Blast furnace(BF)burden surface contains the most abundant,intuitive and credible smelting information and acquiring high-definition and high-brightness optical images of which is essential to realize precise material...Blast furnace(BF)burden surface contains the most abundant,intuitive and credible smelting information and acquiring high-definition and high-brightness optical images of which is essential to realize precise material charging control,optimize gas flow distribution and improve ironmaking efficiency.It has been challengeable to obtain high-quality optical burden surface images under high-temperature,high-dust,and extremelydim(less than 0.001 Lux)environment.Based on a novel endoscopic sensing detection idea,a reverse telephoto structure starlight imaging system with large field of view and large aperture is designed.Combined with a water-air dual cooling intelligent self-maintenance protection device and the imaging system,a starlight high-temperature industrial endoscope is developed to obtain clear optical burden surface images stably under the harsh environment.Based on an endoscope imaging area model,a material flow trajectory model and a gas-dust coupling distribution model,an optimal installation position and posture configuration method for the endoscope is proposed,which maximizes the effective imaging area and ensures large-area,safe and stable imaging of the device in a confined space.Industrial experiments and applications indicate that the proposed method obtains clear and reliable large-area optical burden surface images and reveals new BF conditions,providing key data support for green iron smelting.展开更多
In order to improve the thermal properties of coke, an industrial experiment on the coke spraying with ZBS additive solution was carried out at coking plant and No. 6 blast furnace (2 000 m^3 ) of Kunming Iron and S...In order to improve the thermal properties of coke, an industrial experiment on the coke spraying with ZBS additive solution was carried out at coking plant and No. 6 blast furnace (2 000 m^3 ) of Kunming Iron and Steel Co Ltd. The coke reaction index (CRI) of the coke spraying with ZBS additive solution decreases by 10. 56 %, and the coke strength after reaction (CSR) increases by 7.80% in comparison with those of the un-sprayed coke. During the experiment, the average iron output increases by 66. 69 t/d, and the coke rate is reduced by 5. 21 kg per ton iron, while the fluctuation of furnace temperture is small, and sulphur content in hot metal and 100% of hot metal are acceptable.展开更多
Heat losses from the furnaces depend on the design and size. The surface heat loss from the bottom of an industrial AC electric arc furnace (EAF) possesses an important fraction of overall losses. So in this study the...Heat losses from the furnaces depend on the design and size. The surface heat loss from the bottom of an industrial AC electric arc furnace (EAF) possesses an important fraction of overall losses. So in this study the transient temperature variation at the bottom of the EAF was investigated. The transient temperature analysis was carried out using MATLAB computer program. T=T(r, t) for different bottom lining layers was depicted.展开更多
The heat transfer analysis was performed for an AC electric arc furnace (EAF). Heat losses by conduction, convection and radiation from outer surface, roof, bottom and electrodes of EAF were determined in detail. Some...The heat transfer analysis was performed for an AC electric arc furnace (EAF). Heat losses by conduction, convection and radiation from outer surface, roof, bottom and electrodes of EAF were determined in detail. Some suggestions about decreasing heat losses were presented.展开更多
In this paper we describe a hybrid system approach for high consumption industrial furnace control. The problem is observed in systematic way starting from the need for modeling this system as hybrid. For description ...In this paper we describe a hybrid system approach for high consumption industrial furnace control. The problem is observed in systematic way starting from the need for modeling this system as hybrid. For description of this behavior we use the Hybrid System Description Language. After that, we design an optimal controller for the furnace and we simulate and compare the controller with other relevant predictive controllers. We have shown that using the hybrid approach for control of industrial furnaces leads to significant improvement of the control system performances.展开更多
