Multiple-response optimization for melting process of aluminum melting furnace based on response surface methodology with desirability function

To reduce the fuel consumption and emissions and also enhance the molten aluminum quality,a mathematical model with user-developed melting model and burning capacity model,were established according to the features of melting process of regenerative aluminum melting furnaces.Based on validating results by heat balance test for an aluminum melting furnace,CFD(computational fluid dynamics) technique,in association with statistical experimental design were used to optimize the melting process of the aluminum melting furnace.Four important factors influencing the melting time,such as horizontal angle between burners,height-to-radius ratio,natural gas mass flow and air preheated temperature,were identified by PLACKETT-BURMAN design.A steepest descent method was undertaken to determine the optimal regions of these factors.Response surface methodology with BOX-BEHNKEN design was adopted to further investigate the mutual interactions between these variables on RSD(relative standard deviation) of aluminum temperature,RSD of furnace temperature and melting time.Multiple-response optimization by desirability function approach was used to determine the optimum melting process parameters.The results indicate that the interaction between the height-to-radius ratio and horizontal angle between burners affects the response variables significantly.The predicted results show that the minimum RSD of aluminum temperature(12.13%),RSD of furnace temperature(18.50%) and melting time(3.9 h) could be obtained under the optimum conditions of horizontal angle between burners as 64°,height-to-radius ratio as 0.3,natural gas mass flow as 599 m3/h,and air preheated temperature as 639 °C.These predicted values were further verified by validation experiments.The excellent correlation between the predicted and experimental values confirms the validity and practicability of this statistical optimum strategy.

CONTROLLING AND MONITORING THERMOTE NICAL PARAMETERS OF GLASS MELTING FURNACE

According to the characteristics of the ther-motechnical parameters such as temperature pressure and glass level for glass melting furnace, the design method for monitoring and controlling these parameters is introduced in this paper based on MACROMAX-2 concentrated and dis-tributedcontrol system. The configuration of management information and control loop is described, and research tests were performed to check the functions of system.

TWO-DIMENSIONAL MATHEMATICAL MODEL OF COMBUSTION SPACE IN GLASS MELTING FURNACES

Under some assumptions and dividing the combustion space into several isothermal zones and isothermal surface elements, a two-dimensional mathematical model for combustion space in cross-fired glass melting furnaces was constructed. The finite element method and the Gauss integration were used to calculate direct ex-change areas, and a inverse matrix was used to obtained the total ex-change areas. The temperature distributions were obtained by itera-tions. Some results were presented to show the effects of the fire tem-perature distribution, the convective -heat transfer coefficients and the heat losses through crown surfaces on the temperature distributions.

Innovation of Regenerator Checkerwork for Glass Melting Furnaces

Regenerator checkerwork for glass melting furnaces should have high resistance against thermal stress and chemical attack,high mechanical stability,high efficiency to recover the heat from waste gas and low tendency for clogging.This article reviews the innovation of the regenerator checkerwork from the past decades.The state of the art for optimised material choice and optimised checker shapes will be reported.

Melting Time Prediction Model for Induction Furnace Melting Using Specific Thermal Consumption from Material Charge Approach

A system-level evaluation was used to analyze the induction furnace operation and process system in this study. This paper presents an investigation into the relationship between the instantaneous chemical composition of a molten bath and its energy consumption in steelmaking. This was evaluated using numerical modelling to solve for the estimated melting time prediction for the induction furnace operation. This work provides an insight into the lowering of energy consumption and estimated production time in steelmaking using material charge balancing approach. Enthalpy computation was implemented to develop an energy consumption model for the molten metal using a specific charge composition approach. Computational simulation program engine (CastMELT) was also developed in Java programming language with a MySQL database server for seamless specific charge composition analysis and testing. The model performance was established using real-time production data from a cast iron-based foundry with a 1 and 2-ton induction furnace capacity and a medium carbon-based foundry with a 10- and 15-ton induction furnace capacity. Using parameter fitting techniques on the measured operational data of the induction furnaces at different periods of melting, the results from the model predictions and real-time melting showed good correlation between 81% - 95%. A further analysis that compared the relationship between the mass composition of a current molten bath and melting, time showed that energy consumption can be reduced with effective material balancing and controlled charge. Melting time was obtained as a function of the elemental charge composition of the molten bath in relation to the overall scrap material charge. This validates the approach taken by this research using material charge and thermodynamic of melting to optimize and better control melting operation in foundry and reduce traditional waste during iron and steel making.

Fireclay Refractory Bricks for Glass Melting Furnace

This standard is applicable to fireclay refractory bricks with unit weight ≥ 50 kg for glass melting furnaces.

Sintered AZS Bricks for Glass Melting Furnace

1 Scope This standard specifies the brand, technical requirements, test methods, inspection rules, marking, packing, transportation, storage, and quality certificate of sintered AZS bricks for glass melting furnace. This standard is applicable to sintered AZS bricks for glass melting furnace.

