Еfficiency increase of powdered coal application at hot metal production and limestone calcination under unstable technology conditions

2020 ◽  
Vol 76 (7) ◽  
pp. 676-690
Author(s):  
Yu. S. Semenov ◽  
A. L. Podkorytov ◽  
V. V. Gorupakha ◽  
I. Yu. Semion ◽  
A. Yu. Orobtsev ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Ferrous Metallurgy ◽  
Gas Flow ◽  
High Efficiency ◽  
Furnace Productivity ◽  
Hot Metal ◽  
Coal Injection ◽  
Powdered Coal ◽  
Limestone Calcination ◽  
Steel Works

Operation of Ukraine ferrous metallurgy under conditions of dependence on import and instability of energy carriers supply, shortage of investments in modernization of production equipment, make the matter of cooperation between steel-works and research organization particularly actual. Basic results of cooperation between Z.I. Nekrasov Institute of Ferrous metallurgy, NAN of Ukraine and Dnepr steel-works in 2017–2019 on blast sfurnace operation pefection and technology of powdered coal injection into rotating limestone calcination furnaces. Results of the finding of the powdered coal optimal consumption shown, which ensure a high efficiency of the coke substitution, reaching of maximum possible blast furnace productivity as well as satisfactory utilization degree of the reducing gas ability. Results of implementation of a complex of measures presented, which ensure a rational distribution of the powdered coal by BF air tuyeres for making the heat conditions of the tuyere zone even by the blast furnace circle. Efficiency of application of technology of joint injection the powdered coal and natural gas was shown, which is achieved by improving the powdered coal combustion conditions in case of increase their mixing degree. Recommendations quoted for blast furnaces starting-up after their idling for a period exceeding the permissible one, without tapping the plug hot metal. The recommendations ensure an accident-free putting a blast furnace into operation followed by reaching planned parameters. Results of usage sensors information, measuring temperature of gas flow above the charge surface presented. The results allow to prove the correction of blast furnace charging mode by an expert module, generating correction impact to support control actions by technological personal. A complex of measures formed to prevent a disturbance of a blast furnace running in case of powdered coal injection in an amount exceeding 140 kg/t of hot metal and without application of special washover materials. The results of efficiency of the mastered technology, envisaging application manganese-bearing materials at a constant base, were shown. Results of diagnostics of workability of the facility for powdered coal injection into rotating limestone calcinating furnace presented, followed by elaboration recommendation on correction parameters of injection facility operation.

Technological advancements in evaluating the performance of the pulverized coal injection through tuyeres in blast furnace

2020 ◽  
Vol 117 (6) ◽  
pp. 611
Author(s):  
Ashish Agrawal ◽  
Rohit Kumar Tiwari ◽  
Sanjiv Kumar ◽  
Rajeswar Chatterjee ◽  
Basant Kumar Singh ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Pulverized Coal ◽  
Injection System ◽  
Metallurgical Coke ◽  
Hot Metal ◽  
Metal Production ◽  
Replacement Ratio ◽  
Pulverized Coal Injection ◽  
Factors Influencing ◽  
Coal Injection

The pulverized coal injection (PCI) is pursued to reduce the hot metal production cost by replacing the expensive metallurgical coke with the non-coking coal. Increasing the PCI rate causes various difficulties in the blast furnace (BF) operation. In the present work, an attempt is made to review the various aspects of PC injection in BF such as the challenges with increasing the PCI rate and modifications in the injection system to circumvent the concerns related to higher PCI rate. Various methods for detecting the tuyere blockage and failure caused due to the high PCI rate are elaborated. The factors influencing the combustion of coal in front of tuyeres have been discussed and their impact in the replacement ratio has been discussed. Further, recommendations are made to improve the coal combustibility in front of tuyeres.

Kinetics of limestone decomposition in hot metal

2018 ◽  
Vol 115 (6) ◽  
pp. 611 ◽  
Author(s):  
Biao Tang ◽  
Qifu Xiang ◽  
Jing Wang ◽  
Yunlong Zhang ◽  
Xingyi Li ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Heat Conduction ◽  
Cross Section ◽  
Gas Flow ◽  
Kinetic Equations ◽  
Product Layer ◽  
Hot Metal ◽  
Shrinking Core ◽  
Kinetics Of ◽  
Limestone Calcination

Compared with the traditional limestone calcination, this paper focuses on the conditions and temperature in hot metal where limestone calcines in converter steelmaking process. Considering heat transfer, mass transfer driven by concentration gradient and mass transfer (CO2 gas flow) driven by pressure gradient, macro kinetic models are established to describe limestone decomposition rate respectively. The method of rotating cylinder sample is used in the experiment of limestone decomposition in hot metal. The image processing software Image-Pro Plus is used to analyze the cross section of limestone calcined to get the unreacted core radius of cross section of cylindrical limestone. The results show that the decomposition mechanism of limestone follows the unreacted shrinking core model, the heat conduction of lime layer is the controlling step, the heat conduction and CO2 migration through the product layer determine the rate of limestone decomposition, and the corresponding kinetic equations are established.

