495 research outputs found
Fuzzy Expert System To Predict Maintenance Intervals In A Continuous Caster
No full textThis paper was published at the CPC-93 International Conference on Computerized Production Control in Steel Plants, Seoul, Korea, Nov. 1993. KEYWORDS Expert system; fuzzy logic; maintenance; steel production; quality; scheduling; continuous caster; AI and knowledge-based systems; uncertainty management
Heat transfer in a continuous bloomcaster
No full textFour approaches to detecting disruptions to the primary cooling process in the continuous bloomcaster at BHP's Rod and Bar Division in Newcastle are investigated. Three of these are based on heat conduction models of the mould. A one-dimensional steady-state formulation leads to the conclusion that it may not be possible to detect changes in the length of the lubricating flux layer between the solidifying steel strand and the mould from data collected at thermocouples in the mould. Two two-dimensional models give formal procedures for determining either the heat input to the mould or the presence of hot spots in the strand from the thermocouple data. The final approach suggests the use of time-series analysis to detect changes in the heat transfer process
Semi-continuous caster for plate
No full textPurpose: Development of a semi-continuous caster that can cast a single plate and
a clad plate of Al-40%Sn-1%Cu alloy used for sliding bearings.
Design/methodology/approach: A semi-continuous caster to cast a single plate and
a clad plate directly from molten metal was designed and assembled. The cast single
plate has a thickness ranging from 10 mm to 30 mm, a width of 400 mm, and a length of
500 mm to 1,000 mm. The cast clad plate has a thickness ranging from 10 mm to 30 mm,
a width of 50 mm, and a length of 300 mm.
Findings: The semi-continuous caster successfully produced both a single plate and a
clad plate of Al-40%Sn-1%Cu alloy. Influence of casting conditions on the properties of
the plate, including the thickness, porosity, and surface quality were investigated in the
single plate casting. The mixing and diffusion of the alloy elements at the interface was
also investigated in the clad plate casting.
Research limitations/implications: The cast Al-40%Sn-1%Cu alloy plate has not
yet been tested as a sliding bearing material, so the efficacy of the material still requires
investigation.
Practical implications: The semi-continuous caster described in this paper enables the
“small lot” production made from single and clad plates of aluminium alloy.
Originality/value: Development of a semi-continuous caster that can cast both single
and clad plates of aluminium alloy. Investigation of the relationship between the casting
conditions and plate quality.
</jats:p
Contract net protocol for cooperative optimisation and dynamic scheduling of steel production
No full textSemi-Continuous Caster for an Aluminum Alloy Plate
No full textTwo types of side dams for a semi-continuous caster, a thin steel plate and a deformable fence, were developed and tested. The semi-continuous caster equipped with deformable side dam fences was found to be superior. The deformable side dam fences were set between the substrate and the roll. Molten metal was solidified by the lower substrate and the upper roll. A 10-mm-thick 1200 aluminum alloy plate was cast at 1 m/min. The deformable side dam fences were effective at providing plate reduction and ensuring a flat upper surface.</jats:p
Desenvolvimento de um procedimento computacional para o estudo do escoamento no interior de distribuidores de lingotamento contínuo
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-graduação em Engenharia Mecânica, Florianópolis, 2010O presente trabalho visa o estudo e validação de modelos numéricos que permitam avaliar o escoamento no interior de distribuidores de lingotamento contínuo dado um conjunto de configurações de modificadores de fluxo - inibidores, diques, barreiras e injeção de gás. O objetivo é desenvolver através da simulação numérica, novas metodologias que auxiliem ao projeto e à predição do desempenho dos produtos refratários desenvolvidos na empresa Magnesita. Para o estudo numérico foi empregado o pacote comercial ANSYS CFX®. O CFX é um código de Dinâmica dos Fluidos Computacional, desenvolvido pela empresa ANSYS, Inc., baseado na técnica dos volumes finitos baseados em elementos, que utiliza um solver acoplado. Para a modelagem do escoamento no interior do distribuidor, iniciaram-se as atividades realizando validações entre o modelo numérico desenvolvido e modelos físicos para configurações com barreiras e inibidores de turbulência. Dessa forma, nessa primeira etapa foi considerado um escoamento monofásico de água, tridimensional, permanente e turbulento. A validação é realizada comparando as curvas de Distribuição de Tempos de Residência, calculadas através da injeção e monitoramento da concentração de um traçador no interior do distribuidor, e de volumes e tempos característicos. Na sequência, avaliou-se o escoamento multifásico, considerando assim a injeção de gás no interior do distribuidor. Nessa etapa foram considerados não somente as curvas características, mas também uma validação em relação à remoção de inclusões no distribuidor através da formulação Lagrangeana. O trabalho transfere, em termos de metodologia numérica, importante tecnologia para as indústrias que fabricam distribuidores empregados em lingotamento contínuo.This work presents a study and numerical models validation that permits evaluate the flow inside a tundish configuration implemented by flow modifiers. The goal is to use the computational simulation to develop new approaches that help to design and increase the performance of the refractory products developed in the company Magnesita. The numerical models have been performed with the help of the commercial CFD code ANSYS CFX®, which employs the Element Based Finite Volume Method to solve the conservation equations in the proper domain. At the first step, it was performed the validation among numerical and experimental results for a tundish composed with dams and turbulence inhibitors, considering a single-phase flow of water, three dimensional, permanent and turbulent model. The model has been validated through a comparison of the Residence Time Distribution, the volumes and times characteristics. In a second step, a multiphase flow computational model of gas injection inside a tundish has been developed and validated with experimental data. The model has been validated through a comparison of Residence Time Distribution and inclusion removal analysis through the Lagrangian formulation with experimental measurements. The work provides an important technology in terms of numerical methodology in the tundish projects