This is a historical compilation and analysis of the world-wide development of kilns and furnaces, covering those ones ranging from ancient earthenware kilns to modern high-tech furnaces、 including nuclear reactors a...This is a historical compilation and analysis of the world-wide development of kilns and furnaces, covering those ones ranging from ancient earthenware kilns to modern high-tech furnaces、 including nuclear reactors and fuel cells. Special emphasis is on energy conservation and environmental protection. the historical lessons from which can be applied to future activities.展开更多
In developing countries,solar energy is the largest source of energy,accounting for 35%–45%of the total energy supply.This energy resource plays a vital role in meeting the energy needs of the world,especially in Vie...In developing countries,solar energy is the largest source of energy,accounting for 35%–45%of the total energy supply.This energy resource plays a vital role in meeting the energy needs of the world,especially in Vietnam.Vietnam has favorable natural conditions for this energy production.Because it is hot and humid,and it has much rainfall and fertile soil,biomass develops very quickly.Therefore,byproducts from agriculture and forestry are abundant and continuously increasing.However,byproducts that are considered natural waste have become the cause of environmental pollution;these include burning forests,straw,and sawdust in the North;and rice husks dumped into rivers and canals in the Mekong Delta region.Biomass energy is provided in a short cycle,is environmentally safe to use and is encouraged by organizations that support sustainable development.Taking advantage of this energy source provides energy for economic development and ensures environmental protection.Due to the abovementioned favorable conditions,many biomass energy plants are being built in Vietnam.Like other renewable energy investment projects,the selection of the construction contractor,the selection of equipment for the installation of the power plant,and the choice of construction site are complex multi-criteria decisions.In this case,decisionmakers must evaluate many qualitative and quantitative factors.These factors interact with each other and it is difficult to use personal experience to choose the optimal solution for such complex decision-making problems,especially in a fuzzy decision-making environment.Therefore,in this study,the authors use a Multi-Criteria Decision-Making(MCDM)model that uses a Fuzzy Analytic Hierarchy Process(FAHP)model and the Combined Compromise Solution(CoCoSo)algorithm to select biomass furnace suppliers utilizing both qualitative and quantitative factors.Furthermore,the results of this work will provide the first look at a hybrid CoCoSo/FAHP method that decision-makers in other fields can use to find the best supplier.展开更多
High-temperature performance tests of chromium-containing stuffing sand for a steel ladle w ith different ratios w ere performed. A high-temperature simulation test furnace w as used to analyze the influence of the co...High-temperature performance tests of chromium-containing stuffing sand for a steel ladle w ith different ratios w ere performed. A high-temperature simulation test furnace w as used to analyze the influence of the composition ratio of ladle filler sand and sintering time on the high-temperature compression resistance of chromium-containing stuffing sand in the temperature range of 1 500- 1 600 ℃. The results show that the refractoriness of ladle filler sand w as the low est( only 1 610 ℃) w hen the composition ratio of chromite sand and silica sand w as 6∶ 4. M oreover,the high-temperature compression resistance w as high w hen the content of chromite sand w as at 70%; the resistance increased w ith increasing sintering time. When the sintering time w as extended at a temperature of 1 600 ℃,the high-temperature compression resistance of ladle filler sand first increased and then decreased after being overburnt.展开更多
Aluminous refractory materials with high alumina contents are widely used in the steel industry,and the higher the alumina content,the higher the working temperature.Properties such as high refractoriness and thermal ...Aluminous refractory materials with high alumina contents are widely used in the steel industry,and the higher the alumina content,the higher the working temperature.Properties such as high refractoriness and thermal shock resistance lead these refractory materials to be used as channel linings of blast furnaces,where they are exposed to the attack by slag,molten steel,working cycles and sudden temperature changes between 25℃(room temperature)and 1520℃(the temperature of molten pig iron).In this work,microstructural changes in post-mortem aluminous refractory bricks were investigated by apparent porosity,X-ray diffraction analysis(XRD),Fourier transform infrared spectroscopy(FTIR),scanning electron microscopy,and X-ray dispersion energy spectrometry(SEM/EDS).The results showed an increase in the apparent porosity and the bulk density and