Large-scale Furnace Research Articles

FINEX PCI fuel diversification for techno-economical operations: Impact of high-volatile coal agglomeration on combustion

Large-scale (volume > 2000 m3) blast furnaces (BFs) requiring expensive, high-grade coal are currently used in the iron and steel industry. High-volatile coal (HVC) must provide a substitute for high-grade coal to facilitate economical operations. This study determines the applicability of HVC and thermal coal within the fine particle extraction (FINEX) and conventional BF steelmaking processes using a drop-tube furnace. Furthermore, the characteristics of single- and blending-coal-carbon conversions are analyzed using unburned carbon (UBC). In the BF, an increase in agglomeration leads to an increase in UBC, where approximately 20 % agglomeration can be achieved. However, under FINEX conditions, due to the high oxygen concentration approximately 50 % agglomeration can be achieved. To determine the principle of the agglomeration phenomenon, a chemical-percolation-devolatilization model is used to analyze the amount of tar, light gas, and char generated during the devolatilization process. Using HVC achieves 89.7 % agglomeration which generates a 30 % tar volume during devolatilization. Tar has a significant effect on agglomeration and facilitates bridging, causing agglomeration into a large particle as identified from the structural agglomeration of a scanning electron microscopy image. This phenomenon affects raceway formation and the combustion stability of pulverized coal injections.

Numerical simulation and structural optimization of the diffusion furnace for crystal silicon solar cells

The diffusion furnace is an important device for crystalline silicon solar cell production. Given the rapid evolution of solar cell technology, large-scale, high-efficiency and mass-produced diffusion furnaces are required by the market. This puts forward higher requirements for the diffusion furnaces. In this study, a large-scale 3D model is established and validated by measured data in practical diffusion furnace. Its internal temperature, velocity and gas concentration fields are analyzed. The silicon wafer temperatures are found to be high at the top but low at the bottom. The temperature uniformity at both ends of silicon wafer groups is poor. To solve these problems, three structural optimization methods, namely the inlet pipe optimization, adding uniform-flow plates and the quartz boat optimization, are proposed and analyzed. The average mass fraction in the diffusion furnace is improved by 6.311% using the two-tube forked intake pipe. The uniform flow plates with evenly distributed pores on the lower half effectively improve the gas concentration uniformity on silicon wafer surfaces. The optimized quartz boat can improve the temperature uniformity of silicon wafers, though its deformation slightly increases by 0.338%. The silicon wafer temperature differences after quartz boat optimization are 13.77–50.27% smaller than those before optimization, which are conducive to reducing the thermal stress, the risk of thermal damage and the failure during manufacture and utilization of silicon wafers. Results in this study give guidelines for design and utilization of crystal silicon solar cell diffusion furnaces, some of which have been successfully used in Trina Solar Energy Co., China.

Fire Performance of FRCM-Confined RC Columns: Experimental Investigation and Parametric Analysis

This study presents an experimental investigation of the fire response of six columns strengthened with polyparaphenylene benzobisoxazole (PBO) FRCM system, and tested in a large-scale furnace following ASTM E119 standards. The parameters investigated included the number of PBO-FRCM layers and the presence of a fireproofing insulation layer. Test results highlighted the effectiveness of PBO-FRCM in insulating the column, with the strengthened column showing a substantial 31.9% reduction in temperature readings at the concrete surface compared to its unstrengthened counterpart. Furthermore, the presence of Sikacrete 213F fireproofing system reduced temperature readings within the column's section by an average of 65%. Based on the experimental results, a parametric numerical study were developed and verified using ABAQUS software. The parameters studied included the number of PBO-FRCM layers (0, 1, and 2 layers), the presence of a 30 mm thick insulation layer, and the axial preloading taken as 40, 60, and 75% of the ultimate column's capacity. The model accurately predicted the temperature readings across the columns. Strengthening the columns with PBO-FRCM significantly increased their resistance during fire, doubling fire-resistance duration with one layer. Adding fireproof insulation led to significant increase in load resistance duration. The percentage drop in temperature after 1 hour of fire exposure was around 70% at the FRCM surface for the insulated column strengthened with one layer of FRCM. Higher preload percentages reduced both the fire-resistance duration and ductility of the columns. For the group of columns strengthened with one layer, increasing the preloading percentage to 60% and 75% resulted in decreases in the fire-resistance duration of 35% and 73%, respectively.

