Blast furnace charging optimization using multi-objective evolutionary and genetic algorithms

Charging programs giving rise to desired burden and gas distributions in the ironmaking blast furnace were detected through an evolutionary multi-objective optimization strategy. The Pareto optimality condition traditionally used in such studies was substituted by a recently developed k-optimality criterion that allowed for simultaneous optimization of a large number of objectives, leading to a significant improvement over the results of earlier studies. A large number of optimum charging strategies were identified through this procedure and thoroughly analyzed, in view of an efficient blast furnace operation.     

A review on nut coke utilisation in the ironmaking blast furnaces

In the ironmaking blast furnaces, nut coke (10–40 mm; 2–23?wt-%) is charged together with the ferrous burden. A systematic review is performed to understand the effects of nut coke use on the permeability, thermal reserve zone (TRZ), reduction kinetics and softening &; melting behaviour. State of the art techniques for enhancing reactivity and to lower TRZ temperature are discussed. To utilise nut coke effectively, need of correlational research is expressed on its behaviour with different burden chemistry, carbon ordering, ash content and distribution style. Challenges for higher nut coke utilisation like decrease in regular coke layer thickness and unconsumed fines in lower part of the furnace are pointed out. The scope of further research is marked via this review.

This review was submitted as part of the 2016 Materials Literature Review Prize of the Institute of Materials, Minerals and Mining run by the Editorial Board of MST. Sponsorship of the prize by TWI Ltd is gratefully acknowledged     

Motion trajectory mathematical model of burden flow at the top of bell-less blast furnace based on coordinate transformation

The motion trajectory mathematical model of burden flow is the basis for implementing blast furnace (BF) charging operation, which is of great significance for the stable and efficient operation of BFs. To calculate the motion trajectory of the burden flow at the top of the BF, static and dynamic coordinate systems are first established. Then, coordinate transformation and point composite motion methods are proposed and implemented to calculate this motion trajectory. Finally, the motion trajectories of the single-particle, multi-particle, and entire burden flows are analyzed and compared with the simulation results of a 1:8 scale BF discrete element method model. The results indicate that the absolute percentage errors (APEs) of the particle’s radial and Z-axis velocities are 7.89% and 4.65%, respectively, when the particle is at the chute tip in the single-particle flow trajectory. And the APEs of the radial and Z-axis velocities are 8.79% and 4.38%, respectively, when the burden flow is regarded as a particle. The foregoing demonstrates that the proposed mathematical model can effectively calculate the motion trajectory of the burden flow at the top of BF.     

A Genetic Algorithm Evolving Charging Programs in the Ironmaking Blast Furnace

In the ironmaking blast furnace, the distribution of the charged burden plays an important role because it influences the gas distribution in the shaft and the shape and the position of the cohesive zone. Because of enormous mechanical wear and high temperatures and pressure, the possibilities to reliably measure the distribution in real time are severely limited. Even though devices that provide information about the burden surface level have been developed, the high investment and maintenance costs make them economically infeasible in small or medium-size blast furnaces. A simplified first-principles model of the burden distribution forms the basis of the work presented in this article. A method is proposed by which a desired radial ore-to-coke distribution can be achieved by developing charging programs by a genetic algorithm, which was found to be a technique that can tackle this complex and nondifferentiable optimization problem. The algorithm evolves different charging programs subject to practical constraints of the charging (such as maximum skip size and movable armor spans), with the goal to find a charging program that minimizes the differences between the desired and calculated burden distribution. The article describes the method and presents a few illustrative examples on charging programs evolved by it.     

Mechanical properties of dusts collected from blast furnace dust catchers and cast house dedusting filters

ABSTRACT

Dust samples from blast furnace dust catchers and cast house dedusting systems were investigated with respect to flowability-relevant parameters. The mass median diameter of the dusts was in the range of 140 to 210 µm for the dust catcher dusts and approximately 6 µm for the cast house dusts. Generally, the flowability of the dust catcher dusts was better compared to the flowability of the cast house dusts. The flowability categories suggested by the three flowability indicators—the angle of repose, Hausner ratio, and Carr’s compressibility—were good for the coarser dusts, while for the finer dusts the flowability was overestimated. For the blast furnace dusts, from the dust catcher a considerable variation in the bulk density was found, which can presumably be attributed to the remarkable difference in the carbon content of the dusts investigated.     