Numerical Analysis of Flow Behavior Inside the Blast Furnace

2009 ◽  
Author(s):  
Dong Fu ◽  
Fengguo Tian ◽  
Guoheng Chen ◽  
D. Frank Huang ◽  
Chenn Q. Zhou
Keyword(s):  
Blast Furnace ◽  
Gas Flow ◽  
Cfd Simulation ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Furnace Productivity ◽  
Gas Distribution ◽  
Furnace Shaft ◽  
Parametric Studies ◽  
Flow Through

Gas and burden distributions inside a blast furnace play an important role in optimizing gas utilization versus the furnace productivity and minimizing the CO2 emission in steel industries. In this paper, a mathematical model is presented to describe the burden descent in the blast furnace shaft and gas distribution, with the alternative structure of coke and ore layers being considered. Multi-dimensional Ergun’s equation is solved with considering the turbulent compressible gas flow through the burden column. The porosity of each material will be treated as a function of three dimensional functions which will be determined by the kinetics sub-models accordingly. A detailed investigation of gas flow through the blast furnace will be conducted with the given initial burden profiles along with the effects of redistribution during burden descending. Also, parametric studies will be carried out to analyze the gas distribution cross the blast furnace under different cohesive zone (CZ) shapes, charging rate, and furnace top pressure. A good agreement was obtained between the CFD simulation and published experimental data. Based on the results, the inverse V shape is proved to be the most desirable CZ profile.

scholarly journals A Model to Control the Formation of Multi-Component Charge Portions on a Blast Furnace Conveyor

2020 ◽  
Vol 16 (6) ◽  
pp. 369-45
Author(s):  
M.O. Rybalchenko ◽  
◽  
A.M. Selegej ◽  
V.I. Golovko ◽  
S.M. Selegej ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Control System ◽  
Automatic Control ◽  
Gas Flow ◽  
Simulation Modelling ◽  
Charge Material ◽  
Furnace Productivity ◽  
Component Ratio ◽  
Maximum Output ◽  
Component Charge

Introduction. Bell-less tops used in the charging area give significantly wider opportunities for regulating and distributing the charge material along the furnace top radius. Moreover, it becomes feasible to develop the methods for gas flow control and these methods shall differ from the conventional ones. One of such methods is introduction of multi-component portions of the charge with a technology based component ratio. Problem Statement. The bell-less top charging device is not designed for that type of portioning when the charge material mixing is accompanied with a simultaneous shift of one component with respect to other one for a certain set value, while charging. These portions can be formed with the use of computer-aided stock-conveying system, while discharging the material from weighing hoppers into the blast furnace conveyor. Purpose. This research aims at the development of the structure, the functioning algorithms and the mathematical model for the system to control the formation of multi-component mixed charge batches in order to increase the blast furnace productivity and to reduce the specific coke consumption. Materials and Methods. In this research, the methods of automatic control theory and artificial intellect for the synthesis of weight neuro-fuzzy controllers within the automatic control system of charge dosage have been used. The developed system designed to control multi-component charge portioning via PC has been tested by means of simulation modelling methods. Results. There has been developed an algorithm for operating the system for controlling the multi-component mixed charge preparation on the conveyor, given the arrangement of the specified components, their ratios in portions, total volumetric productivity of the conveyor, the variable geometry of the unloaded material, in the connection with the on-line information on the mixing process. The feasibility of the system has been verified by its simulation with the use of standard application tools. Conclusions. It has been established that the designed control system allows the formation of mixed portions of any composition defined by an operator at a given maximum output of the conveyor and prevents its overload in terms of mass or volume.

scholarly journals A Model to Control the Formation of Multi-Component Charge Portions on a Blast Furnace Conveyor

2020 ◽  
Vol 16 (6) ◽  
pp. 36-45
Author(s):  
M.O. Rybalchenko ◽  
◽  
A.M. Selegej ◽  
V.I. Golovko ◽  
S.M. Selegej ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Control System ◽  
Automatic Control ◽  
Gas Flow ◽  
Simulation Modelling ◽  
Charge Material ◽  
Furnace Productivity ◽  
Component Ratio ◽  
Maximum Output ◽  
Component Charge