Fused Cast Alumina Refractory Products for Glass Melting Furnace

JC/T 494-92(96) 1 ScopeThis standard specifies the technical requirements, test methods, inspection rules, marking, packing, transportation, and storage of fused cast alumina refractory products for glass melting furnace. This standard is applicable to the fused cast alumina refractory products for glass melting furnace (called products for short).2 Normative ReferencesGB 2997 Test method for apparent porosity, water absorption, bulk density and true porosity of dense shaped refractory productsGB 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 10204 Test method for corrosion resistance of refractories for glass melting furnace to molten glassGB 10325 Stacking, sampling, acceptance, storage and transportation of shaped refractory productsGB 10326 Inspections of dimension, appearance and section of refractory productsGB/T 14351 Chemical analysis method of fused cast alumina refractoriesYB 4015 Sample preparation for testing of refractory products for glass melting furnaceYB 4016 Sampling and inspection of refractory products for glass melting furnaceJC 493 Fused cast zirconia corundum refractory products for glass melting furnace

Silica Refractory Bricks for Glass Melting Furnace

1 Scope This standard specifies the classification, technical requirements, test method, inspection rules, marking, packing, transportation, storage and quality certification of silica refractory bricks for glass melting furRaces.

Low Porosity Fireclay Bricks for Glass Melting Furnace

This standard specifies the classification, technical requirements, test methods, inspection rules, marking, packing, transportation, storage and quality certificate of low porosity fireclay bricks for glass melting furnace.

High Quality Silica Bricks for Glass Melting Furnace

This standard specifies the classification, technical requirements, test method, inspection rules, marking, packing, transportation, storage and quality certification of high quality silica bricks for glass melting furnace.

Molybdenum Electrodes Applied in Electric Melting Furnace

The conditions and points for attentions of molybdenum electrode, which used in glass melting furnace, are introduced. Problems in corrosion of molybdenum electrodes are analyzed through the glass components, temperature and current density, and how to eliminate bubble formation on the process. At last, the specific requests of the applications of molybdenum electrode in glass industry are presented.

Effect of MgO content in sinter on the softening–melting behavior of mixed burden made from chromium-bearing vanadium–titanium magnetite

The effect of sinter with different MgO contents on the softening-melting behavior of mixed burden made from chro- mium-bearing vanadium-titanium magnetite was investigated. The results show that with increasing MgO content in the sinter, the softening interval and melting interval increased and the location of the cohesive zone shifted downward slightly and became moderately thicker. The softening-melting characteristic value was less pronounced when the MgO content in the sinter was 2.98wt%-3.40wt%. Increasing MgO content in the sinter reduced the content and recovery of V and Cr in the dripped iron. In addition, greater MgO contents in the sinter resulted in the generation of greater amounts of high-melting-point components, which adversely affected the permeability of the mixed burden. When the softening-melting behavior of the mixed burden and the recovery of valuable elements were taken into account, proper MgO con- tents in the sinter and slag ranged from 2.98wt% to 3.40wt% and from 11.46wt% to 12.72wt%, respectively, for the smelting of burden made from chromium-bearing vanadium-titanium magnetite in a blast furnace.

Effect and function mechanism of sinter basicity on softening-melting behaviors of mixed burden made from chromium-bearing vanadium-titanium magnetite

The effect of sinter basicity on softening-melting behaviors of mixed burden made from chromium-bearing vanadium-titanium magnetite(Cr-V-Ti magnetite) was investigated and the function mechanism was simultaneously analyzed.The results show that with increasing sinter basicity from 1.71 to 2.36,the softening interval tends to increase from 149.3 ℃ to 181.7 ℃while the melting interval tends to decrease from 178.0 ℃ to 136.7 ℃.The location of cohesive zone moves downwards firstly and then ascends slightly,but the cohesive zone becomes thinner.The softening-melting characteristic value becomes small,which indicates that the permeability of burden column is improved.The dripping ratio of mixed burden tends to increase firstly and then decrease,which comes to the highest value of 74.50%when the sinter basicity is 2.13.The content and the recovery of V and Cr in dripping iron are all increased.The generation amount of components with high melting point in slag becomes little with the increase of sinter basicity,which could improve the permeability of mixed burden.Taking softening-melting behaviors of mixed burden and recovery of valuable elements into account,the proper sinter basicity is no less than 2.13 for smelting mixed burden made from Cr-V-Ti magnetite in blast furnace.

