Burden Surface Research Articles

3-Dimension Burden Surface Imaging System with T-shaped MIMO Radar in the Blast Furnace

3-Dimension Burden Surface Imaging System with T-shaped MIMO Radar in the Blast Furnace

Blast furnace stockline measurement using radar

This paper presents a synergistic approach to stockline depth tracking within a blast furnace. Frequency modulated continuous wave (FMCW) radar can be used to measure the depth and surface profile of the burden surface; however, the radar signal is easily disturbed by radar anomalies during the process of continuous measurement. Data from the rotating chute and the charging signal provide information on the contextual relevance of these anomalies. An improved Kalman filter and anomaly detection model were developed to increase measurement accuracy by utilising contextual information. The approach was validated on production blast furnaces. The root mean squared (RMS) error in the measured depth was reduced by 17% when the proposed approach is used. The results suggest that this approach successfully adapts to changes in the pattern and characteristics of the burden surface.

Multi-Sensor Stockline Tracking within a Blast Furnace

The paper presents a synergistic approach for height tracking within a blast furnace (BF). The Frequency Modulated Continuous Wave (FMCW) radar has been employed to measure the height and surface profile of the burden surface. However the radar signal is easily disturbed, by the radar anomalies, during the process of continuous measurement. The data from rotating chute and charging switch provide information on contextual relevance with radar anomalies. An anomaly detection models has been developed to increase the measurement accuracy by utilizing contextual information. The approach has been validated on real BF. The root mean squared (RMS) error in the measured height is reduced by 17% when using the proposed approach compared to the case without it. The results suggest that the proposed approach successfully adapts to changes in the pattern and characteristics of the burden surface.

Three-Dimensional Modeling of Flow and Thermochemical Behavior in a Blast Furnace

An ironmaking blast furnace (BF) is a complex high-temperature moving bed reactor involving counter-, co- and cross-current flows of gas, liquid and solid, coupled with heat and mass exchange and chemical reactions. Two-dimensional (2D) models were widely used for understanding its internal state in the past. In this paper, a three-dimensional (3D) CFX-based mathematical model is developed for describing the internal state of a BF in terms of multiphase flow and the related thermochemical behavior, as well as process indicators. This model considers the intense interactions between gas, solid and liquid phases, and also their competition for the space. The model is applied to a BF covering from the burden surface at the top to the liquid surface in the hearth, where the raceway cavity is considered explicitly. The results show that the key in-furnace phenomena such as flow/temperature patterns and component distributions of solid, gas and liquid phases can be described and characterized in different regions inside the BF, including the gas and liquids flow circumferentially over the 3D raceway surface. The in-furnace distributions of key performance indicators such as reduction degree and gas utilization can also be predicted. This model offers a cost-effective tool to understand and control the complex BF flow and performance.

Multi-model control of blast furnace burden surface based on fuzzy SVM

Abstract Burden distribution is one of the key procedures of blast furnace operation. The improvement in control quality of the entire charging process for blast furnace is very necessary for more competitive and profitable production. In this paper, burden surface data from radars are classified by using k-means clustering algorithm to set up the multiple models set. Given objective burden surface, multiple burden distribution control strategies are obtained. In every charging period, real time burden surface data will be processed to match the model in model set by fuzzy support vector machine, and the optimal control strategy based on the matched model will be switched in action. Finally, blast furnace closed-loop control can be realized by this way. The proposed control method is applied to a blast furnace in an Iron and Steel Plant, energy saving and consumption reduction have been achieved greatly in this operation process.

