Furnace Wall Research Articles

The Coal Dust Combustion Scheme for an Invert Furnace of an A-USC M-Shaped Boiler

The M-shaped boiler construction for the advanced ultrasupercritical steam parameters (A-USC) is proposed in this work. The boiler was designed to operate in a 500 MW unit on low volatile hard coal. This design allows reducing the pipelines length of the high cost steam pipelines made of nickel alloys. A downstream (invert) furnace is offered for this boiler type. The coal dust burning scheme design using the direct-flow burners and nozzles in a system of vertical and horizontal tangential torches and the solid ash removal are proposed. This approach was extensively used earlier on standard shaped boilers, and it was upgraded now for an invert furnace. The goals are achieved by conducting research on the physical furnace model and thermal furnace processes numerical simulation by computational fluid dynamics software. The most significant research results were as follows: the oxidizer stage supply was performed along the torch length and furnace height; the dynamic jet pressure on the furnace walls was excluded; a high degree of coal burnout was ensured due to the vortex furnace aerodynamics implementation; the uniform furnace section filling with air jets was performed; turbulent jets ejection was significantly higher than that for a flat submerged jet; chemical underburning loss did not exceed 0.1%; and unburned carbon loss was 0.8%. The carbon monoxide concentration at the furnace outlet in terms of air excess ratio equal to α=1.4 was 226 mg/nm3 . The nitrogen oxides concentration in the flue gases (normalized) was 424 mg/nm3 . The results significance obtained during the research is efficient solid fuel use with high technical and economic boiler performance.

Cell and dendrite growth of tungsten by atmospheric pressure chemical vapor deposition

In this study, tungsten coatings are deposited at 300–610 °C from WF6 and H2 by atmospheric pressure chemical vapor deposition (APCVD). Tungsten powders adheres to the furnace walls (cold wall furnace) in every deposition, regardless of whether the coating is dense or not. These tungsten powders are proved to be produced by homogeneous reactions in gas phase near the substrate and adheres to the furnace inner wall as they move with the fluid. The presence of tungsten powders when depositing dense tungsten coatings indicates that the homogeneous reactions contribute to the growth of dense tungsten coatings; with this premise, the kinetics, structure and growth mode of tungsten coatings in APCVD system are discussed. Activation energy of 28.7 and 61.9 kJ/mol corresponded to rate-limiting steps of the diffusion of the tungsten atoms in gas phase, and the dissociation of H2. The<100>orientated columnar grains along the growth direction (GD) are main-branches. Not all but majority of the small grains intercalated between the columnar grains orient in the direction close to<111>along the GD, and these small grains are proved to be parts of second-branches. In the early stage of deposition, the<100>orientated grains compete with each other due to the growth of the cell tips in width. Raised areas are found on the surfaces of pyramids, and the microstructure of the growth interface shows that flat interface is prone to curved when there are more favorable growth conditions ahead. These results reveal that homogeneous reactions lead to the cell and dendrite growth mode of tungsten coatings in APCVD system.

Forsterite refractory brick produced by talc and magnesite from Thailand

This research focuses on refractory material synthesized from precursors of talc and magnesite in Thailand. They were mixed at a molar ratio of 1:5 with mechanical activation at 5 h and calcined at 1300 °C for 1 h to create forsterite. The resulting forsterite crystals were round with less than 1-μm particle size. Synthetic forsterite refractory was formed into refractory bricks and studied at various sintering temperatures of 1200, 1300, and 1400 °C with a dwell time of 2 h. The characteristics and properties of refractory samples were tested in physical properties, cold crushing strength, thermal conductivity, thermal shock, and corrosion resistance from various substances. The results showed that increasing the sintering temperature increases the physical properties and cold crushing strength values. Also, the sintering temperature increases will increase thermal conductivity. The best condition of forsterite refractory brick sintering was 1400 °C for 2 h (FB-14), which showed the following desirable properties: firing shrinkage of 18%, bulk density of 3.03 g/cm3, the apparent density of 3.26 g/cm3, both apparent porous and water absorption values of zero, and cold crushing strength of 72.18 MPa. The FB-14 brick has excellent resistance to corrosion and penetration from lead silicate frit and copper slag. There was minor weight loss from the corrosion of the chemical solutions used in sodium hexametaphosphate production, whereby weight loss will begin on the 18th cycle. Consequently, the FB-14 brick can be used for blast furnace walls to slow down corrosion, which will allow the blast furnace to have a longer life cycle.