基于ERP管理的高炉上料自动计量系统

文章介绍了高炉上料自动计量系统的信号采集、软件功能实现,以及如何利用网络、数据库等计算机技术实现远程数据管理,为企业的ERP系统提供实时数据。     

Effects of bottom base shapes on burden profiles and burden size distributions in the upper part of a COREX shaft furnace based on DEM

The shaft furnace plays a very important role in the quantity and quality indexes of the COREX process. However, research on burden distribution in the COREX shaft furnace is still immature and in need of further development and improvement. For instance, only a single ring charging process rather than multiple rings or a burden matrix process has been simulated for the shaft furnace in practical operation. Therefore, a three dimensional model of the upper part of COREX shaft furnace is developed in the present study. The model simulates the charging process with multiple rings and is then used to investigate the effects of different bottom base shapes on the burden profiles and radial size distributions. Results show that the last rings (the inner rings) in the burden matrix needs be carefully chosen, especially for the middle mode. The bottom base shape affects the burden size distribution a great deal but the surface burden profile very little at a fixed burden matrix. A bottom base of M shape is strongly recommended to obtain a uniform burden size distribution. The burden matrix and bottom base shape need to be well matched in order to obtain desired gas distributions.     

Effects of granulated blast furnace slag and superplasticizer type on the fresh properties and compressive strength of self-compacting concrete

This paper presents the results of an experimental investigation carried out to study the effect of granulated blast furnace slag and two types of superplasticizers on the properties of self-compacting concrete (SCC). In control SCC, cement was replaced with 10%, 15%, 20%, and 25% of blast furnace slag. Two types of superplasticizers: polycarboxylate based superplasticizer and naphthalene sulphonate based superplasticizers were used. Tests were conducted for slump flow, the modified slump test, V-Funnel, J-Ring, U-Box, and compressive strength. The results showed that polycarboxylate based superplasticizer concrete mixes give more workability and higher compressive strength, at all ages, than those with naphthalene sulphonate based superplasticizer. Inclusion of blast furnace slag by substitution to cement was found to be very beneficial to fresh self-compacting concrete. An improvement of workability was observed up to 20% of slag content with an optimum content of 15%. Workability retention of about 45 min with 15% and 20% of slag content was obtained using a polycarboxylate based superplasticizer; compressive strength decreased with the increase in slag content, as occurs for vibrated concrete, although at later ages the differences were small.     

提拉法单晶炉室与抽真空充气系统

炉室是单晶炉的中心环节,内置坩埚、晶体材料、加热系统和保温罩等.直拉法是在半导体领域中应用最广,产量最大的单晶制备方法.本文以提拉法单晶炉为例先介绍不同于其它设备的各种炉室结构、形状及原因,指出有关的附属结构.然后根据压力的不同对炉室进行了分类.最后详细论述了抽真空充气系统的综合方法及工作原理.     

Effect of particle shape on raceway size and pressure drop in a blast furnace: Experimental,numerical and theoretical analyses

Experiments and simulations are conducted to explore the changing laws of blast furnace (BF) raceway morphology and pressure drop with cylindrical particles. Experimental data show that there are five typical stages for the pressure drop during the raceway formation. The closer the aspect ratio (Ar) of the particle to 1, the bigger the raceway size and the wider the particle moving band will be. When the raceway is in stable stage, the pressure drop can be ascribed to the cooperative action of the bed height, inlet gas velocity and Ar. Numerical results reveal that the formation of large raceway for sphere-like particles is due to the small drag and contact forces. The contact forces in the prolate particle system are very large and thus result in a small raceway. Finally, the influence of particle shape is employed to improve a raceway size predictive correlation which can increase the average calculational accuracy by 3.4%.     

A data-driven surrogate-assisted evolutionary algorithm applied to a many-objective blast furnace optimization problem

A new data-driven reference vector-guided evolutionary algorithm has been successfully implemented to construct surrogate models for various objectives pertinent to an industrial blast furnace. A total of eight objectives have been modeled using the operational data of the furnace using 12 process variables identified through a principal component analysis and optimized simultaneously. The capability of this algorithm to handle a large number of objectives, which has been lacking earlier, results in a more efficient setting of the operational parameters of the furnace, leading to a precisely optimized hot metal production process.     

梯度涂层高炉风口的涂层梯度方程选择

采用有限元分析软件研究了具有不同梯度方程的梯度涂层高炉风口温度及应力的分布状况。结果表明：梯度涂层能够明显改变高炉风口的温度分布，缓和了涂层与基体接合界面处的应力。组成分布规律指数P=1时，涂层中应力缓和效果明显且应力值较小，从而确定最优涂层梯度方程为c=x／5。     

TDR—70A型单晶炉真空系统与空气系统设计

单晶炉是生长大规模集成电路所需要硅单晶的专用设备,本文主要介绍了单晶炉的真空系统与充气系统的设计。     

Evolutionary Neural Network Modeling of Blast Furnace Burden Distribution

A neural network-based model of the burden layer thickness in the blast furnace is presented. The model is based on layer thicknesses estimates from a single radar measurement of the burden (stock) level in the furnace and describes the dependence between the layer thickness and key charging variables. An evolutionary algorithm is applied to train the network weights and connectivity by optimizing the model structure and parameters simultaneously, tackling part of the parameter estimation by linear least squares. This enhances convergence and results in parsimonious and transparent network models with actions that can be explained. Finally, the networks are used in a hybrid model for analyzing novel charging programs and for studying the limits of the charging process.     

