of flufenacet and sulfentrazone

Thermal pyrolysis and decomposition products of flufenacet and sulfentrazone powders were tested by thermogravimetric analysis (TGA), TGA coupled with Fourier transform infrared spectroscopy and pyrolysis-gas chromatography/mass spectrometry. Besides, the explosion sensitivity (minimum ignition temperature, minimum ignition energy, minimum explosion concentration) and explosion severity (maximum explosion pressure, and the maximum rate of pressure rise) were measured in standard 20-L spherical chamber, Hartmann apparatus and Godbert-Greenwald Furnace apparatus. Moreover, the effect of thermal pyrolysis characteristics on the explosion sensitivity and severity of flufenacet and sulfentrazone dust clouds were analyzed. The results indicated that flufenacet had lower decompose temperature, and smaller activation energy than sulfentrazone. Both flufenacet and sulfentrazone expressed flammable and toxic substance during their decomposition. Greater amount of products with higher flammability were expressed from flufenacet compared with sulfentrazone. The flufenacet had lower explosion sensitivity than sulfentrazone In addition, the flufenacet’s explosion severity was higher than sulfentrazone, which was mainly determined by the larger number of combustible gases from flufenacet. What’s more, both the two herbicide powders can lead to serious dust explosion accidents due to their explosive and toxic characteristics.

A simulation model for controlling mass transfer of vapor silicon and volatile impurities with gas flow guidance during refining of silicon

The mass transfer behavior of vapor silicon (Si) and volatile impurities during refining of Si by electron beam melting is still unclear. In present work, with gas flow guidance, the mass transfer mechanism of vapor Si and volatile impurities, and corresponding heat transfer rule in the furnace chamber are investigated by simulation and experiment. Numerical simulation shows that vapor Si is preferentially transferred to the outlet, and temperature in the outlet is lower than the solidification temperature of vapor Si when gas flow is fixed at 0° and 1.16 m s−1 (optimal conditions). Experimental results show that volatile impurities are effectively removed (P and Al both are less than 0.01 ppmw in the refined Si ingot with >99% of removal efficiency). Moreover, volatile impurities flux positively increases with increase of vapor Si flux. Gas flow significantly gathers the vapor Si in the outlet, reinforcing evaporation kinetics of molten Si and volatile impurities, which demonstrates the numerical simulation model is feasible to control the mass transfer and evaporation kinetics. Gas flow guidance may be a promising way to improve volatile impurities removal from Si.

ЧИСЛЕННОЕ ИССЛЕДОВАНИЕ ВЛИЯНИЯ ИЗБЫТКА ПЕРВИЧНОГО ВОЗДУХА НА ПРОЦЕССЫ ГОРЕНИЯ В ТОПОЧНОЙ КАМЕРЕ ЭНЕРГЕТИЧЕСКОГО КОТЛА С МНОГОКАНАЛЬНЫМИ ВИХРЕВЫМИ ГОРЕЛКАМИ

Актуальность исследования обусловлена необходимостью поиска оптимальных решений по организации сжигания полифракционного пылеугольного топлива на действующих и новых тепловых электрических станциях с учетом снижения выбросов вредных веществ, в частности оксидов азота. За последнее десятилетие значительно выросли экологические требования, направленные на регулирование выбросов от угольных электростанций в атмосферу, которые были спроектированы в целях повышения тепловой эффективности. В настоящее время проблема совершенствования экологических параметров ТЭС в России обостряется тем, что большинство действующих станций не удовлетворяют современным экологическим нормам и требованиям. Цель: установить влияние организации сжигания твердого топлива на топочные процессы при минимальной возможной модернизации действующего парового котла с использованием низкоэмиссионных горелочных устройств. Объекты: топочная камера энергетического котла в проектном исполнении и в варианте с заменой проектных горелочных устройств на низкоэмиссионные. Методы. Численное исследование проведено с использованием пакета прикладных программ Ansys Fluent v.12.1. Математическое моделирование физико-химических процессов в топочной камере на основе Эйлеро–Лагранжева подхода, который позволяет выявить главные взаимодействия процессов переноса частиц. Математические модели горения угольной пыли с кинетическими параметрами заданы и включены в код в качестве пользовательских функций. Результаты. Разработана математическая модель на основе пакета прикладных программ с качественным представлением сложных физико-химических процессов в объеме топочной камеры. Дана оценка возможности организации сжигания каменного угля в низкоэмиссионных горелочных устройствах с учетом оптимального соотношения первичного и вторичного воздуха без изменения установочных углов лопаточных заверителей. В данном исследовании установлено снижение концентрации оксидов азота на 14 % при замене проектных двухканальных вихревых горелочных устройств на низкоэмиссионные.