Development and heat transfer analysis of thermoelectric self‐powered fuel‐fired residential boiler

AbstractSolid‐state thermoelectric (TE) devices offer many interesting features compared with other methods of generation, such as no moving parts, high reliability, low maintenance, and straightforward integration with other heating equipment. In this study, a thermoelectric assembly was integrated into a residential heating boiler to convert a portion of combustion heat to electricity while meeting space and/or water heating needs. A prototype was developed, in which recently developed thermoelectric modules were incorporated into a gas‐fired boiler. The electricity generated by the thermoelectric assembly would be sufficient to power the electrical auxiliary components of the heating system. In this way, the heating system could operate entirely on fuel combustion and provide the consumer with heating system reliability and a reduction in power consumption. A model for the thermoelectric conversion system was established and the thermal resistance analysis was carried out to show the influence of heat transfer coefficients and other parameters on power output and efficiency, and thus improve the system design. In this study, the single‐module integrated assembly can produce a 22.5 W power output. However, each module of the four‐/eight‐module integrated assembly can only generate a power output of 7.85/9.175 W on average. The performance of a single module in a multimodule assembly is worse than that of a single module assembly. The number of modules placed on the furnace wall is not as many as possible but has an optimal value. In this experimental environment, the assembly of eight modules is the optimal choice. Furthermore, it is found that enhancing combustion‐side heat transfer capacity is an effective way to promote system performance. The power output of the assembly composed of four modules will increase by 70% from 7.85 to 13.5 W due to the installation of the fin on the hot end.

Transient simulation and exergy analysis of a D-type steam boiler with natural circulation during cold start: A case study

• Implementing of 3D mathematical model for D-Type boiler furnace. • Determining the natural circulation direction for each wall of furnace in the start. • The model results compare with experimental data of a D-Type boiler. • The sensitivity analysis on the initial water level of the drum is performed. It is necessary to utilize an accurate control system in D-type boilers under transient loading. In this paper, a saturated D-Type boiler has been modeled and studied under cold start condition. This type of boiler has two kinds of heat transfer surfaces which are radiative zone (RZ) and convective zone (CZ). Since the furnace shape according to the gas path is not symmetric, the RZ section has been modeled via 3D mesh, and the CZ section has been modeled via the zoning method. The presence of D-shaped tubes in the furnace and different heat absorption of other tubes forced the model to have consisted of four circulation circuits of water in RZ and CZ. According to cold start conditions, inverse flow can occur in circulation circuits which this phenomenon has been studied in this paper. The methodology was included: simultaneous modeling of flue gas side and water side via detail modeling of circulation circuits with exergy analysis, and asymmetric 3D modeling of furnace via mathematical models considering cold start constraints. The comparison of model data against experimental data has shown a maximum deviation of 8.6% for drum pressure during start-up. Also, a sensitivity analysis on the initial water level of the drum in cold-start conditions has been performed by increasing from 200 to 500 and 800 mm; and the results indicated a 4.2% and 10.8%, increase in fuel consumption, respectively. Moreover, the boiler's exergy efficiency reaches a maximum of 60% during cold start-up and declines to 38.2% in steady-state conditions.

Numerical Study of Non-Premixed Combustion Characteristics on Supplementary Firing of HRSG

&lt;p dir="ltr"&gt;&lt;span&gt;Computational fluid dynamics (CFD) is a simulation model to provide complex processes in the industry that has been widely used to investigate industrial-scale combustion phenomena. Supplementary firing is used to increase steam production. The non-premixed combustion is a type of supplementary firing. Supplementary firing has seven burners arranged vertically. Supplementary firing uses exhaust steam from a gas turbine to ignite the air. This research investigates the combustion characteristics of flame length and exhaust gas emission at burners. The viscous model was observed by using non-premixed modeling. While the absorption of radiation in the combustion residual gas was observed by using the weight sum-gray gases model (WSGGM). This study used the realizable &lt;/span&gt;&lt;span&gt;k-ε&lt;/span&gt;&lt;span&gt; model and tetrahedron meshing algorithm to approach the turbulent characteristics. The total nodes and the orthogonal mesh quality in the meshing steps are 1,334,359 and 0.86, respectively. The modeling results show that burners-1 and 7 have longer flame compared to other burners. The combustion exhaust gas has height contents of CO&lt;/span&gt;&lt;span&gt;&lt;span&gt;2&lt;/span&gt;&lt;/span&gt;&lt;span&gt; and H&lt;/span&gt;&lt;span&gt;&lt;span&gt;2&lt;/span&gt;&lt;/span&gt;&lt;span&gt;O. The velocity near the furnace wall is lower than the center of the furnace, but the pressure is higher. This phenomenon is dominantly influenced by the thermal boundary layer.&lt;/span&gt;&lt;/p&gt;&lt;div&gt;&lt;span&gt;&lt;br /&gt;&lt;/span&gt;&lt;/div&gt;