the presence of the phases mullite,sillimanite,alumina,and quartz in the post-mortem brick.Calcium and magnesium were not detected in the microstructure of the post-mortem brick,indicating that slags did not corrode these refractory materials.Therefore,the microstructural changes that occurred in the post-mortem bricks must be due to thermal cycling.In the X-ray diffraction(XRD)test,mullite,sillimanite,quartz,andα-alumina phases were identified.These results indicate that the aluminous refractory was obtained from sillimanite.In infrared spectroscopy(FTIR)it was possible to identify the vibration bands referring to the Si-O and Al-O bonds.The increase in the porosity is a result of cracks caused by work cycles at high temperatures and the temperature gradient to which the refractory was subjected during use.Through the micrograph it was possible to identify the presence of acicular mullite.The absence of magnesium and calcium in the microanalysis results by energy dispersed X-ray spectrometry(EDS)indicates that there was no infiltration by slag or liquid iron.These results indicate that the microstructural changes that occurred in the post-mortem aluminous refractory were of a thermal nature.展开更多
To diagnose the lining condition of the blast furnace hearth during its campaign, are widely used methods based on the analysis of the temperature characteristics of the refractory lining. Measurement of the temperatu...To diagnose the lining condition of the blast furnace hearth during its campaign, are widely used methods based on the analysis of the temperature characteristics of the refractory lining. Measurement of the temperature characteristics is performed by means of a few hundred thermocouples placed inside the refractory lining. The peculiarity of proposed and used mathematical models is a fully three-dimensional assessment of the refractory lining, presence mechanisms of adaptation to the actual thermal conductivity of refractories and optimization calculations to the work in the on-line mode. The new monitoring systems of the lining wear of the blast furnace hearth are established on 5 blast furnaces of integrated iron-and-steel works of China: No.4 by volume 3,200 m3 of “Jinan Iron & Steel Company” in Jinan (683 thermocouples), No.2 by volume 1,080 m3 of “Henan Jiyuan Iron & Steel (Group) Company” in Jiyuan (212 thermocouples), No.4 by volume 2,500 m3 of “Guangxi Liuzhou Iron & Steel (Group) Company” in Liuzhou (383 thermocouples), No.3 by volume 1,750 m3 of “Jinan Iron & Steel Company” in Jinan (524 thermocouples); No.1 by volume 1,750 m3 of “Jinan Iron & Steel Company” in Jinan (524 thermocouples).展开更多
JC 497-92 (96)1 Contents and Applied ScopeThis standard specifies the classification, shapes and dimensions, technical requirements, test methods, inspection rules, marking, packing, transportation, storage and qualit...JC 497-92 (96)1 Contents and Applied ScopeThis standard specifies the classification, shapes and dimensions, technical requirements, test methods, inspection rules, marking, packing, transportation, storage and quality certificate of direct-bonded magnesite-chrome bricks for building materials industry. This standard is applicable to the direct-bonded magnesite-chrome bricks for cement kiln, glass melting tank and other industrial furnaces.2 Normative ReferencesGB 2997: Test method for the apparent porosity, water absorption, bulk density and true porosity of dense shaped refractory productsGB 5070: Chemical analysis method for magnesite-Chrome refractoriesGB 5072: Test method for cold crushing strength of dense shaped refractory productsGB 5989: Test method for refractoriness under load of dense shaped refractory products (Differential, with rising temperature)GB 7320: Test method for thermal expansion of refractory productsGB 7321: Sample preparation for testing of dense shaped refractory productsGB 10324: Type definition of refractory productsGB 10325: Piling, sampling, acceptance, storage and transportation of refractory products展开更多
A high-temperature reduction roasting method was used to achieve metallic iron and zinc recovery from blast furnace gas ash(BFA).The reduction processes for Zn-containing and Fe-containing oxides were analyzed in deta...A high-temperature reduction roasting method was used to achieve metallic iron and zinc recovery from blast furnace gas ash(BFA).The reduction processes for Zn-containing and Fe-containing oxides were analyzed in detail by using ther-modynamic equilibrium calculation and the principle of minimum free energy.The results showed that the main reaction in the system is the reduction of ZnFe_(2)_(4)and iron oxides.Over the full temperature range,iron oxides were more easily reduced than zinc oxides.Regardless of the amount of CO contained in the system,the reduction of ZnO to Zn was difficult to proceed below the boiling point(906℃)of Zn.When the reduction temperature is below 906℃,the reduction process of zinc ferrate was ZnFe_(2)_(4)→ZnO;when the reduction temperature is above 906℃,its reduction process becomed ZnFe_(2)_(4)→ZnO→Zn(g).The metallization and dezincification rates of the BFA gradually increased with increasing reaction temperature.As the C/O ratio increased,the metallization and dezincification rates first increased and then decreased.The effect of reduction time on BFA reduction was similar to that of reaction temperature.展开更多
