Mathematical Modelling of Basic Oxygen Steel Making Process

A numerical model based on reaction the rmodynamics has been developed to simulate basic oxygen steel making process for predicting hot metal composition inside Linz-Donawitz (LD) converter with respect to blowing time. This mode l also contributes to-wards the prediction of sloping phenomenon taken place during basic oxygen steel mak-ing process. Modelling of basic oxygen steel making process has significant utility as productivity and lining life of Basic Oxygen Steelmaking(BOS)is highly dependable upon mass, momentum, energy transfer and rigorous interaction among metal,slag and gaseous phases. Comprehensive thermodynamic model of basic oxygen steel making pro-cess has been developed to predict the bath composition and temperature as well as de-carburization rate dynamically based on relevant blowing process parameters. One of the striking features of this developed model is the first time prediction of temperature vari-ation depending on evolving bath composition and generated heat from bath composition dependent feasible reactions and their extent. Moreover, this numerical model does not require off gas analysis to maintain its dynamic nature of prediction. A true attempt for the benefit of steel industry is made for predicting slopping initiation time for particular blowing condition based on correlation with model predicted decarburization rate and critical decarburization rate for bloating of metal droplet. In connection to that, formation of foamy slag and sloping possibility have been studied using thermodynamic modelling followed by multiphase computational fluid dynamics (CFD) simulation technique. The CFD simulation has been carried out taking different turbulence models along with vol-ume of fluid method (VOF) using ANSYS 15.0 software. CFD work demonstrates change in bath deformation profile during blowing period and also identifies the locations of dif-ferent vortexes formed owing to supersonic oxygen jet penetration. Dynamic mathemat-ical model of BOS has been interconnected with CFD simulation work for correlating fluid flow parameters with reaction behaviour inside BOS furnace. The results of devel-oped model has been comparedand validated with plant data. This work actually helps to understand basic oxygen steel making process in detail during the blowing period. De-veloped dynamic model can be used for LD converter having different capacities and accordingly this model’s application is very significant and wide in primary steel making are

Long-term diffusion factors of technological development - an evolutionary model and case study

In the first part of this article, a short description of the most popular models of two competing technologies (the Fisher-Pry model and its modifications proposed by Blackman, Floyd, Sharif and Kabir) and the multi technological substitution models of Peterka and Marchetti-Nakiæenoviæ are presented. In the second section, we describe an evolutionary model of diffusion processes based on biological analogy, together with the method of its parameters’ identification using real data on technologies development. In the final sections the applications of that model to describe the real diffusion processes (namely, primary energy sources in the world energy consumption and the raw steel production in the United States) are presented. The feasibility of using the model to predict future shares of given technologies and to build alternative scenarios of future evolution of structure of the market is suggested.diffusion; substitution; evolution; simulation; s-curve; logistic curve; logistic function

Computer modelling and analysis of particulate laden gas flows

This study is concerned with the prediction of the fluid-flow, chemical reactions and heat transfer processes in an industrial off-gas ducting system. A mathematical model is developed and then applied to predict the processes occurring in the off-gas ducting system. Particular attention is focussed on the two-phase thermal behaviour and the chemical reactions. A three-dimensional, two-phase numerical solution technique is used to solve the governing time-averaged partial differential equations. The model includes equations for turbulence, chemical reactions and two-phase thermal radiation. The calculations are performed for a particulate phase comprising non-reacting particles and a gaseous phase comprising chemically reacting gases. Both exothermic and endothermic reactions are considered. The effects of thermal radiation, particle solidification, chemical reactions and heat transfer on the two-phase flow are introduced and examined in detail. Predictions are made for an extensive range of parameters. The effects of these parameters on the off-gas ducting system are quantified. Comparisons are made between predicted results and experimental data when available and agreement is reasonable. The models developed can be easily incorporated into general-purpose fluid-flow packages. The procedure is general, and allows two-phase, two- or three-dimensional computations. Industrial plant can be modelled realistically on minicomputers at moderate costs. Convergence can normally be obtained with ease. It is concluded that for the cases studied, thermal radiation is a dominant factor in the calculation of the heat losses and that the particle contribution to these losses is small compared with that of the gases. The model indicates that the strongly temperature dependent reaction rates have a dominant influence in determining optimal operating conditions

Refining and Casting of Steel

Steel has become the most requested material all over the world during the rapid technological evolution of recent centuries. As our civilization grows and its technological development becomes connected with more demanding processes, it is more and more challenging to fit the required physical and mechanical properties for steel in its huge portfolio of grades for each steel producer. It is necessary to improve the refining and casting processes continuously to meet customer requirements and to lower the production costs to remain competitive. New challenges related to both the precise design of steel properties and reduction in production costs are combined with paying special attention to environmental protection. These contradictory demands are the theme of this book

Process Modeling in Pyrometallurgical Engineering

The Special Issue presents almost 40 papers on recent research in modeling of pyrometallurgical systems, including physical models, first-principles models, detailed CFD and DEM models as well as statistical models or models based on machine learning. The models cover the whole production chain from raw materials processing through the reduction and conversion unit processes to ladle treatment, casting, and rolling. The papers illustrate how models can be used for shedding light on complex and inaccessible processes characterized by high temperatures and hostile environment, in order to improve process performance, product quality, or yield and to reduce the requirements of virgin raw materials and to suppress harmful emissions

Dynamic model of basic oxygen steelmaking process based on multi-zone reaction kinetics : model derivation and validation

A multi-zone kinetic model coupled with a dynamic slag generation model was developed for the simulation of hot metal and slag composition during the BOF operation. The three reaction zones, (i) jet impact zone (ii) slag-bulk metal zone (iii) slag-metal-gas emulsion zone were considered for the calculation of overall refining kinetics. In the rate equations, the transient rate parameters were mathematically described as a function of process variables. A micro and macroscopic rate calculation methodology (micro-kinetics and macro-kinetics) were developed to estimate the total refining contributed by the recirculating metal droplets through the slag-metal emulsion zone. The micro-kinetics involves developing the rate equation for individual droplets in the emulsion. The mathematical models for the size distribution of initial droplets, kinetics of simultaneous refining of elements, the residence time in the emulsion, dynamic interfacial area change were established in the micro-kinetic model. In the macro-kinetics calculation, a droplet generation model was employed and the total amount of refining by emulsion was calculated by summing the refining from the entire population of returning droplets. A dynamic FetO generation model based on oxygen mass balance was developed and coupled with the multi-zone kinetic model. The effect of post combustion on the evolution of slag and metal composition was investigated. The model was applied to a 200-ton top blowing converter and the simulated value of metal and slag was found to be in good agreement with the measured data. The post-combustion ratio was found to be an important factor in controlling FetO content in the slag and the kinetics of Mn and P in a BOF process

Industrial Technology: Problem-Oriented Approach

The three problems -- operational control and management, research and development and design -- form the basis for increasing the efficiency of modern industrial technology and developing new one. The general approach to the development of the problem-oriented models has several particular features which depend on the problems to be solved: knowledge and data about the systems to be modeled, demand for model accuracy, type of model solution (off-line or on-line), computer type, etc. Different kinds of mathematical models which are implemented for operational control and management, research and development and design of a modern industrial technology -- steelmaking in basic oxygen furnaces (BOF) -- have been considered. The problems which were formulated, the approaches to the development of the mathematical models and the processes which occur in BOF technology, are typical for other different kinds of industrial technology, e.g. chemicals, cement industry, atomic reactors, glass industry