Reaction zone characteristics, thermal performance and NOx/N2O emissions analyses of ammonia MILD combustion

Pure ammonia MILD combustion is studied numerically in a furnace. The effects of furnace wall temperature and dilution of inlet air with nitrogen on the characteristics of reaction zone (RZ), temperature distribution and exhaust emissions are investigated. The results show that lowering the furnace wall temperature and adding diluent to the inlet air, result in expansion of the RZ, reduction of fuel and oxidizer consumption rates, lower Damkohler, increased turbulent Reynolds and more similar RZ properties to the distributed combustion regime in the combustion regimes diagram. At a lower concentration of oxygen in the oxidizer, a higher threshold wall temperature is required for stable MILD combustion. Reducing the wall temperature and oxygen mole fraction in the oxidizer, increases the uniformity of temperature distribution. Analysis of exhaust emissions shows that reducing wall temperature and oxygen level in the oxidizer stream can significantly reduce NOx pollution, however, N2O emission rises.

Effects of EAF Operations on Water‐Cooling Panel Overheating

An electric arc furnace (EAF) is a furnace that utilizes mainly electric energy to melt scraps into liquid. Above the liquid steel is called the freeboard, and combustion that happens here can significantly heat the furnace wall, resulting in overheating issues on water‐cooling panels. In this study, a comprehensive computational fluid dynamics (CFD) model is developed to predict the side wall temperature distribution of an EAF. The comprehensive CFD model is integrated into a coherent jet, a DC electric arc, and a slag foaming models.

Dynamic modeling of a water tube boiler

AbstractThe present work aims to develop an integrated heat transfer and hydrodynamic model for the study of boiler dynamics in fluctuating load conditions. A transient heat transfer model has been developed to estimate water side heat transfer and it is directly integrated with the hydrodynamic model. Two independent natural circulation circuits for furnace water wall and convection tube bank have been considered due to differences in heat transfer, dryness fraction, and void fraction. The transient heat transfer model calculates the heat transfer and water wall temperature of the various sections to calculate total gas side heat transfer, gas temperature profile, and waterside heat transfer in the furnace water wall and convection tube bank. Mass momentum and energy conservation equations are generated for both natural circulation circuits using the estimated value of waterside heat transfer of the transient heat transfer model. These equations are integrated with mass and energy conservation equations for the drum below water level and drum above water level to generate a system of equations to estimate drum pressure and water level fluctuation. This model has been extended for boiler feedback control systems, including the load management and the water level control system.

Root cause study on an uncommon coating adhesion failure of hot-dip galvanized boron added low carbon steel

In this study, the root cause of an uncommon coating adhesion failure of hot-dip galvanized boron added low carbon steel was investigated. Metallurgical characterizations were performed by GDOES, SEM, AES, FIB and EDS. It was found that the coating adhesion failure was caused by the enrichment of boron at the coating/steel interface, which significantly prevented the formation of Fe-Al inhibition layer. The root cause of boron enrichment was further attributed to the external oxidation of boron during the annealing process. The vaporization of B2O3 and the formation of BN in the annealing furnace polluted the rollers and the inner furnace walls, which caused further boron contamination on the following steel surface. The suppression of boron external oxidation by dew point increasing effectively improved the coating adhesion of hot-dip galvanized boron added steel.

Application and comparative analysis of radiative heat transfer models for coal-fired furnace