Multivariate process monitoring of an experimental blast furnace

Process monitoring by use of multivariate projection methods has received increasing attention as it can reduce the monitoring problem for richly instrumented industrial processes with many correlated variables. This article discusses the monitoring and control of a continuously operating experimental blast furnace (EBF). A case study outlines the need for monitoring and control of the EBF and the use of principal components (PCs) to monitor the thermal state of the process. The case study addresses design, testing and online application of PC models for process monitoring. The results show how the monitoring problem can be reduced to following just a few PCs instead of many original variables. The case study highlights the problem of multivariate monitoring of a process with frequently shifting operating modes and process drifts and stresses the choice of a good reference data set of ‘normal’ process behavior. Possible solutions for adaptations of the multivariate models to process changes are also discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

真空半连续热压炉控制系统的设计

介绍了真空半连续热压炉控制系统的设计方法，详细地论述了控制系统的硬件配置、软件设计。该控制系统实现如下功能：生产工艺设备运行状态工况显示及控制；现场实时监测数据显示及数字显示等。该方案具有硬件简单，使用灵活的特点，对中小型控制系统设计具有一定的参考价值。     

隧洞开挖光面爆破装药结构的改进与应用

为了解决乌干达卡鲁玛尾水隧洞光面爆破施工中,无专用光爆细药卷(φ20²2mm),且竹片难于买到,无法绑扎光爆药串等问题,在8#、9#、10#支洞及主洞开挖爆破施工中做了一系列光面爆破装药结构改进实验。采用(φ2522mm),且竹片难于买到,无法绑扎光爆药串等问题,在8#、9#、10#支洞及主洞开挖爆破施工中做了一系列光面爆破装药结构改进实验。采用(φ25³2mm)常规药卷,在其未与导爆索绑扎的条件下,导爆索成功起爆了光爆孔内按设计线装药密度装入的间隔装药,且取得了理想的光爆效果。实验及应用情况表明:在φ42mm光爆孔内,导爆索与一定间距(>50cm)的间隔装药在孔内自由分布、未绑扎的条件下,导爆索完全能够起爆孔内的间隔装药,这就简化了传统的光爆药串加工工艺,改变了隧洞开挖中传统的光爆孔内装药结构。     

隧洞开挖光面爆破装药结构的改进与应用

为了解决乌干达卡鲁玛尾水隧洞光面爆破施工中,无专用光爆细药卷(φ20~22mm),且竹片难于买到,无法绑扎光爆药串等问题,在8#、9#、10#支洞及主洞开挖爆破施工中做了一系列光面爆破装药结构改进实验。采用(φ25~32mm)常规药卷,在其未与导爆索绑扎的条件下,导爆索成功起爆了光爆孔内按设计线装药密度装入的间隔装药,且取得了理想的光爆效果。实验及应用情况表明:在φ42mm光爆孔内,导爆索与一定间距(50cm)的间隔装药在孔内自由分布、未绑扎的条件下,导爆索完全能够起爆孔内的间隔装药,这就简化了传统的光爆药串加工工艺,改变了隧洞开挖中传统的光爆孔内装药结构。     

双炉体真空烧结炉报警系统设计

本文分析了几种真空烧结炉常见的报警量,并给出了工程解决方案.在真空炉控制系统中合理利用报警量,可以有效提高人员和设备的安全性.     

含钛高炉渣催化剂的光催化活性

以攀钢含钛高炉废渣为原料,在不同温度下煅烧合成了钙钛矿型硫酸掺杂的含钛高炉渣催化剂(sulfuric acid-modified titanium-bearing blast furnace slag,STBBFS),研究了混晶结构和硫掺杂对含钛高炉渣光催化活性的影响,结果表明,含钛高炉渣催化剂具有钙钛矿/锐钛矿混晶结构,粉体的颗粒形状不规则,煅烧后粒径变大;在紫外区域具有很强的光吸收能力,STBBFS催化剂的光催化活性由Cr(Ⅵ)的还原率评价.煅烧温度为400℃时,STBBFS催化剂的表面存在含量较高的SO2-4和较高的CaTiO3/TiO2晶相比,具有较高的光催化活性,用500 W中压汞灯照射10 h,可将浓度为20 mg·L-1的六价铬废水完全降解.