Establish the multi-source data fusion model of the shape of blast furnace burden surface based on co-universal kriging estimation method

This paper presents a multi–source data fusion model method which could improve the blast furnace (BF) burden surface model accuracy. First, the three sections of straight line are used to describe the cross section of BF burden surface, and apply the motion law of the furnace burden to constrain the specific parameters of the three sections of straight line. Secondly, a multi–source data fusion method based on co–universal kriging estimation method is proposed. The temperature and height data are combined to build the unbiased estimation for the burden surface shape. Finally, an example of surface shape model using our proposed method in a 2500 m³ BF of a steel plant is discussed. The application shows that, contrasted with the traditional model, the model accuracy has arisen by 8%, and the resolution of surface shape has arisen by 0.32. The novel method can provide necessary guidance for energy saving and emission reduction in operation of the BF.

An Imaging Algorithm for Burden Surface with T-shaped MIMO Radar in the Blast Furnace

An Imaging Algorithm for Burden Surface with T-shaped MIMO Radar in the Blast Furnace

A Temperature Field Detection System for Blast Furnace Based on Multi-Source Information Fusion

With regard to the difficulty in detecting the burden surface temperature of blast furnace (BF), an online detection system based on multi-source information fusion is put forward in this paper. Firstly, a method for estimating the temperature of burden surface based on heterogeneous single information is proposed. Then an approach of multi-source information fusion based on reliability theory and Kalman Filter is presented. Lastly, the system implementation and industrial application is introduced. The result from a 2200 m3 BF indicates that this system can directly and accurately reflect the real-time state of burden surface temperature distribution. This paper provides an effective solution to control and monitor the process of complicated metallurgy.

Research on Image Acquisition and Data Transmission System of Burden Surface in Blast Furnace

As images of the burden surface are directly related to working status of the blast furnace, monitoring system of the burden surface is essential for blast furnace. Images of burden surface are captured by CCD camera, and then transmitted by video line through anti-interference devices and video capture card from top monitoring device located in furnace roof to the main monitoring room. The three environment parameters including nitrogen pressure, water pressure and working temperature of CCD camera are very important to ensure CCD camera working in good conditions. Pressure gauges for nitrogen and water are installed near top monitoring device; temperature sensor for CCD camera is installed in the top monitoring device. All environment parameters are transmitted by RS485 transmission lines and modbus protocol to be dealt with in the main monitoring room.

Design of Cooling System for Infrared CCD Camera Used to Monitor Burden Surface of Blast Furnace Based on Thermoelectric Coolers

A temperature control system based on thermoelectric coolers is designed in this paper for infrared CCD camera used to monitor burden surface of blast-furnace. The thermoelectric cooling system consists of a microcontroller module, a temperature sensor, a CCD camera, a thermoelectric cooler, a power amplifier and isolation module. The CCD camera with a temperature sensor is tightly mounted on the TEC cold surface. The microcontroller changes duty ratio of PWM signals with changes of the camera temperature to make working temperature of the CCD camera constant. The experiments show that the cooling system works well in temperature controlling

Particle Flow and Behavior at Bell‐Less Charging of the Blast Furnace

AbstractThe burden distribution in the upper part of the blast furnace is one of the most important factors controlling the gas flow distribution, and therefore the efficiency of heat and mass transfer and chemical reactions between gas and solids in the process. This work studies burden profiles formed by pellets and coke dumps using experiments and simulation. Comparing results from DEM simulation with findings from a small‐scale experimental system, it is demonstrated that the modeling technique is feasible. The rotation of the chute was found to cause a shift of the particles off from the bottom center line of the chute. In the burden layer formation, coke forms a pile at the intersection of falling trajectory and burden surface, while pellets spread towards the furnace center, simultaneously occupying the space between the larger coke particles after the pellet pile has reached the maximum natural angle. Particles with a high angular velocity were found to be more likely to enter the region close to the furnace wall. It is also shown that reducing the shear modulus of the burden material in the simulation is an efficient method to increase the calculating speed of the DEM without significant effect on the results of the simulation.