Thermal radiation is a crucial mode of heat transfer in the industrial furnace. The present article compares various radiative heat transfer models for non-gray gases environments with typical application to the pulverized coal-fired furnace. An open source CFD software OpenFOAM is used to implement a three-dimensional photon Monte Carlo (PMC) method for radiation from gray gases and first-order spherical harmonics (P 1-method), discrete ordinates method (DOM) and zonal method for radiation from non-gray gases. The non-gray radiation properties are calculated using the weighted-sum-of-gray-gases (WSGG) and full-spectrum k-distribution models. The PMC method is employed as a benchmark for comparing the accuracy of the P 1-method and the DOM for gray gas environment, and the zonal method is employed as a benchmark for comparing the accuracy of P 1-method and DOM for the non-gray gas environment. The zonal method and PMC are validated against the exact solution for plane-parallel medium filled with a gray gas. The accuracy of the P 1-method and DOM is analyzed and compared with the zonal method for non-gray gas radiation inside a cubical box of 1 m sides. The effect of coal and ash particle’s radiative properties on the radiative heat transfer has been analyzed. The k-distribution model along with radiation due to coal and ash particles is presented. The variation in absorption and scattering efficiency due to particle size and the complex index of refraction is analyzed for different types of coal and ash particles. Isotropic, forward scattering, and δ-Eddington approximation are compared with the anisotropic scattering using Mie-theory. The coal and ash particle’s radiative properties are calculated using the Mie-theory and are averaged using Planck intensity distribution. The particle size of the coal and ash is a more critical parameter compared to the complex index of refraction. The slight variation in projected area per unit coal and ash particle leads to a significant change in the radiative heat source and radiative heat flux at the wall of industrial furnace.

Manufacturing and Improving Engineering Properties of Silica Bricks from Raw Materials

Refractories are mineral and chemical-, based, materials with excellent heat resistance, making them ideal for use in the construction of ovens, furnace walls industries. According to this our research is concerned to study the effect of addition of (4% CaO) and (5% graphite) on the silica brick properties. Different amounts of CaO and Graphite were included in the white sand (raw ingredients) of silica bricks as a binder to prepare the composition then the composition were sintered using Different sintering temperatures ranging from (1000–1400)𝛐C under static air. Density, thermal conductivity, porosity, and water absorption Compression there was power tested after sintering. XRD analysis was used to identify raw materials’ physical, chemical, and mechanical qualities, as well as their mineralogical composition. Addition of Graphite to the firebrick mixture increased the challenges of getting good densification out of firebrick specimens with enhancement of the compressive, strength, bulk density especially at low firing temperatures since it increases formation of glassy phase as compared with 4%CaO, Addition of 4% CaO to silica brick the density of firebrick decreased, and the porosity and water absorption increased. Thermal conductivity of firebrick is decreased for 5% Graphite in comparison with 4% CaO to produce refractory silica brick with high quality of heat resistance, making them ideal for use in the construction of ovens, furnace walls industries.

Pengaruh Variasi Daya Pompa pada System Pendinginan TEG terhadap Tegangan yang Dihasilkan TEG

The amount of heat energy wasted on the furnace wall is of concern to researchers who are trying to utilize the heat energy wasted from a furnace wall as a generator or source of electricity. The waste heat from the combustion in the furnace can now be used as a source of electricity. The waste heat is converted into electricity using a thermoelectric generator, the TEG generator is an electrical generator device that converts heat (temperature difference) directly into electrical energy. In this research, the heat used is the cylindrical wall of the furnace with variations in the size of the pump that flows the coolant to the waterblock, to determine the efficiency and magnitude of the power pump used to cool the hot side of the TEG, which produces a high temperature difference and also produces large electrical energy. thermoelectric generator module reused 4 pieces SP1848 27145 SA module.

Significant energy saving in industrial natural draught furnace: A model-based investigation