Copper staves have been equipped on nearly all of BF (blast furnaces) with volume over than 1000 m3 in China since their introduction from abroad about more than 10 years ago. Because of short application and lack o...Copper staves have been equipped on nearly all of BF (blast furnaces) with volume over than 1000 m3 in China since their introduction from abroad about more than 10 years ago. Because of short application and lack of experience, phenomena of thickened or naked of copper stave happen occasionally which influence production severely. So it is important to study the model of forming-accretion on BF copper stave and realize real-time monitoring of forming-accretion on different copper staves. Therefore, mathematic model of calculating accretion thickness by heat flow of BF is proposed, and the calculated results indicate that accretion thickness could be kept at a reasonable range of around 50 mm by controlling heat flux around 22.0 kW/mz. The monitoring program based on the model was applied to a certain BF in China successfully, and it is found that slip of BF near the inner wall is one of most important reasons that cause fluctuation of accretion thickness. During the period of scheduled maintenance of the certain BF, the thickness of accretion measured through the static pressure holes is in good accordance with the value calculated by the monitoring program, so the results calculated by the monitoring program can be used to guide industrial production展开更多
The flow characteristics of high-temperature flue gas are important in the heat transfer of coal-water slurry(CWS) combustion furnaces.The flow field of a 250 kg/h vertical-type slag tap cyclone furnace was non-intr...The flow characteristics of high-temperature flue gas are important in the heat transfer of coal-water slurry(CWS) combustion furnaces.The flow field of a 250 kg/h vertical-type slag tap cyclone furnace was non-intrusively investigated,using two-dimensional particle-image velocimetry(2D PIV).The method was verified using traceable fly ash particles in high-temperature flue gas.The flow field of the flue gas was analyzed with a time-averaged method,based on which the effects of excess air ratio and loading were investigated.The flue gas separated by a gas separator maintained good rigidity near the furnace wall,rather than eroding the heating surface.Numerical simulations validated the reliability of PIV under the actual circumstances within the furnace.This study provides guidelines for applying 2D PIV in analyzing flue gas in thermal test boilers.展开更多
基金the National Natural Science Foundation of China(62273359)the General Project of Hunan Natural Science Foundation of China(2022JJ30748)the National Major Scientific Research Equipment of China(61927803)。
文摘Blast furnace(BF)burden surface contains the most abundant,intuitive and credible smelting information and acquiring high-definition and high-brightness optical images of which is essential to realize precise material charging control,optimize gas flow distribution and improve ironmaking efficiency.It has been challengeable to obtain high-quality optical burden surface images under high-temperature,high-dust,and extremelydim(less than 0.001 Lux)environment.Based on a novel endoscopic sensing detection idea,a reverse telephoto structure starlight imaging system with large field of view and large aperture is designed.Combined with a water-air dual cooling intelligent self-maintenance protection device and the imaging system,a starlight high-temperature industrial endoscope is developed to obtain clear optical burden surface images stably under the harsh environment.Based on an endoscope imaging area model,a material flow trajectory model and a gas-dust coupling distribution model,an optimal installation position and posture configuration method for the endoscope is proposed,which maximizes the effective imaging area and ensures large-area,safe and stable imaging of the device in a confined space.Industrial experiments and applications indicate that the proposed method obtains clear and reliable large-area optical burden surface images and reveals new BF conditions,providing key data support for green iron smelting.
