Some Aspects of the Control for the Radial Distribution of Burden Material and Gas Flow in the Blast Furnace

The paper presents an experimental study on the formation process of burden surface texture on the blast furnace throat and its influence on the radial distribution of gas flow. The study was performed with the application of blast furnaces equipped with a bell-type charging device using radio-isotope means for the control of burden surface texture (profile) and burden surface level, i.e., gamma locators for burden surface texture. The study was carried out under the conditions of an operating blast furnace in an iron and steel plant using a unique GEOTAPS system for automated control of geometric and temperature parameters of burden material surface on the blast furnace throat. The influence of the surface texture on the gas flow distribution was also investigated. The possibility of a self-stabilization effect for burden surface texture and gas flow in an operating blast furnace under suitable conditions was experimentally proven. As a result of the experimental study performed, four ways of energy-saving technology implementation were determined for the control of blast furnace melting based on the data on the burden surface texture and previously unknown regularities of surface layer formation of burden material on the throat of an operating blast furnace with a bell-type charging device. The main idea of the paper is the development of automated control for the radial distribution of burden material and gas flow using actual or predicted surface texture parameters as important intermediate factors that both describe the process and have a significant simultaneous influence on it.

Principal Component Analysis of Blast Furnace Drainage Patterns

Monitoring and control of the blast furnace hearth is critical to achieve the required production levels and adequate process operation, as well as to extend the campaign length. Because of the complexity of the draining, the outflows of iron and slag may progress in different ways during tapping in large blast furnaces. To categorize the hearth draining behavior, principal component analysis (PCA) was applied to two extensive sets of process data from an operating blast furnace with three tapholes in order to develop an interpretation of the outflow patterns. Representing the complex outflow patterns in low dimensions made it possible to study and illustrate the time evolution of the drainage, as well as to detect similarities and differences in the performance of the tapholes. The model was used to explain the observations of other variables and factors that are known to be affected by, or affect, the state of the hearth, such as stoppages, liquid levels, and tap duration.

Radar Detection-Based Modeling in a Blast Furnace: A Prediction Model of Burden Surface Descent Speed

The distribution of burden layers is a vital factor that affects the production of a blast furnace. Radars are advanced instruments that can provide the detection results of the burden surface shape inside a blast furnace in real time. To better estimate the burden layer thicknesses through improving the prediction accuracy of the burden descent during charging periods, an innovative data-driven model for predicting the distribution of the burden surface descent speed is proposed. The data adopted were from the detection results of an operating blast furnace, collected using a mechanical swing radar system. Under a kinematic continuum modeling mechanism, the proposed model adopts a linear combination of Gaussian radial basis functions to approximate the equivalent field of burden descent speed along the burden surface radius. A proof of the existence and uniqueness of the prediction solution is given to guarantee that the predicted radial profile of the burden surface can always be calculated numerically. Compared with the plain data-driven descriptive model, the proposed model has the ability to better characterize the variability in the radial distribution of burden descent speed. In addition, the proposed model provides prediction results of higher accuracy for both the future surface shape and descent speed distribution.

Automated Monitoring of Physical Processes of Formation of Burden Material Surface and Gas Flow in Blast Furnace

The paper is devoted to the issues of energy saving automatic control of radial burden distribution in the blast furnace throat. The main idea consists in control with prediction of the control resulting on the basis of automatic monitoring of burden surface texture. The paper develops the mathematic description of burden surface texture on the blast furnace throat by means of substantiation of minimum quantity of general indicators of the mixture being closely related to the main parameters of blast furnace processes. It is the first time that the optimum value of hoper depth in burden surface at 0.14 – 0.2 of throat diameter determined, the methods of its stabilization at the rate are substantiated, the new regularity of burden surface formation on the operating blast furnace throat is shown as consisting in the fact that the hoper depth on the surface is mainly changed responding the process of material charge rather than bulk material descent after the charge. It was also substantiated for the first time that radioisotopic methods for current control of burden distribution on the blast furnace throat provide timely formation of control actions for gas flow stabilization. The principle of self-tuning was theoretically substantiated for monitoring system of gamma profilometer responding to the monitoring conditions with respect to high penetration and random character of gamma rays. The principle enables significant improvement of accuracy, quick-response and radiological safety of gamma profilometer operation. The possibility of determination of burden surface texture on the throat of operating blast furnace and distribution of burden components according to infrared radiation of the surface without application of radiation hazardous monitoring means was proved for the first time.