Furnace-height FGR location impact of a cascade-arch-firing configuration in ameliorating low-NOx combustion and eliminating hopper overheating for a large-scale arch-fired furnace

This study analyses an alternative to the existing multiple-injection and multiple-staging combustion technique (MIMSCT) of large-scale arch-fired furnaces. The alternative approach is a cascade-arch-firing, low-NOx, and high-efficiency configuration (CLHC) with flue gas recirculation (FGR). The research is necessary as typical 600 MWe large-scale arch-fired furnaces produce high concentrations of NOx and have a high risk of overheating in their hoppers when firing low-volatile coals. Three furnace-height FGR locations were considered in descending order (i.e., FGR through (i) primary burners to mitigate fuel-NO (FGR-PB), (ii) tertiary air to restrain thermal-NO (FGR-TA), and (iii) auxiliary burners to reduce NO (FGR-AB)). Industrial-scale measurements and simulations were conducted in the existing MIMSCT furnace (which was used to verify simulations and compare with the subsequent CLHC furnace results), followed by numerical investigations of the CLHC furnace at the three FGR-locations. The FGR’s NO inhibition in the upstream zone decreased in the following order: FGR-PB > FGR-TA > FGR-AB. Initial combustion and NO generation in the reburning stage was most intense in the FGR-TA configuration (producing the highest NO amounts) whereas the FGR-AB configuration contributed the lowest amounts. As the FGR locations descended, burnout loss dropped a little, while NOx production was initially elevated and then descended. The FGR-PB was optimal among the three options, with a low NOx output of 604 mg/m3 (O2 = 6 %) and combustible level in fly ash of about 5 %. Compared to the MIMSCT, the CLHC not only enhanced the low-NOx environment and shortened the flame penetration but also improved combustion intensity and extended the overfire air penetration. This sharply reduced NOx without affecting burnout nor lowering apparent hopper temperatures. The above results demonstrate that a staged FGR consisting of primary FGR-PB and supplementary FGR-AB, is a promising solution to lower NOx while retaining high furnace burnout levels.

Confirming the efficacy of a new arch-firing solution in safely strengthening low-NOx combustion within a large-scale furnace: Impact of the flue gas recirculation position in burners

To address the persistently high NO x production and the heightened overheating risk in the hopper of a 600-MWe, deep-air-staging, arch-fired boiler furnace (i.e., the reference furnace), a solution was devised with a staged arch-firing framework (SAF) and flue gas recirculation (FGR). This required establishing an appropriate position for the burner-FGR and confirming the viability of the SAF for the furnace. Comprehensive industrial-scale physical tests and computer simulations were conducted using the reference furnace. Subsequently, the furnace with SAF was examined with FGR introduced sequentially, first using a fuel-rich mixture, then using an inner secondary-air flow, and finally using an outer secondary-air flow (i.e., denoted in turn as FGR-FR, FGR-IS, and FGR-OS). Given this FGR-location order, the FGR’s functions about combustion degradation and NO inhibition weakened, resulting in increased NO x emissions and continuously decreasing burnout loss. Considering the satisfactory burnout levels across all three configurations, the FGR-FR configuration demonstrated the best reduction in NO x emissions, achieving NO x output of about 600 mg/m3 (O2 = 6%) and an unburnt combustible rate in fly ash of about 5%. Comparing the conditions before and after implementing the SAF indicated that the SAF enhanced combustion intensity and improved the utilisation of overfire air and hopper air, resulting in a further 33.3% reduction in NO x emissions without compromising burnout efficiency. Additionally, the SAF effectively mitigated the overheating risk in the hopper by significantly lowering local temperature levels by 400 K.