Characterization of Oxidation Behavior of Mn Fumes Generated in the Vacuum Treatment of Melting Mn Steels

Herein, the phase, composition, morphologies, particle size distribution, and specific surface area of Mn oxide fumes generated after the vacuum treatment of melting Mn steels with different initial Mn contents are characterized. The thermodynamic calculation results reveal that for a given temperature and pressure, Mn vapor generation increases with increasing initial Mn content in steel. Moreover, the experimental results find that the amount of the Mn oxide fumes on the vacuum chamber after vacuum processing gradually increases with increasing initial Mn content in the melt. The fumes on the crucible generated after vacuum processing are composed of mainly coral‐shaped Mn3O4 with the size of 500 nm and a small amount of spherical‐like Mn2O3 with the sizes of 50–200 nm. Meanwhile, the fumes deposited on the furnace chamber contain Mn nanoparticles with the sizes of less than 50 nm, MnO nanorods with the sizes of 50–200 nm, and Mn3O4 nanoparticles with the sizes of 50–500 nm. In addition, the main phase of the fumes deposited on the vacuum chamber gradually changes to elemental Mn with an increase in the initial Mn content. The temperature and particle size are responsible for thermodynamic stability of Mn oxides at the nanoscale.

Rancang Bangun Prototype Mesin Pengering Gabah Otomatis Menggunakan Metode PID sebagai Kendali Temperatur

The value of rice grain content after harvest is quite high, around 20-23% in the dry season, and around 24-27% in the wet season. It was drying grain after harvest was processed by the conventional or manual method that carried out the grain drying in the sun. This method has several disadvantages, such as the dependence on the weather, requires a large area, and 54 hours for drying so that the grain becomes dry with a moisture content of 14.12%. From this problem, the researchers made a grain drying machine that could work automatically. The drying machine is made to solve the issues of conventional grain drying so that the machine was completed with a K type thermocouple temperature sensor and grain moisture content. Whereas the heating media uses a fire that is fueled with LPG gas, and then the heat from the fire has flowed into the furnace or grain drying chamber. The heating arrangement was made by regulating of flowing LPG gas to the nozzle through the opened and closed variable valve where the valve shaft was connected to the DC motor shaft. The application of the PID method also used in this drying machine, which has a purpose while controlling the drying temperature to match the Set Value (SV) or the desired temperature at 38oC. The grain moisture content value is considered to have dried up when the grain moisture content value is 14%. The PID method that is implanted into the ATmega16 microcontroller will give a signal to the motor driver circuit to regulate the direction of rotation of the DC motor connected to the opened and closed valve variable. PID method testing was done by trial error and has produced a steady-state error of 5.2% at S0056=38oC with constant values Kp=2, Ki=2, and Kd=10. Whereas for drying grain testing on harvested is done by selecting Ciherang grain with a moisture content of 20% and a weight of 3 kg. The grain drying process takes 30 minutes so that the value of the water content becomes 14% with a drying temperature of 38oC, so the grain drying rate on this machine is 0.17% per minute.

New approach of friction AlN ceramics metallization with the initial FEM verification

Although, the friction method is well known for metals surface modification, the novelty of the article is based on the new idea of ceramics surface treatment with metal. The paper describes AlN ceramic metallization process by titanium coating deposition, obtained in friction surfacing method, which has been developed by the authors. The friction energy is directly transformed into heat and delivered in a specified amount precisely to the joint being formed between the metallic layer and the ceramics substrate material. The stress and temperature fields (as factors promoting the formation of diffusion joints) induced in the joint during the metallization process were qualitatively determined with the finite element method analysis and these results were verified experimentally. Finally, obtained structures of the metallic coatings were investigated and the results are discussed in the paper. As a novelty it was found, that the conditions of frictional metallization can favour the formation of a coating-substrate bond based on diffusion phenomena and atomic bonds of the coating components with the components of the substrate, despite the fact that it happens for metal–ceramics pairs. This type of connection is usually associated with long-term heating/annealing in chamber furnaces, because for diffusion in a solid state the most effective factor is time and temperature. It was shown that other components of the chemical potential gradient, such as temperature gradient, gradient and stress level, load periodicity and configuration of pairs of elements with high chemical affinity may play an important role in friction metallization. As a result, the relatively short time of operation (friction) is compensated.