文摘In order to improve the thermal properties of coke, an industrial experiment on the coke spraying with ZBS additive solution was carried out at coking plant and No. 6 blast furnace (2 000 m^3 ) of Kunming Iron and Steel Co Ltd. The coke reaction index (CRI) of the coke spraying with ZBS additive solution decreases by 10. 56 %, and the coke strength after reaction (CSR) increases by 7.80% in comparison with those of the un-sprayed coke. During the experiment, the average iron output increases by 66. 69 t/d, and the coke rate is reduced by 5. 21 kg per ton iron, while the fluctuation of furnace temperture is small, and sulphur content in hot metal and 100% of hot metal are acceptable.
文摘Heat losses from the furnaces depend on the design and size. The surface heat loss from the bottom of an industrial AC electric arc furnace (EAF) possesses an important fraction of overall losses. So in this study the transient temperature variation at the bottom of the EAF was investigated. The transient temperature analysis was carried out using MATLAB computer program. T=T(r, t) for different bottom lining layers was depicted.
文摘The heat transfer analysis was performed for an AC electric arc furnace (EAF). Heat losses by conduction, convection and radiation from outer surface, roof, bottom and electrodes of EAF were determined in detail. Some suggestions about decreasing heat losses were presented.
文摘In this paper we describe a hybrid system approach for high consumption industrial furnace control. The problem is observed in systematic way starting from the need for modeling this system as hybrid. For description of this behavior we use the Hybrid System Description Language. After that, we design an optimal controller for the furnace and we simulate and compare the controller with other relevant predictive controllers. We have shown that using the hybrid approach for control of industrial furnaces leads to significant improvement of the control system performances.
文摘This is a historical compilation and analysis of the world-wide development of kilns and furnaces, covering those ones ranging from ancient earthenware kilns to modern high-tech furnaces、 including nuclear reactors and fuel cells. Special emphasis is on energy conservation and environmental protection. the historical lessons from which can be applied to future activities.
基金financially supported by the National Natural Science Foundation of China(No.51474161)the Hunan Provincial Co-innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources
文摘In developing countries,solar energy is the largest source of energy,accounting for 35%–45%of the total energy supply.This energy resource plays a vital role in meeting the energy needs of the world,especially in Vietnam.Vietnam has favorable natural conditions for this energy production.Because it is hot and humid,and it has much rainfall and fertile soil,biomass develops very quickly.Therefore,byproducts from agriculture and forestry are abundant and continuously increasing.However,byproducts that are considered natural waste have become the cause of environmental pollution;these include burning forests,straw,and sawdust in the North;and rice husks dumped into rivers and canals in the Mekong Delta region.Biomass energy is provided in a short cycle,is environmentally safe to use and is encouraged by organizations that support sustainable development.Taking advantage of this energy source provides energy for economic development and ensures environmental protection.Due to the abovementioned favorable conditions,many biomass energy plants are being built in Vietnam.Like other renewable energy investment projects,the selection of the construction contractor,the selection of equipment for the installation of the power plant,and the choice of construction site are complex multi-criteria decisions.In this case,decisionmakers must evaluate many qualitative and quantitative factors.These factors interact with each other and it is difficult to use personal experience to choose the optimal solution for such complex decision-making problems,especially in a fuzzy decision-making environment.Therefore,in this study,the authors use a Multi-Criteria Decision-Making(MCDM)model that uses a Fuzzy Analytic Hierarchy Process(FAHP)model and the Combined Compromise Solution(CoCoSo)algorithm to select biomass furnace suppliers utilizing both qualitative and quantitative factors.Furthermore,the results of this work will provide the first look at a hybrid CoCoSo/FAHP method that decision-makers in other fields can use to find the best supplier.