Assessing the impact of wet and dry flue gas recycling on heat transfer in oxygen-fired circulating fluidized bed furnaces

Oxygen-driven circulating fluidized bed combustion (oxy-CFB) has been suggested as a potential technique for facilitating carbon capture in large-scale power generation. Precise modeling of radiative heat transfer is vital for forecasting the thermal performance of such processes. This research examines the impact of wet and dry flue gas recycling on the thermal behavior of a large-scale oxy-CFB furnace, utilizing a combined modeling strategy that merges a three-dimensional furnace process model with a thermal radiation solver. The semi-empirical furnace model operates in steady-state conditions, accounting for fluid dynamics, reactions, and heat transfer phenomena. The radiation solver, based on the zone method, employs novel correlations for radiative heat exchange between optically thick zones. The radiation solver employs a weighted sum of the gray gases model, developed specifically for oxy-combustion, and geometric optics to determine the radiative characteristics of combustion gases and particles, respectively.This research covers various process conditions and boiler loads to evaluate the influence of wet versus dry flue gas recycling on heat transfer and temperature profiles. Model results were successfully compared against small-scale oxygen-fired CFB tests and large-scale measurements in a supercritical air-fired CFB. Utilizing an external radiation solver allows for a more precise representation of radiative heat transfer and the influence of varying process conditions. The insights from this research can aid in the design of large-scale oxy-CFB facilities, and the demonstrated modeling approach can be employed for additional model development, such as integrating the external radiation solver with other modeling tools.

Improved operation of a large-scale blast furnace using a hybrid dynamic model based optimizing control scheme

In the steel industry, the blast furnace (BF) is a core piece of equipment along the route from iron ore to steel, with the largest energy consumption and CO2 emissions. The stable, efficient, and economically viable thermal control of blast furnaces is still a challenging task, and fully automatic solutions are not applied industrially. The process exhibits multi-phase and multi-scale physio-chemical phenomena, in the presence of fast and very slow dynamics with latency periods of 6-8 h. Direct online measurements of key inner variables are missing, and unknown disturbances are strongly influencing the process; in particular, the quality of solid raw materials that are fed at the top of the furnace. Partial automation is the state-of-the-art strategy in the operation and control of industrial blast furnaces, and the experience and the dedication of the operators have a direct impact on the stability and efficiency of the operation. Model-based optimizing control schemes, which can be deployed either in closed-loop or as a guidance system to achieve a smooth, efficient, and reliable operation of blast furnaces, are promising. In this work, we propose a hybrid dynamic model based optimizing control scheme for the stable, energetically efficient, and economically optimal thermal control of blast furnaces. The underlying optimization problem is formulated as a combined tracking and performance optimizing control problem, where the goal is the tight control of the hot metal silicon content ([Si]) and the slag basicity (SB), while simultaneously maximizing the CO-efficiency of the furnace. These two variables are key product quality indices, and [Si] is an indicator of the internal thermal state of the BF process. Simulation results using real operational data of a large-scale industrial blast furnace are presented to demonstrate the potential of the approach for an improved operation of blast furnaces.

Synthesis mechanism of AlN–SiC solid solution reinforced Al2O3 composite by two-step nitriding of Al–Si3N4–Al2O3 compact at 1500 °C

The in-situ controllable synthesis of AlN–SiC solid solution reinforcement in large-sized Al–Si3N4–Al2O3 composite refractory by two-steps nitriding sintering was examined. In the first step, a dynamic Al@AlN structure was constructed in the composite by pre-nitriding at 580 °C. During the subsequent sintering process, it cracked above ∼900 °C, and micronized Al cluster (mixture of droplets and vapor) was extracted out gradually. As a result, multiple AlN mesophases were formed through different reaction paths, including i) initial AlN shell formed by solid Al with N2, ii) reaction of Al cluster with N2, and iii) reaction of Al cluster with Si3N4 from 900 °C to 1500 °C. The Si3N4 precursor serves as both a solid nitrogen source and an active Si source, and the controllable reaction between Al and Si3N4 leading to uniformly distributed AlN and Si mesophases. AlN–SiC solid solution is significantly formed when liquid Si appears. The shell, granule and whisker SiC–AlN solid solution were observed mainly depending on the dynamic AlN mesophase. The SiC–AlN solid solution reinforced Al2O3 materials is a novel promising refractory for large-scale blast furnace lining.