ПОДХОДЫ К ЧИСЛЕННОМУ ИССЛЕДОВАНИЮ ТОПОЧНЫХ КАМЕР С ЦИРКУЛИРУЮЩИМ КИПЯЩИМ СЛОЕМ

Актуальность исследования. В современных научных исследованиях вычислительный эксперимент является одним из наиболее продуктивных средств изучения комплекса задач, в которых результат зависит от одновременного проявления аэродинамики, теплообмена и горения. Численные расчеты при этом позволяют не только правильно интерпретировать физические явления, фиксируемые на экспериментальных установках, но нередко и дополнить существенно более дорогостоящий и трудоемкий физический или натурный эксперимент компьютерной симуляцией. В связи с этим актуальность проведения исследований, направленных на совершенствование методов численного анализа топочных процессов в котлах с циркулирующим кипящим слоем на основе компьютерного математического моделирования, является весьма высокой для обоснования основных проектно-конструкторских и технологических решений, принимаемых при создании котлов с циркулирующим кипящим слоем. Помимо практической значимости, такого рода исследование обладает высокой научной составляющей, поскольку в основе поставленной задачи лежат фундаментальные закономерности физико-химических процессов в циркулирующемкипящемслое. Цель: определение подходов и применимости численных алгоритмов с удовлетворительным уровнем детализации и сходимости для моделирования топочных процессов в котлах с циркулирующим кипящим слоем. Объекты: топка с циркулирующим кипящим слоем, оборудованная двумя вводами подачи топлива и инертных частиц на тыльной стене и десятью трубопроводами вторичного дутья на фронтовой стене в два яруса. Методы: математическое моделирование физико-химических процессов в топочной камере с циркулирующим кипящим слоем на основе Эйлеро-Эйлерова и Эйлеро–Лагранжева подходов с использованием RANS моделей.Записаны дифференциальные уравнения длясохранения массы, импульса, энергии и переноса частиц. Численное исследование проведено с использованием пакета прикладных программAnsysFluentv.12.1. Результаты. Определены начальные и граничные условия для численного моделирования процессов в топочной камере котельного агрегата с циркулирующим кипящим слоем при использовании Эйлеро-Эйлерова и Элеро–Лагранжева подходов.

Performance Analysis on Combustion and Heat Transfer of the Ship Power Plant

Study results on the supercharged boiler numerical simulation are on the boiler, convection tube bundle or the super-heater. These study subjects in a single model, and simplified the boundary condition to a certain extent. This paper takes the boiler as a whole research object. On the furnace chamber for combustion simulation, using the profile boundary information file boundary condition setting, faithfully transmitting boundary parameter spatial distribution. Followed by the simulation of heat transfer between the convection tube bundle and super-heater modules, we can get a real fluid flow and heat transfer condition, thus reacting to the complex heat transfer and flow inside of boiler, knowing the distribution of temperature, speed, pressure and other parameters. We can also see the change rule of the combustion and heat transfer processes in that supercharged boiler. Then we discuss the impact of the not uniform heat load on the convection heating surfaces, and preliminary analyzes the mechanism of combustion and heat transfer in supercharged boiler.

Shear capacity of indirectly loaded reinforced concrete beams under and after fire exposure

To investigate the shear capacity of indirectly loaded reinforced concrete beams under and after fire exposure, load tests were conducted on eight full-scale specimens exposed to fire testing in a furnace chamber, and the effects of additional transverse reinforcement in the junction region between the primary and secondary beams on the shear capacity, fire resistance, failure modes and deflection were analysed. The results indicate that the slopes of the diagonal cracks in post-fire tested reinforced concrete beams without additional transverse reinforcement were shallower than those of a similar reference beam not exposed to fire, and that the ultimate capacities of reinforced concrete beams with additional transverse reinforcement decreased obviously after fire exposure. However, beams with additional transverse reinforcement exhibited increased fire resistance times and reduced strains in their reinforcement, indicating the benefit of conservatively providing such reinforcement. The findings of this study are expected to provide a reference for the improved fire-resistant design of indirectly loaded beams.