文摘High-temperature performance tests of chromium-containing stuffing sand for a steel ladle w ith different ratios w ere performed. A high-temperature simulation test furnace w as used to analyze the influence of the composition ratio of ladle filler sand and sintering time on the high-temperature compression resistance of chromium-containing stuffing sand in the temperature range of 1 500- 1 600 ℃. The results show that the refractoriness of ladle filler sand w as the low est( only 1 610 ℃) w hen the composition ratio of chromite sand and silica sand w as 6∶ 4. M oreover,the high-temperature compression resistance w as high w hen the content of chromite sand w as at 70%; the resistance increased w ith increasing sintering time. When the sintering time w as extended at a temperature of 1 600 ℃,the high-temperature compression resistance of ladle filler sand first increased and then decreased after being overburnt.
基金acknowledged DEQ/IT/UFRRJ,FEG/UNESP-Guaratinguetáand EEL/USP-Lorena for their support in carrying out the analyses.
文摘Aluminous refractory materials with high alumina contents are widely used in the steel industry,and the higher the alumina content,the higher the working temperature.Properties such as high refractoriness and thermal shock resistance lead these refractory materials to be used as channel linings of blast furnaces,where they are exposed to the attack by slag,molten steel,working cycles and sudden temperature changes between 25℃(room temperature)and 1520℃(the temperature of molten pig iron).In this work,microstructural changes in post-mortem aluminous refractory bricks were investigated by apparent porosity,X-ray diffraction analysis(XRD),Fourier transform infrared spectroscopy(FTIR),scanning electron microscopy,and X-ray dispersion energy spectrometry(SEM/EDS).The results showed an increase in the apparent porosity and the bulk density and the presence of the phases mullite,sillimanite,alumina,and quartz in the post-mortem brick.Calcium and magnesium were not detected in the microstructure of the post-mortem brick,indicating that slags did not corrode these refractory materials.Therefore,the microstructural changes that occurred in the post-mortem bricks must be due to thermal cycling.In the X-ray diffraction(XRD)test,mullite,sillimanite,quartz,andα-alumina phases were identified.These results indicate that the aluminous refractory was obtained from sillimanite.In infrared spectroscopy(FTIR)it was possible to identify the vibration bands referring to the Si-O and Al-O bonds.The increase in the porosity is a result of cracks caused by work cycles at high temperatures and the temperature gradient to which the refractory was subjected during use.Through the micrograph it was possible to identify the presence of acicular mullite.The absence of magnesium and calcium in the microanalysis results by energy dispersed X-ray spectrometry(EDS)indicates that there was no infiltration by slag or liquid iron.These results indicate that the microstructural changes that occurred in the post-mortem aluminous refractory were of a thermal nature.
文摘To diagnose the lining condition of the blast furnace hearth during its campaign, are widely used methods based on the analysis of the temperature characteristics of the refractory lining. Measurement of the temperature characteristics is performed by means of a few hundred thermocouples placed inside the refractory lining. The peculiarity of proposed and used mathematical models is a fully three-dimensional assessment of the refractory lining, presence mechanisms of adaptation to the actual thermal conductivity of refractories and optimization calculations to the work in the on-line mode. The new monitoring systems of the lining wear of the blast furnace hearth are established on 5 blast furnaces of integrated iron-and-steel works of China: No.4 by volume 3,200 m3 of “Jinan Iron & Steel Company” in Jinan (683 thermocouples), No.2 by volume 1,080 m3 of “Henan Jiyuan Iron & Steel (Group) Company” in Jiyuan (212 thermocouples), No.4 by volume 2,500 m3 of “Guangxi Liuzhou Iron & Steel (Group) Company” in Liuzhou (383 thermocouples), No.3 by volume 1,750 m3 of “Jinan Iron & Steel Company” in Jinan (524 thermocouples); No.1 by volume 1,750 m3 of “Jinan Iron & Steel Company” in Jinan (524 thermocouples).