Introduction. Bell-less tops used in the charging area give significantly wider opportunities for regulating and distributing the charge material along the furnace top radius. Moreover, it becomes feasible to develop the methods for gas flow control and these methods shall differ from the conventional ones. One of such methods is introduction of multi-component portions of the charge with a technology based component ratio. Problem Statement. The bell-less top charging device is not designed for that type of portioning when the charge material mixing is accompanied with a simultaneous shift of one component with respect to other one for a certain set value, while charging. These portions can be formed with the use of computer-aided stock-conveying system, while discharging the material from weighing hoppers into the blast furnace conveyor. Purpose. This research aims at the development of the structure, the functioning algorithms and the mathematical model for the system to control the formation of multi-component mixed charge batches in order to increase the blast furnace productivity and to reduce the specific coke consumption. Materials and Methods. In this research, the methods of automatic control theory and artificial intellect for the synthesis of weight neuro-fuzzy controllers within the automatic control system of charge dosage have been used. The developed system designed to control multi-component charge portioning via PC has been tested by means of simulation modelling methods. Results. There has been developed an algorithm for operating the system for controlling the multi-component mixed charge preparation on the conveyor, given the arrangement of the specified components, their ratios in portions, total volumetric productivity of the conveyor, the variable geometry of the unloaded material, in the connection with the on-line information on the mixing process. The feasibility of the system has been verified by its simulation with the use of standard application tools. Conclusions. It has been established that the designed control system allows the formation of mixed portions of any composition defined by an operator at a given maximum output of the conveyor and prevents its overload in terms of mass or volume.

scholarly journals Numerical Analysis on Erosion and Optimization of a Blast Furnace Main Trough

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4851
Author(s):  
Hao Yao ◽  
Huiting Chen ◽  
Yao Ge ◽  
Han Wei ◽  
Ying Li ◽  
...  
Keyword(s):  
Blast Furnace ◽  
High Efficiency ◽  
Low Cost ◽  
Continuous Production ◽  
Hot Metal ◽  
Main Trough ◽  
Impact Position ◽  
Refractory Life ◽  
Volume Method ◽  
The Impact

The main trough of a blast furnace (BF) is a main passage for hot metal and molten slag transportation from the taphole to the torpedo and the slag handling. Its appropriate working status and controlled erosion ensure a safe, stable, high-efficiency and low-cost continuous production of hot metal. In this work, the tapping process of a main trough of a BF in the east of China was numerically studied with the help of a CFD library written in C++, called OpenFOAM, based on the use of the Finite Volume Method (FVM). The results show that turbulence intensity downstream of the hot metal impact position becomes weaker and the turbulence area becomes larger in the main trough. During the tapping, thermal stress of wall refractory reaches the maximum value of 1.7 × 107 Pa at the 4 m position in the main trough. Furthermore, baffles in the main trough placed between 5.8 m and 6.2 m were found to control and reduce the impact of the turbulence on the refractory life. The metal flowrate upstream of the baffles can be decreased by 6%, and the flow velocity on the upper sidewall and bottom wall decrease by 9% and 7%, respectively, compared with the base model. By using baffles, the minimum fatigue life of the refractory in the main trough increases by 15 tappings compared with the base model, so the period between the maintenance stops can be prolonged by about 2 days.

Influence of the prime hard coking coal in stamp charge cokemaking: true or false

2020 ◽  
Vol 117 (4) ◽  
pp. 412
Author(s):  
Hari Prakash Tiwari ◽  
Vishwesh M. Shisani ◽  
Bhavendra Kumar Sahu ◽  
Rabindra Kumar Sabat ◽  
Damodar Mittal
Keyword(s):  
Blast Furnace ◽  
Raw Material ◽  
Furnace Productivity ◽  
Specific Productivity ◽  
Hot Metal ◽  
High Quality ◽  
Coking Coal ◽  
Coal Blend ◽  
Working Volume

The production of hot metal through the blast furnace route is stilled the most cost-effective and highly productive process and probably remains the coming decades besides developed many alternative ironmaking technologies. In the recent past, the working volume of the blast furnace has been increased drastically to increase the blast furnace productivity. This means the blast furnace performance is more correlated to specific productivity which measures the efficiency in terms of ton hot metal. These modern blast furnaces favour high quality of coke, i.e. high coke CSR and M40 value, high iron content sinter and pellets. These high quality of input raw materials increased blast furnace efficiency and productivity. Generally, cokemakers increases the ratio of prime hard coking coal in the coal blend to achieve the high quality of coke. This increase in prime hard coking coal is not desirable for coke oven batteries because it creates high oven wall pressure and high coke cost and also not suitable for raw material security. The present investigation highlights few cases which clearly show that the high quality of coke (coke CSR: 69–71) may be easily produced with the optimal proportion of prime hard coking coal in the blend if the selection of coals is proper. Results confirmed that upto 30% primary hard coking coal with 15% non-coking coal in the coal blend produce an excellent quality of coke which naturally requires a careful selection on the blend component. The optimum composite coking potential (CCP) value of 4.6–4.9 is the ideal value for producing coke CSR in the range of 69–71 in recovery stamp charge cokemaking process in the real-time plant operation. Therefore, it is necessary to select the right coals for the coal blend based on the adopted cokemaking technologies to conserve the reserve of prime hard coking coal, oven health and cost-effectiveness.