Cyclone-Bed Furnaces: Experimental Studies and Thermal Design

Furnace processes occurring in laboratory setups, pilot commercial facilities, and small-capacity boilers of various sized equipped with cyclone-bed furnaces containing fixed and fluidized beds burning solid biofuels (wood pellets, straw pellets, sunflower husk pellets, peat pellets, wood waste, wood chips, milled peat, and crushed peat bricks) are investigated. The distribution features of temperature and gas concentrations (CO, CO2, H2, O2, CH4) in the combustion and secondary combustion chambers have been established in the course of experiments. With this information available, it becomes possible to determine the zones in which fuel actively reacts with the oxidant under the conditions of two-stage vortex combustion. Dependences of the carbon monoxide (CO) and nitrogen oxide (NOх) concentrations in the flue gases on the excess air ratio, bottom blast share (primary air), furnace power, and the combustion chamber’s outlet hole diameter are obtained. The furnace processes in cyclone-bed furnaces are numerically simulated using the standard k–e turbulence model and the Magnussen combustion model, and satisfactory agreement between the calculation and experimental results is shown. A semiempirical method for designing cyclone-bed furnaces has been developed, according to which their main geometrical and operating parameters are determined in two stages: a preliminary thermal design analysis is first carried out, after which the furnace process is numerically simulated. Based on extensive generalization of experimental data on the burning of solid biofuels in cyclone-bed furnaces having different diameters, the parameter М = 0.52, which appears in the well-known Gurvich formula for the thermal design of furnace chambers, has been determined. This parameter takes into account the temperature field structure and the heat transfer pattern over the furnace height, thus making it possible to use the standard method in carrying out thermal design computations of furnaces.

Three-dimensional thermal calculations of the radiation chamber of a cylindrical heating tube furnace

The paper briefly describes the method of thermal calculations of radiation chambers of tube furnaces on the basis of modelling interconnected processes taking place in the furnace by three-dimensional differential energy equations, the transfer of momentum components, mass concentrations of methane and air, continuity, a two-parameter model of turbulence and the equation of energy transfer by radiation. A software package using this method is applied to carry out numerical analysis of the spatial temperature distribution, the averaged values of velocities of the combustion products turbulent flow in the combustion chamber of a cylindrical heating tube furnace of the oil-processing industry. A furnace diagram with diffusion burners on the radiation chamber floor and differential equations describing physical processes taking place in the furnace are given. Methods for solution of the initial equations are described. The obtained distributions of the surface densities of heat fluxes to the coils along the chamber perimeter at different heights of the furnace are demonstrated. Graphs of the temperature change of the combustion products and the tubular reactor walls for different values of the angular coordinate are given.

Thermal calculation of the radiation chamber of an ethane pyrolysis furnace

Using our own application package that implements the differential method of thermal calculation of furnaces, we calculated the temperature fields in the radiation chamber and the distribution of heat fluxes along the tubular reactors in a ethane pyrolysis furnace. The interconnected combustion processes of fuel gas, the turbulent flow of combustion products, radiant-convective heat transfer are described by two-dimensional equations of transport and motion. Wall burners are installed in eight horizontal rows on both walls of the radiation chamber. The combustion products of fuel gas in the air leaving the nozzles 128 of the burner create complex fields of flow velocities and temperatures in the radiation chamber of the furnace. Heat fluxes to the reaction pipes are formed due to the radiations of flue gases, soot particles and hot lined surfaces of the walls of the combustion chamber.

Chemical and Electronic Sensitization Effects Promoted By Noble Metal Nanoparticles on Gas Sensors Based on SnO Nanobelts