Evolution behavior and mechanism of iron carbon agglomerates under simulated blast furnace smelting conditions

Iron carbon agglomerates(ICA)are the composite burden for low-carbon blast furnace(BF)ironmaking.In order to optimize the reactivity of ICA according to the evolution characteristics of ICA in the BF smelting process,the evolution behavior and mechanism of different reactive ICA under simulated BF smelting conditions were studied.The results show that the existence of more sillimanite and aluminosilicate and less active sites of metallic iron will weaken gasification reaction and carburization ability of ICA-1(containing 10%iron ore).It weakens the promoting effect of ICA-1 on the reduction,softening,and melting of ferrous burdens and the dripping of slag-iron.The aluminosilicate with a high melting point decreases,the low melting point slag phase and Fe–Si alloy increase,and many active sites of metallic iron exist,which strengthen the gasification reaction and carburization ability of ICA-2(containing 30%iron ore).The promoting effect of ICA-2 on the reduction,softening,and melting of ferrous burdens and the dripping of slag-iron is significantly improved.The gasification reaction capacity of ICA-3(containing 35%iron ore)is reduced,and the improvement in ICA-3 on the softening–melting performance of mixed burdens is reduced.The appropriate proportion of iron ore in ICA is about 30%.

Glass Furnace Boost Technology-Series/Parallel Switch

In the paper, the characters and fields were introduced for utilizing the Series/Parallel Switch (SPS). The circuit principle of the SPS technology was analyzed in detailed, explained and illuminated. We understood clearly the difference between SPS and single-phase transformator by the figure and table. Finally, it summarized that the main characters of SPS.

Recent Development in Improving Energy Efficiency of Glass Furnaces

The energy required for continuous glass melting usually accounts for about 30~75% of the total energy consumptions supplied to the glass industry, and the energy cost contributes to about 10~25% of total glass manufacturing cost depending upon the type of glass and manufacturing efficiency. Typically, energy efficiency of glass furnaces offers major opportunities for manufacturing cost reduction.Significant rising of energy cost, environmental requirements for clean air and pressure for reducing global warming and carbon dioxide emissions, as well as the cost of capitals are main drivers for the technology developments. In this paper, energy efficiency of glass furnaces is discussed. Technology developments in selective batching, oxy-fuel firing with preheating batch and cullet, non-conventional advanced melting systems, such as segmented glass melting and submerged combustion melting, as well as using math modeling to optimize fuel distribution for energy savings are presented.

天然气铝熔炼炉内料堆熔化过程数值模拟与堆料高度优化研究

以天然气铝熔炼炉中铝料的熔化过程为研究对象,通过VOF模型捕捉气液界面,采用EnthalpyPorosity模型描述固液相变过程,对二维截面铝料熔化的非稳态过程进行数值模拟,研究铝料在熔化过程中的流动与传热行为,并对堆料方式单因素的影响进行分析。研究结果表明:在熔炼过程的前中期,熔化后的铝液累积在熔池烟气入口侧,导致已熔融铝液凝固;在铝料高度分别为2.94、2.64、2.34和2.04 m时,熔化速率随时间均呈现先减小后增大的规律;当料堆高度为2.64 m时,熔化时间最短,为3199 s,铝料平均温度最低,比基准工况下的平均温度低50 K,可以有效防止上层铝液过热,减少氧化造成的铸损。

基于Aspen Plus的MSW气化熔融工艺全流程模拟研究

城市固体废物(MSW)气化熔融工艺能够减少二噁英的生成和熔融固化重金属,是一种清洁高效的固体废物处理方式。已有研究多针对MSW的热解特性以及污染物的生成与排放,而对气化熔融工艺系统模块之间的影响和各反应器间物质流、能量流的联动变化过程研究不足。利用Aspen Plus模拟平台,基于吉布斯自由能最小化原理,对MSW气化熔融工艺进行了全流程模拟研究,分析了垃圾干燥温度、垃圾含水率、气化温度、气化介质以及灰熔点对工艺流程节点参数、物质流和能量流的影响,并提出了优化的工艺流程和运行参数。结果表明:在垃圾热解模拟时,垃圾含水率为9%,通过烟气循环能达到能量自给;在相同条件下,以水蒸气作为气化介质的气化效率最高,且在气化温度为850℃,水蒸气当量比为50%时,达到最佳工艺效果;当气化后产生的焦炭在熔融炉内燃烧刚满足灰熔点温度时,灰熔点的升高使气化剂比例、气化气有效气体摩尔流量和碳转化率不断降低。不同工况下的物质流、能量流的变化对实际工程具有指导意义。

铁浴条件下电炉粉尘球团的熔融与分离行为

为了提高对含锌电弧炉粉尘(EAFD)的利用效率,实验研究EAFD球团在铁浴条件下的还原熔化行为。定义铁液滴球形度作为判断其凝聚的标准,然后探讨铁液滴直径和球形度之间随时间变化的关系。根据实验最终建立EAFD颗粒的熔化和分离行为。结果表明,在铁浴条件下,EAFD球团的Zn去除率在5.0 min时达到99%以上,但在15.0 min时金属渣分离还没有完成。由于成分的波动,在EAFD球团中形成几个区域的液态渣,然后液态渣不断增加,直到球团完全熔化。球形度>65%、直径>500μm的Fe液滴的数量随着时间的推移而减少,大直径的Fe液滴先完成分离。渣铁分离过程如下:在布朗运动下Fe液滴在渣中形成,之后Fe液滴直径在马兰戈尼效应下增加,Fe液滴在渣中下降速度符合斯托克斯定律。