Experimental study of monodisperse granular flow through an inclined rotating chute

In blast furnaces, particles like coke, sinter and pellets enter from a hopper and are distributed on the burden surface by a rotating chute. Such particulate flows suffer occasionally from particle segregation during transportation caused by differences in density or size. To get a more fundamental insight into these effects, we started an experimental study to investigate the effect of rotation on such particulate flows. Here, as a first step, we present an experimental study of granular flow of monodisperse 3 mm spherical glass particles flowing with a constant mass rate through a rotating smooth rectangular chute, which is inclined at a fixed angle. Experiments are performed for a sufficiently long time to study steady (but streamwise accelerating) flow. Particle image velocimetry (PIV), electronic ultrasonic height sensors, and a dynamic weighing scale are used to measure the surface velocity of the particle stream, the particle bed height and mass flow rate in the chute, respectively. The influence of rotation speed and angle of inclination of the chute is studied. We find an interesting interplay between the Coriolis force, which pushes the granular flow to the sidewall of the chute and tends to diminish the acceleration of the flow, and centrifugal forces that accelerate the flow. The velocity components display a complex dependence on the spanwise and streamwise position in the chute. The bed height in the chute is also influenced by these effects of system rotation. These measurements provide a well-defined set of observations for refining and validating computer simulations of granular flows, and point out some important limitations of physical experiments. We present preliminary three-dimensional discrete particle simulations, which show that the experimental measurements of bed height and surface particle velocity in a chute inclined at 30° can be predicted nearly quantitatively both without and with rotation of the chute.

Simulation on the Burden Distribution by DEM

In this paper, a numerical simulation model based on discrete element method (DEM) has been developed to analyze the burden distribution in the Melter gasifier of COREX process. The burden trajectory, the location and the burden surface profile are analyzed in the top charging of melter gasifier. The distribution of ore and coke and the porosity in the radial direction are given under the different charging mode. The results can be used to optimize the charging patterns in order to obtain the reasonable gas distribution.

Mathematical Simulation of Burden Distribution in COREX Melter Gasifier by Discrete Element Method

COREX process is one of the earliest industrialized smelting reduction ironmaking technology. A numerical simulation model based on discrete element method (DEM) has been developed to analyze the burden distribution in the melter gasifier of COREX process. The DEM considering the collisions between particles can directly reproduce the charging process. The burden trajectory, the location and the burden surface profile are analyzed in melter gasifier with a mixing charging of coal and direct reduction iron (DRI) at the same time. Considering the porosity of packed bed has an important effect on the gas flow distribution of melter gasifier, a method to calculate porosity has been proposed. The distribution of DRI and coal and the porosity in the radial direction are given under different charging patterns, which is necessary to judge the gas flow distribution and provide base data for further researching the melter gasifier for the next work in the future. The research results can be used to guide the operation of adjusting charging and provide important basis for optimizing the charging patterns in order to obtain the reasonable gas distribution.

3-Dimension Imaging System of Burden Surface with 6-radars Array in a Blast Furnace

Harsh environment in Blast Furnace (BF) poses a big challenge for metallurgical industrial radar measurement of burden surface for ore and coke. The improved signal processing algorithm enhances the real-time performance. Antenna is specially designed for continuous stable signal acquirement, high temperature resistance and anti-dust ability. The experiment results illustrate that the single radar meets the accuracy requirement of solid bulk material. A new BF Burden Surface Measuring System is developed for real-time BF 3-D imaging. Distributed 6-radars array mounted on the top of 2500 m 3 BF. A virtual 3-D imaging is achieved with a reconstruction algorithm of 6-radars array according to the actual shape of BF. 3-D imaging system with 6-radars array provides an improved technique for intelligent control of burden distribution during BF iron making process.