IntroductionSemiconducting metal oxides (SMOx) are the most studied materials for gas sensing applications due to their outstanding capacity to detect flammable and toxic gases, and their low-cost processing and ease of handling. [1,2]Many strategies have been developed attempting to achieve materials with improved sensor performance, including surface functionalization. The most common SMOx surface functionalization species are noble metal nanoparticles (NPs) given the possibilities to present both chemical and electronic sensitization effects.[3]This work reports on the gas sensing response of pristine and Pt and Pd decorated stannous oxide nanobelts. The responses of devices to different analytes (H2, CO and NO2) were measured in dry air baseline atmosphere as function of the analyte concentration (1–1000 ppm) and temperature (150-350 °C). Method Stannous oxide nanobelts were synthesized by a carbothermal reduction method using a mixture of SnO2 powder (Sigma-Aldrich, 99.9% purity) and carbon black (Union Carbide, > 99% purity) in the molar ratio of 1.5:1 (SnO2:C) as starting material.[4] The nanoparticles (Pt and Pd) used to functionalize the surface of nanobelts were prepared by the polyol method.Samples were characterized by field-emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM) to study their morphology and crystalline structure.Suspensions of pristine and functionalized materials were deposited onto interdigitated platinum electrode arrays to perform the gas sensor measurements. The devices were placed in a temperature-controlled tubular furnace chamber, where the electric current was monitored under a constant applied voltage. Synthetic dry air was used as baseline and the analytes (NO2, H2 and CO) were introduced into the chamber using mass flow controllers. Gas sensor measurements were performed ranging from 150 °C to 350 °C. Results and Conclusions SEM and TEM results showed that obtained materials were nanobelts in the SnO phase. Moreover, functionalization with noble metal nanoparticles was successful, presenting disperse nanoparticles (< 15 nm) over nanobelts surface.About the gas sensing measurements, pristine devices are both sensitive and selective for nitrogen dioxide (NO2) molecules between 100 and 250 °C. In addition, both Pd- and Pt- functionalized devices present excellent selectivity to H2 at 300 and 350 °C. Moreover, Pt- functionalized device presented good selectivity for high concentrations of CO (>200 ppm) at low temperatures (100 and 150 °C). Then, results showed that noble metal decorated devices exhibited enhanced chemical sensitization, resulting in increased sensitivity upon exposure to reducing gases at different working temperatures. Differences in enhancement levels are attributed to strong electronic sensitization effects that are dependent on the respective Pt and Pd work functions and the unique SnO band structure, characterized by a small band gap (0.6 eV). Values showed that while Pt0 and Pt2+ promotes a high potential barrier with SnO nanobelts, Pd0 does not have this effect. Based on these findings, we propose an array based on pristine and NPs-functionalized SnO structures capable of detecting and distinguishing reducing and oxidizing gases. Furthermore, electronic sensitization mechanism is elucidated based on the band diagram of materials.Results presented here are important to engineer high performance sensor devices by selecting the better work function of nanoparticles, depending on the Fermi level of semiconductor.

System Development for Diffusion Bonding of Multiple Unit Tubes to Produce Long Tubular Tungsten Heavy Alloys

A diffusion bonding system to fabricate long tubular parts by joining of two- or more-unit tubes made of tungsten heavy alloys (THAs) is proposed and characterized in this study. The difficulty of powder processing of THA originates from the weak strength of the green compact and the high weight of the THA powders. The long tubular green compact is difficult to handle due to its weak structural integrity. Furthermore, gravity-induced slumping during liquid phase sintering induces dimensional distortion and degrades the mechanical performances. As a clue for solving these problems, the unit tubes are fabricated. However, the mass of green compacts for unit tubes is not sufficiently great as to cause problematic slumping; tubular unit tubes can be obtained without significant difficulty. Fabricated unit tubes are stacked in a furnace chamber and diffusion-bonded to produce a long tubular part having bond strength substantially equal to that of a monolithic tube. The proposed diffusion bonding system was well characterized and successfully applied to the industrial production line. The feasibility was also confirmed by investigating the bond quality, which can be assessed by metallographic microstructure and mechanical property.

Dependence of mechanical properties of mitral valve annuloplasty rings on annealing modes

Objective : to investigate dependence of the mechanical properties of mitral annuloplasty rings on heat annealing modes. Materials and methods . The study evaluates the nature of change in stress–strain curves under uniaxial compression of experimental samples processed at varying annealing temperature, duration and pressure. Results . It was noted that higher exposure, temperature, and lower pressure led to increased structural rigidity and strength for small strains. Moreover, the extent of influence of annealing temperature and duration was comparable. A 40% (500–700 °C) change in temperature altered the mechanical properties of the ring – 20% increase in strength. A similar change in heat treatment time (4.5–6.5 min) resulted in a 27% increase in the force required for a 15% compression. Conclusion . The experimental dependences presented in the work allow recommending main parameters for heat treatment mode: temperature range 600–700 °C, 10.5 minutes exposure time, and 0.1–0.5 atm air pressure in the furnace chamber.

Mathematical Model of a Heating Furnace Implemented with Volumetric Fuel Combustion

Heating flame furnaces are the main type of furnaces used for heating and heat treatment of metal products in metallurgy and mechanical engineering. In the working chamber of a modern heating furnace, there should be neither high-temperature nor stagnation zones. One of the methods used to provide such combustion conditions is the application of distributed (volumetric) combustion. Owing to this method, heating quality is ensured by creating a uniform temperature field and equivalent heat exchange conditions, regardless of the placement of the charge in the working chamber of the furnace. In this work, we numerically study the volumetric combustion and influences of small- and large-scale recirculation ratios of furnace gases, the influence of temperature fluctuation on the regenerator nozzle, and the working parameters at the starting phase and reverse.