• Model based simulation is carried out for industrial scale natural drought cabin furnace. • Aspen Hysys and exchanger design rigorous (EDR) program used for modelling and simulation. • Sensitivity analysis was carried out to predict the impact of several parameters on the furnace efficiency. • The study shows potential of significant savings in energy, operational cost and carbon footprint. In all industrial petrochemical plants and refineries, the furnace is the source of heat resulting from fuel combustion with air. The model-based furnace simulation is considered one of the efficient methods help to reduce the energy loss and maintain fixed refinery revenues, conserving energy, and finally reducing external fuel consumption and total fuel cost. In this paper, a model-based simulation is carried out for a natural air draught industrial scale furnace related to Liquified Petroleum Gas (LPG) production plant in Libya to thoroughly investigate the most responsible factors in lowering the furnace butane exit temperature, which is supposed to be two degrees Fahrenheit higher than inlet temperature. Therefore, to resolve this industrial problem, Aspen Hysys V10, coupling with EDR (exchanger design and rating) is used to carry out rigorous model-based simulation. This is specifically used to assess the impact of heat loss from inside the firebox to the surrounding medium and heat loss from the furnace stack and walls, besides the effect of excess air on the furnace efficiency. Furthermore, this research intends to verify whether the operating conditions, such as furnace tubes inlet flow rate, temperature and pumping pressure, are conforming to the upstream process design specifications or need to be adjusted. The results confirm that increasing furnace outlet temperature two degrees Fahrenheit from off specification 190 °F instead of 184 °F is successfully achieved by decreasing upstream stream flowrate 25% below the operating value and cutback excess air gradually until 20%. Also, the results clarify the necessity of increasing the flue gas temperature by 7% over design condition, to gain a significant reduction of heat loss of 31.6% and reach as low as 35.5 MBtu/hr. This improvement is achieved using optimum operating conditions of an excess air of 20%, and flue gas oxygen content of 3.3% delivered to stack. Accordingly, the furnace efficiency has been increased by 18% to hit 58.9%. Furthermore, the heat loss from the furnace walls can be also reduced by 68% from 5.41 MBtu/hr to 1.7 MBtu/hr by increasing the refractory wall thickness to 6 in., which entails an increase in the furnace efficiency by 3.66% to reach 58.96%. Decreasing the heat loss fraction through the refractory wall, pip doors, expansion windows and refractory hair cracks would also increase the efficiency by 21% to reach a high of 59.7%. Accordingly, a significant reduction in daily fuel consumption is observed, which costs 1.7 M$ per year. The outcomes of this research clearly show the potential of reducing the operation and maintenance costs significantly.

Capacity-dependent configurations of S–CO2 coal-fired boiler by overall analysis with a unified model

Supercritical carbon dioxide (S–CO2) coal-fired power systems have been widely investigated due to its high efficiency and compactness. These power systems can range between 50 and 1000 MW and thus the corresponding boilers actually operate under dramatically different conditions. It is necessary to investigate the inherent relationship among different capacity S–CO2 boilers, which not only bring new theoretical understandings but also help improve practical designs. In this work, a unified model is proposed to investigate both thermal-hydraulic and thermodynamic performance. Furthermore, it is applied to evaluate the relationship between power capacity and boiler configuration. It is shown that small capacity furnaces suffer from overheating in the furnace wall and the optimized cooling wall is suggested to tackle this issue. Moreover, it is found that high pressure drop in the cooling wall of large capacity furnaces results in significant penalty on the cycle efficiency. For the popular 1000 MW boiler, an optimized configuration is suggested by moving the second reheating into the horizontal flue of boiler, achieving a lower pressure drop and an improved cycle efficiency from 35.4% to 50.09%. Finally, three recommendations for the capacity-dependent configurations are presented.

Analytical and numerical investigations on the high temperature upgrading solution of subcritical boilers

Currently there still exist a large base of subcritical coal-fired boilers remaining in operation worldwide. Improving their thermal efficiency is critical for these units to reduce the cost of electricity and meet the increasingly stringent efficiency regulations. This paper presented an economic high temperature upgrading retrofit solution for these subcritical units in which the final superheat and reheat steam temperatures are elevated from 540 °C to 600 °C level while the steam pressures remain at subcritical such that the retrofit can be made with minimum modifications to the boiler to reduce retrofit cost and technical risk. A systematic analysis was first conducted to deduce the best boiler heating surface modification option to achieve such significant increase of boiler steam temperatures. The analysis shows that replacing part of the furnace water wall below the furnace exit with wall superheater is the most viable and economic boiler modification design. A three-dimensional computational fluid dynamics (CFD) simulation was then conducted for a typical 320 MW subcritical boiler design to verify the feasibility of this design and determine the area of furnace wall that needs to be modified to achieve the target steam temperatures. The results show that with only 3.6 m height of furnace wall replaced with wall superheater both the superheat and reheat steam temperatures can reach the target 600 °C level even without any modification made to the reheaters. With this heating surface modification design, the efficiency of the existing subcritical power plants can be improved considerably with minimum boiler retrofit work. More importantly, this technology is going to help the plant owners meet the increasingly stringent efficiency and emission regulations mandated by the government and place them in a better position to continue operating these units.