Liquid Core Detection and Strand Condition Monitoring in a Continuous Caster Using Optical Fiber
No full textReal-time monitoring of the liquid core position during the continuous casting of steel has been demonstrated using low-cost distributed optical-fiber-based strain sensors. These sensors were installed on the containment roll support structures in the segments of a production continuous caster to detect the position of the solid–liquid interface and monitor the strand condition during the continuous casting. Distributed Fiber Bragg Grating sensors (FBGs) were used in this work to monitor strain at six roll positions in the caster. The sensor performance was first validated by comparing optical strain measurements with conventional strain gauge measurements in the lab. Next, optical strain measurements were performed on an isolated caster segment in a segment maintenance facility using hydraulic jacks to simulate the presence of a liquid core under the roll. Finally, the sensors were evaluated during caster operation. The sensors successfully detected the load increase associated with the presence of a liquid core under each instrumented roll location. Incidents of bulging and roll eccentricity were also detected using frequency analysis of the optical strain signal. The liquid core position measurements were compared using predictions from computer models (digital twins) in use at the production site. The measurements were in good agreement with the model predictions, with a few exceptions. Under certain transient caster operating conditions, such as spraying practice changes and SEN exchanges, the model predictions deviated slightly from the liquid core position determined from strain measurements
Optical Sensor Instrumentation for Enhanced Continuous Caster Development
No full textFiber-optic sensors are an emerging technology that can enhance process monitoring and control in steelmaking. They are especially valuable in the continuous caster’s harsh environment. This dissertation presents the industrial application and demonstration of three sensor types: single-mode silica fiber with Rayleigh-based Optical Frequency Domain Reflectometry (OFDR), sapphire fiber (single-crystal alumina) with Fiber Bragg Gratings (sFBG), and an in-line Raman spectroscopy probe. Each sensor served a distinct role in the continuous caster. Rayleigh OFDR sensors were embedded in tundishes for distributed thermal mapping at 7-mm spatial resolution across ≈4 m. Measurements were taken during preheating, casting, and ladle exchanges, and they revealed refractory dry-out and nonuniform heating, consistent with steam buildup and possible hydrogen ingress. A sapphire FBG probe, with three FBGs over 38 cm, provided thermal profiling of the tundish bath and the approximate slag–metal interface during long casting sequences. This detected level changes and thermal stratification (readings ≈7 in. deeper were ~10–15 °F hotter than the operator thermocouple depth). A sapphire FBG was embedded in the sidewall of a submerged entry nozzle (SEN) and captured axial temperature gradients during preheating. A Raman fiber probe collected spectra for high-temperature flux analysis near 1400 °C in the mold. These industrial trials demonstrated sensor packaging, survivability, and process-relevant signal measurements in continuous-caster production environments. Integrating these sensors in the continuous caster revealed new signals for future control and monitoring and advanced real-time process awareness in steel manufacturing
Continuous slab caster scheduling and interval graphs
No full textWe define and solve a scheduling problem for operating the continuous steel slab caster which converts molten steel into slabs. The nature of our problem has an interesting connection to a special class of graphs known as interval graphs. We show that our problem can be seen as a variant of the clique partitioning problem defined on interval graphs and develop an optimal algorithm for it.X1112sciescopu
Continuous caster scheduling, an optimization approach using column generation
No full textgrantor:
University of TorontoScheduling of certain major production operations remains a chronic concern for integrated steel producers. One operation in particular, the twin strand Continuous Slab Caster, is a major contributor to overall plant profitability when utilized effectively. In this thesis, we describe the optimization based heuristic that has been implemented to support Continuous Caster scheduling needs at Dofasco Inc. (Hamilton, Ontario, Canada). The basic scheduling problem addressed is a variation of the multiple Travelling Salesman Problem with competing objectives and complex, cross tour synchronization constraints. An integer programming formulation for this scheduling problem is presented and a decomposition and column generation based heuristic solution strategy is described. The quality of the heuristic model is evaluated using statistical methods for optimal solution value estimation. In addition, economic benefits of using this approach, estimated at $1.7 million per year, are developed from direct comparison with real production schedules, using actual production system measures.Ph.D
- …