Prediction of Blast Furnace Thermal State in Real-Time Operation

2020 ◽  
Vol 299 ◽  
pp. 518-523
Author(s):  
Nikolay Spirin ◽  
Oleg Onorin ◽  
Alexander Istomin
Keyword(s):  
Blast Furnace ◽  
Gas Flow ◽  
Thermal State ◽  
General Description ◽  
Blast Furnaces ◽  
Hot Metal ◽  
Blast Furnace Smelting ◽  
Transition Processes ◽  
Control Actions ◽  
Time Operation

The paper gives a general description of the dynamic model of the blast-furnace process that enables to calculate transition processes of the blast furnace thermal state, evaluated by the content of silicon in hot metal. It provides calculation results of the transition processes to be subjected to changes in control actions: ore load from the top and oxygen concentration in blast, natural gas flow rate and hot blast temperature from the bottom. Specific features of these transition processes during blast-furnace smelting are analyzed. The paper shows that the dynamic characteristics of blast furnaces change are subjected to control actions and depend significantly on properties of melted raw materials and operating parameters of blast furnaces. The oscillatory transition process in the blast furnace is observed in the case after disturbance it has an opposite influence on the thermal state of the lower and uppers stages of heat exchange. The paper presents prediction results of the silicon content in hot metal. It gives practical recommendations for selection of control actions.

scholarly journals Development and implementation of the new approaches to diagnostics and management of the blast furnace smelting

2019 ◽  
pp. 61-77
Author(s):  
Yu.S. Semenov ◽  
Е.І. Shumelchik ◽  
V.V Horupakha
Keyword(s):  
Blast Furnace ◽  
Gas Flow ◽  
Cooling System ◽  
Flame Temperature ◽  
Peripheral Zone ◽  
Pulverized Coal ◽  
Quantitative Composition ◽  
Blast Furnace Smelting ◽  
New Approaches ◽  
Steel Works

The article presents a brief description of the results of blast furnace production research carried out at the Yenakiieve Iron & Steel Works and the Dneprovsky Iron & Steel Integrated Works in 2011–2019. For the conditions of transition modes of blast furnace to ensure its stability in changing the qualitative and quantitative composition of the components of the charge materials, as well as in the change of fuel additives in the blast, the complex use of information of modern means of automated control is proved: stationary thermosets and thermocouples to the lining. New approaches to the choice of rational charging programs using the principle of variable maximum ore loading along the radius of the furnace within the charging cycle for working conditions on a charge of low quality have been developed. The implementation of such a charging program over the next three years has allowed to ensure a stable and economical course of melting, and its adaptation to the technology of using pulverized coal has allowed to reduce the gas flow temperature of the peripheral zone throughout the height of the blast furnace, as well as to preserve the cooling system during the development of lining-free. Expert module of adjustment of the program of charging using the established rational ranges of change of temperature indices of gas flow distribution along the radius of the furnace under different technological conditions of blast furnace has been developed and implemented on three blast furnaces. The method of reasonable choice of location of closed air tuyeres or air tuyeres of different diameter was developed and tested using information on change of lining temperatures on height and circumference of blast furnace. The method of equalizing the raceway adiabatic flame temperature around the blast furnace circumference by creating a non-uniform flow rate of pulverized coal in the air tuyeres has been improved and implemented. The basic technological requirements for blast furnace blasting after its long stop without release of "gantry" cast iron and scraping of materials from the furnace, the use of which before and in the blast furnace blasting of the Yenakiieve Iron & Steel Works and the Dneprovsky Iron & Steel Integrated Works after a long-lasting set-up were developed economic indicators, while ensuring the preservation of refractory lining, structures and equipment.

scholarly journals Experiments on Powdered Coal Injection into 0.5m3 Blast Furnace

1965 ◽  
Vol 5 (3) ◽  
pp. 180-186
Author(s):  
Mitsuru Tate ◽  
Chifu Nakane ◽  
Cheoul Woo Kim ◽  
Kichiya Suzuki
Keyword(s):  
Blast Furnace ◽  
Coal Injection ◽  
Powdered Coal
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