Thermoelectric Generator Using Low-Cost Thermoelectric Modules for Low-Temperature Waste Heat Recovery

One of the most significant problems in industrial processes is the loss of energy according to the sort of heat. Thermoelectrics are a promising alternative to recovering this type of thermal energy, as they can convert heat into electricity, improving the industrial efficiency of the process. This article presents the characteristics of low-cost thermoelectric modules typically used for generation (SP1848-27145SA (TEG-GEN)) and refrigeration (TEC1-12706 (TEC-REF)), both utilized in this research for heat recovery. The modules were evaluated against various configurations, source distances, and distributed systems in order to determine optimal recovery conditions. The experiments were conducted both at the laboratory level and in a large-scale furnace of the traditional ceramics industry, and they revealed that even refrigeration modules are suitable for energy recovery, particularly in developing countries, whereas other generators are more expensive and difficult to obtain. These thermoelectric generators were tested for low-temperature heat recovery in regular furnaces, and the results are to be implemented elsewhere. Results show that even the thermoelectric refrigeration modules can be a solution for heat recovery in many heat sources, which would be particularly strategic for developing countries.

Experimental research of a small-scale industrial furnace with regenerative disc-flame burners

Regenerative combustion technology has many advantages such as fuel saving, high combustion efficiency and low emission, and it has been widely used for large-scale furnaces. However, when regenerative combustion technology is adopted for small-scale furnaces, many technical problems occur. In this paper, a small-scale regenerative furnace with heat load of 70–80 kW and primary air coefficient of 1.00–1.60 was designed. It was found that the flame shifts from bright pale blue with faint rotating streamlines to yellowish transparent without apparent streamlines and to bright and transparent eventually. When main burners work stably, the temperature inside the furnace raises rapidly at first, and then the temperature increases steadily and fluctuates periodically. The highest temperature in the furnace can reach around 1300 °C. As the reversing time increases, the temperature fluctuation becomes more dramatically and the highest temperature is higher. NOx concentrations at all measurement points are below 50 ppm. Heat transfer efficiencies of each heat retainer show an increasing trend with the rise of the number of reversions. As reversing time increases, the heat transfer efficiency shows a decreasing trend.

Design and optimization of large-scale single-crystal furnaces asymmetric hooked magnetic fields

The solar photovoltaic power generation industry and large-scale integrated circuit industry put forward higher requirements for the size and quality of monocrystalline silicon. However, there are some problems in the production of large-diameter and high-quality monocrystalline silicon, such as uneven crucible thermal field and strong melt convection, which affect the quality of monocrystalline silicon. Therefore, by adopting the finite element 2D modeling method, this paper established the asymmetric hook magnetic field model of the 40-inch crucible. Hence the key magnetic field parameters affecting the growth of a single crystal were determined by controlling the melt convection in the crucible. Meanwhile, through finite element static magnetic field simulations, the effect of the magnetic field at the crucible wall was analyzed by adding the upper and lower guide rings of the magnetic shield structure, the magnetic shield structure with intermediate permeability ring, and the coil parameters. In addition, the parameters of the asymmetric hooked magnetic field structure were also optimized based on the simulation data. On the above basis, a numerical simulation analysis of the key parameters of the magnetic field was carried out. The simulation results show that the optimized asymmetric hook magnetic field structure can effectively control the melt convection in the crucible. In addition, the magnetic field strength at the crucible wall can meet the target of restraining convection by a magnetic field. Hence, it provides a certain reference value for the design of a large-scale single crystal furnace magnetic field.

