Yurii S. Semenov

This study presents a comprehensive analysis of the modeling and optimization of sensor installation nodes for weight measurement in the hoppers of a charging car utilized in coke production. The research highlights the critical role of precise load monitoring in preventing technological disruptions, minimizing equipment degradation, and optimizing energy consumption. Conventional sensor technologies, including capacitive, ultrasonic, and laser-based systems, are evaluated, with weight sensors mounted on hopper supports identified as the most robust solution for real-time mass determination under industrial conditions characterized by high dust levels, temperature fluctuations, and mechanical vibrations. A finite element analysis (FEA) was conducted to assess the structural behavior of sensor installation nodes under three distinct loading scenarios, corresponding to different operational conditions of the charging car. The four-point support structure of the hopper experienced the highest loads and non-uniformities. A stress–strain analysis of the sensor mounting assembly, performed using the Ansys software package, confirmed that both the sensor and its support structure maintain a sufficient safety margin (version 2024 R1, Ansys Inc., Canonsburg, PA, USA, the academic license provided to Wrocław University of Science and Technology). The findings validate the structural integrity and operational reliability of the proposed sensor configuration, contributing to the advancement of automated monitoring and control systems in coke production.

The article describes the problem of automated control of the quantitative distribution of the blast on the air tuyeres of a blast furnace (BF), which has been studied for many years and is still not fully resolved and relevant, since the uneven distribution of the blast significantly affects the gas distribution and thermal state throughout the volume of the BF. The results of the effectiveness of the application of the method of controlling the distribution of the blast parameters on the air tuyeres when manually measuring the thermal loads on the flanges of the suspended knees of the tuyere devices BF-1M and BF-12 of PrJSC "Kamet-steel" in 2018-2020 are shown. The methodological and information principles of the decision support system (DSS) for controlling the distribution of the blast parameters on the tuyeres of the BF, which has been developed in recent years at the Iron and Steel Institute, are presented. The creation of the DSS consists of the following stages: using information from modern automated control tools with the establishment of statistical dependencies of this information with blast smelting indicators; creation of a representative database containing various BF operating modes with corresponding technical and economic indicators of BF smelting, charging mode parameters and information on control means; development of a block of recommendations. DSS should include: visualization of primary information on the distribution of temperature differences and cooling water consumption around the circumference of the BF; visualization of calculated information on the distribution of the actual RAFT (raceway adiabatic flame temperature), consumption and blast speed, and the geometry of the raceway zone around the circumference of the BF; a block for generating recommendations on adjusting the consumption of fuel additives on individual tuyeres to ensure the required circumferential distribution of the RAFT; signaling on the presence of the so-called "slagging" of tuyeres; recommendations on changing the diameters of air tuyeres. DSS for controlling the circumferential distribution of blast parameters in a BF should also provide for the development of methods and criteria that allow for the synergistic interaction of the functioning of various DSSs installed on the BF. The article first shows the influence of the unevenness of the circumferential distribution of the thermal state of the lower zone of the BF, according to the distribution of the RAFT along the air tuyeres, on the development of the central gas distribution of the upper zone and the channel course of the BF, according to the readings of the means of controlling the temperatures of the gas flow above the charge surface. The dependences of the temperature indicators of the gas flow above the charge surface on the root mean square deviation of the RAFT along the circumference of the BF are obtained. The article indicates that an important stage in the development of the DSS is the testing of both its individual components and a set of recommendations for controlling BF smelting in real production conditions.

The article presents practical results of blast furnace (BF) smelting technology with pulverized coal injection (PCI) from various coal mixtures under conditions of variable coke quality. The effectiveness of using mixtures of lean and long-flame gas coal as part of PCI was investigated; lean coal of Australian, Czech, and North American origin and long-flame gas coal of Ukrainian origin were used. The periods of operation of three BFs in Ukraine were studied. The first two BFs (BF-A and BF-B) operated in similar technical and technological conditions with low coke quality with a hot strength index (CSR) of 45.4% and a specific PCI consumption of 86 kg/tHM. On average, the third BF (BF-C) operated in significantly better conditions during the experimental periods with a CSR of 61.1% and a specific PCI consumption of 145 kg/tHM. The actual coke replacement ratio with PCI was determined in comparison with the calculated replacement coefficients. For BF-A and BF-B, the actual coke replacement ratio of PCI, on average, was 0.75; for BF-C, it was 0.82. The results presented showed the advantages inherent in BF-C, compared to BF-A and BF-B, which are necessary to achieve the most efficient PCI: high-quality coke, a modern shaft cooling system, a dusting system using OXYCOAL technology, and distribution of charge materials using a bell-less top charging device. The paper shows the features of RAFT (Raceway adiabatic flame temperature) regulation when using different mixtures of PCI. Using the example of BF-A during four years of its operation, it is shown that obtaining minimum values of specific total fuel consumption, which characterize the reduction of the carbon footprint of BF technology, is possible both at PCI consumptions of 140–150 kg/tHM and at 80 kg/tHM, which is primarily due to the stable quality of coke and iron ore components of charge materials. The article presents recommended ranges of rational PCI consumption depending on the quality of coke. The dependence of the specific consumption of total fuel on the stability of the thermal state of BF smelting, which is estimated by the root-mean-square deviation of the silicon content in cast iron, is obtained, since ensuring a stable thermal state of BF smelting is an important component of effective PCI. The feasibility of improving the drainage capacity of the BF hearth under conditions of PCI when using coke of variable and low quality, which is ensured by introducing materials that are difficult to recover into the BF charge, is shown.