Analysis of rapid flow of particles down and from an inclined chute using small scale experiments and discrete element simulation

In blast furnaces with bell-less charging systems, the particles enter the furnace from a hopper and are distributed on the burden surface by a rotating chute. The velocity distribution of the particles in the chute is known to affect the burden distribution and particle segregation on the burden surface. This paper investigates by simulating the translational and rotational velocity distributions of uniform spherical particles for the simplified cases where they are discharged from a hopper into a non-rotating chute set at different angles with respect to the vertical plane. The simulations, which are based on the discrete element method, are partly validated by small scale experiments, where particle velocities are estimated from observed trajectories of the particle stream leaving the chute, as well as by sampling particles in boxes to estimate the width of the stream. The simulated translational and rotational velocity distributions at different cross-sections of the chute for different tilting angles are also reported and discussed. The results show that the average velocity at the chute tip depends only on the chute angle for the bulk of the material flow. The angular velocity distribution of the particles along the cross-section of the chute exhibits a V shaped profile, while the opposite holds true for the translational velocity distribution. As the particles flow down the chute, both velocity distributions become more uniform.

Soft-sensing Method of Gas Flow Distribution of Blast Furnace Burden Surface Based on Multi-level Hierarchical Fusion Algorithm

Since the operation of blast furnace (BF) is closely related to the gas flow distribution in terms of stability, high production and low energy consumption, a soft-sensing method of gas flow distribution of BF burden surface based on multi-level hierarchical fusion is accordingly presented in order to solve the diffculty of direct detection for gas flow distribution. First, the multi-source information is registered to the same spatial dimension and temporal dimension. And then, the model of burden distribution and the model of burden surface temperature profile are respectively designed by means of data level fusion, which could reflect the gas distribution in the radial and axial directions. Finally, the gas flow distribution state is obtained by using the fuzzy decision level information fusion algorithm. According to the field simulation to verify the detection method, the method can accurately reflect the gas flow distribution of BF burden surface and offer a necessary guidance for the BF operation.

A Measuring System for Burden Surface Temperature Field of Blast Furnace

AbstractIt is important to measure the burden surface temperature of blast furnace (BF) since it can indicate the gas flow distribution and provide instruction for BF operation. The measuring system configuration based on multi-source information fusion is given in this paper to solve the problem of temperature filed measuring in BF. As a result, the multi-source information feature extraction and fusion methods are proposed. Finally, the methods proposed have been applyed to a 2200 m3 BF. Real runs of the measuring system show that the proposed measuring strategy can give good and visible measuring for burden surface temperature filed, which would be an effective method for controlling and monitoring in complicated metallurgy process.

Experimental study on the effects of blast‐cap configurations and charge patterns on coke descending in CDQ cooling shaft

AbstractThe coke descending behavior in a CDQ cooling shaft is studied experimentally by means of a tracing method with a digital camera. For three different blast‐caps, the law of coke flow is studied under five conditions of coke charge. The experimental results show that, for the sake of the uniformity of the coke burden descending, a blast‐cap with elliptical cross‐section is a better choice than that with circular cross‐section regardless of high or low placement. A coke charge pattern with a flat top burden surface is preferable to that with peak‐valley surface, a double‐peak superior to a one‐peak. Trajectory and average velocity distribution of coke behavior are depend weakly on whether the coke is continuously fed or not as the discharging began. The blast‐caps have local effects on the descending coke and hardly affect whether the cokes flow smoothly or not in the case of coke burden with enough depth. © 2008 Wiley Periodicals, Inc. Heat Trans Asian Res, 37(6): 352– 358, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/htj.20212

Model of Radial Distributions in the Upper Part of the Blast Furnace Shaft

A mathematical model is developed to estimate the radial distribution of the ore‐to‐coke ratio in the blast furnace shaft on the basis of molar flow and energy balance equations. It utilizes the radial temperature distribution of the gas measured above the burden surface to estimate the thermal flow ratios in concentric rings of the shaft, and from this the ore‐to‐coke distribution under the assumptions that a thermal reserve zone of a given temperature exists in the furnace. The model, which also predicts the radial distribution of temperature and pressure in the shaft, has been evaluated on measurements from an industrial blast furnace and verified by comparing the results with temperatures from an in‐burden probe.