The finite element method for evaluating the fire behavior of steel structures

PurposeThe purpose of this study is to contribute toward providing the main aspects of numerical modeling the fire behavior of steel structures with finite elements (FEs). The application of the method is presented for a characteristic case study comprising the series of large-scale fire door tests performed at the Danish Institute of Fire and Security Technology.Design/methodology/approachFollowing a general overview of current practices in structural fire engineering, the FE method is used to simulate the large-scale furnace tests on steel doors with thermal insulation exposed to standard fire.FindingsThe FE model is compared with the fire test results, achieving good agreement in terms of developed temperatures and deformations.Originality/valueThe numerical methodology and recommended practices for modeling the fire behavior of steel structures are presented, which can be used in support of performance-based fire design standards.

Investigation of the Reaction Kinetics of a Sinter-Reduction Process in the Thermal Reserve Zone of a Blast Furnace Using a Modified Sectioning Method

With the development of large-scale and high-performing blast furnaces, it is necessary to extensively study the reaction characteristics and related kinetic parameters of sinters in their heat reserve area. Under reducing atmosphere conditions, the reduction of iron oxide in sinter is closely related to the gasification reaction of coke. Based on a simulation experiment, the transition point from chemical reactions to diffusion and the related kinetic parameters were determined through a sectioning method. The results showed that increasing the proportion of low-grade coke increased the chemical-reaction rate, but it slightly decreased the mass-transfer and diffusion rates. An increase in the coke particle size increased the chemical-reaction, mass-transfer, and diffusion rates. However, an increase in the CO2 volume fraction in gas reduced the chemical-reaction, diffusion, and mass-transfer rates. The mixing ratio of coke and sinters increased the chemical-reaction rate, but it decreased the mass-transfer and diffusion rates. The rate constant of the chemical reactions in the early stage was three orders of magnitude higher than that of the diffusion and mass-transfer coefficients, and the fitting degree was obviously better than that of the molecular diffusion in the later stage. Based on the thermodynamics of irreversible processes, the interference of the chemical reactions with the diffusion and mass transfer in the near-equilibrium region was tentatively established, the method of controlling coke diffusion and mass transfer in the later reaction stage was given and related kinetic parameters were corrected, and further improvement of the modified sectioning method was completed.

Nonstationary Process Monitoring for Blast Furnaces Based on Consistent Trend Feature Analysis

Blast furnaces are the most crucial equipment in ironmaking processes. Stable operation of the blast furnace is a prerequisite for personnel safety and production efficiency. Therefore, early detection of abnormalities in blast furnaces is an important task for ironmaking processes. However, owing to the large fluctuations in the quality of raw materials, dynamic operating conditions, as well as the impact of the hot blast stoves switches, the measurements of blast furnace show severe nonstationary characteristics. All these factors make monitoring the blast furnace a challenging task. In this article, a nonstationary process monitoring method called consistent trend feature analysis (CTFA) is proposed, which can extract the trend-related features and discard perturbations in process data. The directions and amplitudes of the extracted trends are used for abnormality detection, and a local-learning-based method is proposed for determining a time-varying control limit. The detection performance of the proposed method is analyzed, with a sufficient condition and a necessary condition for the detectability given. The effectiveness of the proposed method is validated by the practical data collected from a large-scale blast furnace located in Liuzhou, China.