文摘JC 497-92 (96)1 Contents and Applied ScopeThis standard specifies the classification, shapes and dimensions, technical requirements, test methods, inspection rules, marking, packing, transportation, storage and quality certificate of direct-bonded magnesite-chrome bricks for building materials industry. This standard is applicable to the direct-bonded magnesite-chrome bricks for cement kiln, glass melting tank and other industrial furnaces.2 Normative ReferencesGB 2997: Test method for the apparent porosity, water absorption, bulk density and true porosity of dense shaped refractory productsGB 5070: Chemical analysis method for magnesite-Chrome refractoriesGB 5072: Test method for cold crushing strength of dense shaped refractory productsGB 5989: Test method for refractoriness under load of dense shaped refractory products (Differential, with rising temperature)GB 7320: Test method for thermal expansion of refractory productsGB 7321: Sample preparation for testing of dense shaped refractory productsGB 10324: Type definition of refractory productsGB 10325: Piling, sampling, acceptance, storage and transportation of refractory products
基金This work was supported by the National Natural Science Foundation of China(Grant No.51704021)Key Research and Development Projects of Sichuan Province(021YFG0114)+1 种基金Key Research and Development Projects of Shandong Province(2021CXGC010209)the Joint Funds of the National Natural Science Foundation of China(U1560203).
文摘A high-temperature reduction roasting method was used to achieve metallic iron and zinc recovery from blast furnace gas ash(BFA).The reduction processes for Zn-containing and Fe-containing oxides were analyzed in detail by using ther-modynamic equilibrium calculation and the principle of minimum free energy.The results showed that the main reaction in the system is the reduction of ZnFe_(2)_(4)and iron oxides.Over the full temperature range,iron oxides were more easily reduced than zinc oxides.Regardless of the amount of CO contained in the system,the reduction of ZnO to Zn was difficult to proceed below the boiling point(906℃)of Zn.When the reduction temperature is below 906℃,the reduction process of zinc ferrate was ZnFe_(2)_(4)→ZnO;when the reduction temperature is above 906℃,its reduction process becomed ZnFe_(2)_(4)→ZnO→Zn(g).The metallization and dezincification rates of the BFA gradually increased with increasing reaction temperature.As the C/O ratio increased,the metallization and dezincification rates first increased and then decreased.The effect of reduction time on BFA reduction was similar to that of reaction temperature.
文摘Copper staves have been equipped on nearly all of BF (blast furnaces) with volume over than 1000 m3 in China since their introduction from abroad about more than 10 years ago. Because of short application and lack of experience, phenomena of thickened or naked of copper stave happen occasionally which influence production severely. So it is important to study the model of forming-accretion on BF copper stave and realize real-time monitoring of forming-accretion on different copper staves. Therefore, mathematic model of calculating accretion thickness by heat flow of BF is proposed, and the calculated results indicate that accretion thickness could be kept at a reasonable range of around 50 mm by controlling heat flux around 22.0 kW/mz. The monitoring program based on the model was applied to a certain BF in China successfully, and it is found that slip of BF near the inner wall is one of most important reasons that cause fluctuation of accretion thickness. During the period of scheduled maintenance of the certain BF, the thickness of accretion measured through the static pressure holes is in good accordance with the value calculated by the monitoring program, so the results calculated by the monitoring program can be used to guide industrial production
基金supported by the National Basic Research Program of China(No.2012CB214906)the Natural Science Foundation of China(No.51176162)
文摘The flow characteristics of high-temperature flue gas are important in the heat transfer of coal-water slurry(CWS) combustion furnaces.The flow field of a 250 kg/h vertical-type slag tap cyclone furnace was non-intrusively investigated,using two-dimensional particle-image velocimetry(2D PIV).The method was verified using traceable fly ash particles in high-temperature flue gas.The flow field of the flue gas was analyzed with a time-averaged method,based on which the effects of excess air ratio and loading were investigated.The flue gas separated by a gas separator maintained good rigidity near the furnace wall,rather than eroding the heating surface.Numerical simulations validated the reliability of PIV under the actual circumstances within the furnace.This study provides guidelines for applying 2D PIV in analyzing flue gas in thermal test boilers.