Experimental study on combustion optimization of four-corner tangential boiler for alleviating high temperature corrosion

In order to reduce the volume fraction of H2S in the water wall area of the four-corner tangential boiler and achieve the purpose of alleviating the high temperature corrosion of the water wall, a thorough test was carried out on the 600MW boiler. The results show that the high temperature corrosion of the water wall under high load is obviously more serious than that under low load, the high temperature corrosion of the water wall of the front wall is more serious than that of the other walls, and the high temperature corrosion of the furnace wall area downstream of the burner is generally higher than that of the other walls. Other areas. The reason for this phenomenon is that the uniformity of the pulverized coal quantity in each pulverized tube is large, the air distribution is unreasonable, the primary and secondary air are separated, and the secondary air cannot completely cover the primary air; The uniformity of pulverized coal distribution, the proper increase of the total air volume, and the proper increase of the perimeter air volume can significantly reduce the volume fraction of H2S in the water wall area and alleviate high temperature corrosion.

Experimental performance analysis of 16 m2 solar Scheffler system for jaggery making

The process of making jaggery involves heating and evaporating sugarcane juice with the addition of thermal energy. Dry bagasse is used as a thermal energy source in the traditional jaggery manufacturing process. Traditional methods of making jaggery have limitations in terms of energy loss due to poor combustion, energy loss via exhaust gases, and other losses related to the furnace wall. Additionally, burning bagasse pollutes the environment. To overcome these problems, the steam energy generated by the solar Scheffler system is used to power the jaggery-making process in this paper. The performance of a 16 m2 Scheffler is evaluated to estimate the amount of jaggery produced and the production time. The experiment was carried out with a fixed amount of sugarcane juice, i.e., 2500 ml, under three different radiation conditions. Under maximum beam radiation conditions, i.e., 754 W/m2 during the experiment, the receiver power and thermal energy efficiency are 5.2 kW and 63.5 %, respectively. The energy required to produce 1 kg of jaggery under maximum radiation conditions (754 W/m2) is 285 W for 130 min. More precisely, 60 min for steam generation and 70 min. for jaggery production. Under maximum radiation conditions (754 W/m2) with 63.5% receiver efficiency, this Scheffler system is capable of producing approximately 16.14 kg of jaggery in 130 min. of duration. The maximum amount of jaggery produced is clearly dependent on the receiver power available for steam generation, as evidenced by the summary of results obtained during the first, second, and third experiments.By improving the thermal efficiency of the receiver and reducing the amount of boiling power required, we can reduce the time required for the production of jaggery, also increasing the quantity of jaggery produced.

Scientific Analysis for Furnace Walls of the Joseon Dynasty Excavated in Southern Region of the Korean Peninsula

A study on the Joseon Dynasty’s furnace walls, excavated from south Korea, was conducted to identify the correlations and differences of the furnace walls found in Jeolla and Gyeongsang regions. Three ruins in the Jeolla region and two in the Gyeongsang region were selected for the analysis. The results showed a layer change depending on the degree of plasticity and difference in the number of layers and particle phase. Furthermore, although the temperature to be subjected to heat was divided into 1300°C and 1100°C, it was not a phenomenon that appeared according to the region. Additionally, analysis result of major components revealed that the TiO&lt;sub&gt;2&lt;/sub&gt; content of most samples does not exceed 1wt%, This means that the furnace did not smelt iron sand or smelted it into low-titanium sand. This study indicated a slight similarity between the furnace walls found in the two regions, and the correlation was determined based on the nature of the ruins, raw materials of the metals ores, and composition of the raw materials constituting the furnace walls.

CFD Modeling of Multiphase Flow in an SKS Furnace with New Tuyere Arrangements

There has been a great deal of focus on the optimization of tuyere arrangements in SKS bottom blown copper smelting furnaces since the last decade, as the improved furnace operation efficiency of SKS technology has potential that cannot be ignored. New –x + 0 + x deg tuyere arrangements with 14 tuyeres are proposed in this research paper. Using a previously verified numerical model, CFD tests on the velocity distribution and wall shear stress for scaled-down SKS furnace models were conducted, with a constant total volumetric gas flow rate, and different operating parameters and furnace cross-section geometries. The results indicate that, at a relatively low gas injection speed compared with the previously optimized tuyere arrangement, although the –x +0 +x deg tuyere arrangements are unable to supply enhanced agitation in the typical round furnaces, they achieve better performance in elliptical furnaces. At a comparatively higher gas injection speed, the – x + 0 + x deg tuyere arrangements can improve the agitation performance in a round furnace while maintaining an acceptable wall shear stress on the bottom and side wall. The agitation enhancement with the − x +0 +x deg tuyere arrangements can essentially be attributed to stronger interactions between bubble plumes and furnace side walls. To further exploit the advantages of the new tuyere arrangements, an optimized tuyere angle was confirmed by a full-scale furnace model simulation.