The article presents the results of studies of the circumferential gas distribution in a blast furnace using information on the distribution of the blast and modern control means performed on the blast furnaces of PrJSC "Kamet-steel". The constant and variable factors of influence on the unevenness of the blast flow rate along the circumference of the blast furnaces are highlighted. The main constant factors are the features and technical solutions of the hot blast supply tract, the location of the inlets and the design features of the lining of the inlet zone. The qualitative and quantitative influence of the blow supply units from the direct to the annular air duct, as well as the location of the cast-iron inlets for the modern operation of the blast furnaces of PrJSC "Kamet-steel" are determined. The main variable factors of influence on the unevenness of the blow flow rate are the technological and fuel and raw material conditions of the blast furnace smelting. The article develops a criterion for assessing the circumferential uniformity of the blast for periodic measurements of this unevenness, and also establishes correlations between the main gas-dynamic and temperature-thermal parameters of the tuyere zone, namely: the blast velocity at the tuyere exit, which reflects the actual volume of the blast passing through the cross-section of the air tuyere without taking into account the influence of the fuel supplied to the tuyere and without taking into account the influence of thermal radiation from the combustion chamber; the blast flow rate and the theoretical combustion temperature, which reflects the isothermal temperature-thermal balance of the tuyere zone, depending on the value of the coefficient of unevenness of the blast distribution across individual air tuyere for the operating conditions of the blast furnaces of PrJSC "Kamet-stal". The article establishes the relationship between the circumferential unevenness of the blow along the air tuyeres and the temperature of the peripheral gas flow and the relationship between the theoretical combustion temperature and the temperature indicators of the gas flow assessment above the surface of the charge, which characterize the development of the axial and peripheral gas flow, the gas permeability of the intermediate zone of the furnace top radius and the size of the axial vent. The multifactorial relationship between: blow – theoretical combustion temperature – the ratio of reduction in the "lower" and "upper" zones of the blast furnace – ore load is considered and analyzed, the need to comply with the conditions for burning fuel impurities to reduce the theoretical temperature and achieve the efficiency of blast furnace smelting is shown.

The article presents the main stages of developing a mathematical model of charging a blast furnace with a typical bell-type top charging device and creating the appropriate software. Based on the analysis of existing mathematical models and identification of their shortcomings, the approaches necessary for developing a mathematical model of charging adapted to the individual technological conditions of the blast furnace (BF-1M) of PrJSC “Kamet-steel” (Kamianske, Dnipropetrovsk Oblast, Ukraine) were formed. A study of the features of the formation of the backfill surface, characteristic of this type of charging devices, was conducted, which allowed us to reasonably determine the basic factors and initial conditions that affect the movement of charge materials. Based on the results obtained, algorithms for implementing the model were developed, which determine the sequence of actions to ensure the accuracy of calculations. The developed algorithms became the basis for creating software for a mathematical model of blast furnace charging using a bell-type charging device. The created software allows modeling blast furnace charging processes in various modes, including promising charging modes. The model testing confirmed its effectiveness in predicting the material distribution in the furnace, which contributes to the optimization of the blast furnace smelting process. The obtained results can be used to improve the technological charging modes and increase the efficiency of the blast furnace.

This article presents, for the first time in Ukraine, practical results of effective co-injection of pulverised coal (PCI) and natural gas (NG) into the hearth of a blast furnace (BF) under unstable charge and fuel conditions. Practical experiments have proven the maximum efficiency of such injection when fuel additives are injected onto separate lances into the blow channel of the tuyere device, and the NG lance is withdrawn so that its combustion occurs before the injection of PCI into the blow channel. In this case, maximum heating of PCI in the gas-air blast flow and its maximum burnout rate are achieved. The effectiveness of the practical application of the method of co-injecting PCI and NG into the hearth of a BF is expressed in a reduction in the specific coke consumption by 10.3 kg/ton of cast iron (or 2.85%) at a consumption of PCI – 153.4 kg/ton of cast iron and NG – 24.5 m ³ /ton of cast iron and the specific coke consumption by 2.4 kg/ton of cast iron (or 0.60%) with consumption of PCI – 108.9 kg/ton of cast iron and NG – 26.2 m ³ /ton of cast iron in conditions of co-injection not at all air tuyeres. The results obtained allow us to recommend this method of injecting fuel additives under acceptable price conditions, as well as at other metallurgical plants, especially those operating with better conditions for ensuring high temperatures of hot blast – more than 1050 °C.

This paper presents the results of the development of stabilization measures aimed at the removal of zinc with the products of melting and accumulation of titanium in the hearth of a blast furnace. The relevance of the development and use in practice of such measures is due to the unstable fuel and raw materials conditions for the production of cast iron, when their stabilization is a complex and difficult task, as well as the need to extend the campaign of blast furnaces during the overhaul period. The negative effect of zinc oxides on the condition of the blast furnace shaft lining, accompanied by slab formation, and the overconsumption of specific coke consumption, which occurs when zinc circulates in the volume of the blast furnace, require measures to remove zinc from the smelting products. The article proposes such measures, which consist of flushing according to the proposed schedule during the operation of the blast furnace at planned blowing parameters and with the provision of the necessary thermal reserve. In order to lengthen the campaign of a blast furnace, one of the most common methods for protecting the hearth lining is the periodic introduction of titanium‐containing materials into the charge of blast furnaces. The entry of titanium oxides into the furnace, as a rule, is ensured by the use of concentrate or specially prepared ilmenite briquettes with a high titanium content as part of the sinter charge, which can be introduced directly into the composition of the blast furnace charge. The article analyzes the experience of using titanium‐containing materials as part of a blast furnace charge and formulates measures to intensify skull formation in the hearth.