A hybrid dynamic model for the prediction of molten iron and slag quality indices of a large-scale blast furnace

The stable, economically optimal, and environmental-friendly operation of blast furnaces is still a challenge. Blast furnaces consume huge amounts of energy and are among the biggest sources of CO2 in the metal industry. The operation of industrial blast furnaces is challenging because of their sheer size, multi-phase and multi-scale physics and chemistry, slow dynamics with response times of 8 hours and more, and the lack of direct measurements of most of the important inner variables. Model-based schemes are prime candidates for providing the missing information and improving the operation. However, only recently, such schemes have been applied successfully, and there is still a lot of room for improvements. The spatial extension, the lack of precise mechanistic knowledge about the chemical and physical phenomena, and the presence of unmeasured disturbances make the application of first-principle models to process operations extremely challenging. In this work, a hybrid dynamic model is developed for the prediction of the hot metal silicon content and the slag basicity in the blast furnace process. These two variables are the key indicators of the internal process conditions, and the ultimate goal of our work is to control them by a model-based scheme. The core relationships between the process variables are imposed by a first-principles-based steady-state model, and a parallel data-based model represents the process dynamics and compensates for the deficiencies of the mechanistic model. Validation results for real plant measurements of a world-scale blast furnace show that the hybrid model is more accurate than the rigorous model and a stand-alone data-based model in long-term predictions of the dynamic behavior of the process.

Characteristics and combustion kinetics of fuel pellets composed of waste of polyethylene terephthalate and biomass

BACKGROUND AND OBJECTIVES: The needs of fuel pellets from varied feed stocks have opened up opportunities and challenges for pellets production from non-woody biomass. Wastes of plastic recycling and wood sawing contained a high potential for energy source and suited for pelletizing as a solid fuel. METHODS: The characteristics and combustion kinetics of fuel pellets made using a mixture of waste of polyethylene terephthalate and biomass (Tectona grandis Linn.f) with a polyethylene terephthalate to biomass ratio of 9:1. The investigation covered physico-chemical properties and their functional group analysis, heavy metal concentration and ionic leachability testing, and ash analysis. In this context, thermogravimetric analysis was used in an atmosphere of oxygen gas, over a temperature range of 50-800 °C and at different heating rates. The work ends with discussion of the kinetics study via three comparative evaluations and the feasibility of fuel pellets for energy utilization. FINDINGS: Pelletizing with this ratio (9:1) was present the durability of PET/biomass pellets, a uniform dimension, ease handling, storage, and transportation common as woody pellets. Some technical challenges such as low moisture content and high volatile matter content were feedstock dependent. The major characteristics were a combination of those from both the constituent materials. Functional groups of the pellets were contributed by terephthalate and lignocellulose. The addition of a small amount of biomass in pellets could improve their thermal decomposition behavior. The properties of the polyethylene terephthalate/biomass pellets indicated that were fit for combustion with a high heating value equal to 19.20 MJ/kg. Heavy metals and ionic contaminants were below the maximum limits of the standards because of the cleanliness of the raw materials. However, the minor effects of earth materials and a caustic soda detergent were resulted in the alteration of residue chemicals. The pellets had lower ignition, devolatilization, and burnout temperatures than the original polyethylene terephthalate waste; likewise, the peak and burnout temperatures shifted to a lower zone. The activation energy values obtained using the Kissinger-Akahira-Sunose, Ozawa-Flynn-Wall, and Starink models were similar and in the range 142–146 kJ/mol. CONCLUSION: These findings may provide crucial information on fuel pellets from blended polyethylene terephthalate/biomass to assist the design and operation of a co-combustion system with traditional solid fuels. Such modifications of fuel pellets suggest the possibility of operating in large-scale furnace applications and can further be upgraded to other fuels production via modern bioenergy conversion processes.

Model and application of hearth activity in a commercial blast furnace

ABSTRACT With the development of a large-scale blast furnace, hearth activity has an important impact on the longevity and efficiency. Based on the analysis of practical example of ShaSteel No. 3 blast furnace, the new hearth activity model was proposed and verified, namely, the slag-iron flow resistance coefficient. Besides, in the model, the prediction of the coke particle size in the hearth was used to predict the hearth activity. Furthermore, the slag-iron properties and coke properties were analysed to the influence degree on the resistance coefficient. The model has been applied to the hearth of ShaSteel No. 3 blast furnace, and it can timely respond to the internal state of hearth. Finally, the methods to activate hearth activity were explained, which not only has application value but also provides theoretical support for the evaluation of hearth activity in actual production.

Numerical Prediction and Experimental Validation of the Low-temperature Oxidation Characteristics of Coal in a Large-scale Furnace in an Adiabatic Environment

ABSTRACT It is of great significance to study the characteristics of low-temperature oxidation of coal in an adiabatic environment for the prediction and control of coal spontaneous combustion. Coal spontaneous combustion experimentation can better simulate the field conditions and reflect and test the actual process underlying the spontaneous combustion of coal. Numerical simulation methods can provide a systematic solution for research on the dynamic evolution process of coal spontaneous combustion. In this study, a large-scale coal spontaneous combustion test bench was employed to test the oxidation heating characteristics and gas generation laws of Huangling coal samples from 303–443 K, revealing the spatiotemporal evolution characteristics of the gas concentration and temperature fields. Based on the theory of computational fluid dynamics (CFD), a mathematical model of the spontaneous combustion of coal in the adiabatic state is therefore constructed. The evolution law and distribution characteristics of the temperature and gas concentration fields of coal in the experimental furnace are simulated by Fluent. The results indicate that the position of the highest coal temperature in the experimental furnace mainly changed along the central axis and gradually moved down toward the air inlet as the coal temperature continued to rise. Above the critical temperature (353 K), the high-temperature point mobility was high, and only one-tenth of the ignition period could be utilized to travel along with more than one-third of the original distance from the intake side. In the furnace, O2, CO, and CO2 were distributed in the upper and lower layers at different concentration values. The concentration of O2 gradually decreased from the inlet side along the gas flow direction, but the concentrations of CO and CO2 demonstrated the opposite behavior. When the temperature exceeded 120°C, the consumption of O2 and the production of CO and CO2 gases were mainly distributed in the furnace body below 0.65 m. The simulation results are in line satisfactorily with the experimental results. This study provides theoretical support for field index gas and three zone division. The development of the model can improve the existing theory of coal spontaneous combustion and find a more systematic and reasonable criterion for judging coal spontaneous combustion.

Influence of turbulence-radiation interaction on radiative heat transfer to furnace wall and temperature distribution in large-scale industrial furnaces enveloping hydrocarbon flame

Influence of turbulence-radiation interaction on radiative heat transfer to furnace wall and temperature distribution in large-scale industrial furnaces enveloping hydrocarbon flame

Status and Characteristics of Ferrosilicon Industry in China

Currently, Chinese ferrosilicon industry shows characteristics including highly concentrated industrial regions, graded utilization of materials, large-scale submerged arc furnace, and application of automation equipment. Chinese ferrosilicon industry is highly concentrated in five major regions, where mineral and electric power resources are fully exploited to develop the coal-electricity-metallurgy and coal-coke-gas-electricity--metallurgy-magnesium industrial chains. Production relies on both the silica resources of Helan mountain and Qilian Mountain, and the unique semi coke with particle size of 5-18mm produced from Jurassic sticky coal in Shenfu region. A series of different characterization methods are used to achieve the graded utilization of materials, and the smelting power consumption could be optimized to 7200-7300kWh per ton of FeSi75. China encourages and support large-scale ferrosilicon furnaces, the load of new-built submerged arc furnace in the country are around 33-40MW, and the largest furnace reaches 63MW. Erdos as the biggest ferrosilicon producer in the world, has a capacity of more than 1 million tons per year. The load of its largest furnace is 50MW. Erdos is committed to the development of full-process automation for ferrosilicon production, which covers raw material storage and transportation, batching, distribution, electrode operation, charge-mix surface treatment, furnace discharge, casting and product crushing. For instance, the use of a self-developed automatic rotary feeder reduced the smelting energy consumption by optimizing the structure of charge-mix layer. The application of the automatic tapping machine allows robots to replace manpower in key and hazardous positions. This paper deeply analyzes the ferrosilicon industry characteristics in China and provides reference for the development of the ferrosilicon industry