scholarly journals Evaluation of the Influences of Scrap Melting and Dissolution during Dynamic Linz–Donawitz (LD) Converter Modelling

Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 186 ◽  
Author(s):  
Florian Penz ◽  
Johannes Schenk ◽  
Rainer Ammer ◽  
Gerald Klösch ◽  
Krzysztof Pastucha
Keyword(s):  
Process Model ◽  
Research Work ◽  
Bath Temperature ◽  
Melting Behavior ◽  
Pure Oxygen ◽  
Dissolution Behavior ◽  
Special Focus ◽  
Hot Metal ◽  
Crude Steel ◽  
Scrap Melting

The Linz–Donawitz (LD) converter is still the dominant process for converting hot metal into crude steel with the help of technically pure oxygen. Beside hot metal, scrap is the most important charging material which acts as an additional iron source and coolant. Because of the irrevocable importance of the process, there is continued interest in a dynamic simulation of the LD process, especially regarding the savings of material and process costs with optimized process times. Based on a thermodynamic and kinetic Matlab® coded model, the influences of several scrap parameters on its melting and dissolution behavior were determined, with a special focus on establishing the importance of specific factors on the crude steel composition and bath temperature after a defined blowing period to increase the accuracy of the process model. The calculations reported clearly indicate that the dynamic converter model reacts very sensitively to the chemical composition of the scrap as well as the charged scrap mass and size. Those results reflect the importance of experiments for validation on the diffusive scrap melting model in further research work. Based on that, reliable conclusions could be drawn to improve the theoretical and practical description of the dissolution and melting behavior of scrap in dynamic converter modelling.

scholarly journals Numerical Simulation of the Melting Behavior of Steel Scrap in Hot Metal

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 678
Author(s):  
Nanyang Deng ◽  
Xiaobin Zhou ◽  
Moer Zhou ◽  
Shiheng Peng
Keyword(s):  
Carbon Concentration ◽  
Vertical Direction ◽  
Bath Temperature ◽  
Melting Behavior ◽  
Melting Rate ◽  
Middle Part ◽  
Steel Scrap ◽  
Low Carbon ◽  
Carbon Distribution ◽  
Hot Metal

The current study focuses on the melting behavior of a scrap bar with low carbon content in hot metal which contains high carbon concentration by applying experiments and mathematical modelings. The experiments suggest that higher temperature is favorable for the melting of the bar and the melting rate of the bar is initially high while decreased to a relative stable level after 90 s in the current conditions. It can be found from the mathematical results that the bar temperature is increased near to bath temperature in about 20 s after it was immersed into the bath, and the temperature in the axis of the bar is not distributed evenly during the temperature increase stage. Moreover, the mathematical results shows that a bath circulation flow would be formed in the bath under the effects of temperature and carbon distribution during the melting process. The bath flow near the melting interface would influence the carbon concentration of the molten phase, in turn, affects the melting rate of the bar in the vertical direction. Both the experimental and mathematical results show that the melting rate in the upper part, which is in the upstream of the bath flow, is higher than that of the middle part, followed by the down part of the bar in the downstream of the flow, in which the carbon concentration is much lower than that of the bath. At this period, the main factor that dominate the bar melting is not the temperature but the carbon distribution at the melting interface after the bar temperature is increased to the bath temperature.

scholarly journals Scrap melting model for steel converter founded on interfacial solid/liquid phenomena

2017 ◽  
Vol 115 (2) ◽  
pp. 201 ◽  
Author(s):  
Ari Kruskopf ◽  
Lauri Holappa
Keyword(s):  
Mass Transfer ◽  
Process Model ◽  
Melting Rate ◽  
Phase Changes ◽  
Interface Model ◽  
Hot Metal ◽  
Scrap Melting ◽  
Carbon Mass ◽  
Steel Converter ◽  
Solid Liquid

The primary goal in steel converter operation is the removal of carbon from the hot metal. This is achieved by blowing oxygen into the melt. The oxidation of carbon produces a lot of heat. To avoid too high temperatures in the melt cold scrap (recycled steel) is charged into the converter. The melting rate is affected by heat and carbon mass transfer. A process model for steel converter is in development. This model is divided into several modules, which are fluid dynamics, heat- and mass-transfer, scrap melting and chemical reactions. This article focuses on the development of the scrap melting module. A numerical model for calculating temperature and carbon concentration in the melt is presented. The melt model is connected with the solid scrap model via solid/liquid interface. The interface model can take into account solidification of iron melt, melting of solidified layer, a situation without such phase changes, and scrap melting. The aim is to predict the melting rate of the scrap including the properties of the hot metal. The model is tested by calculating the melting rates for different scrap thicknesses. All of the stages in the interface model were taking place in the test calculations.

scholarly journals Towards CRISP-ML(Q): A Machine Learning Process Model with Quality Assurance Methodology

2021 ◽  
Vol 3 (2) ◽  
pp. 392-413
Author(s):  
Stefan Studer ◽  
Thanh Binh Bui ◽  
Christian Drescher ◽  
Alexander Hanuschkin ◽  
Ludwig Winkler ◽  
...  
Keyword(s):  
Machine Learning ◽  
Quality Assurance ◽  
Process Model ◽  
Practical Experience ◽  
Special Focus ◽  
Close Monitoring ◽  
Machine Learning Applications ◽  
Project Organizations ◽  
Considerable Impact ◽  
Learning Development

Machine learning is an established and frequently used technique in industry and academia, but a standard process model to improve success and efficiency of machine learning applications is still missing. Project organizations and machine learning practitioners face manifold challenges and risks when developing machine learning applications and have a need for guidance to meet business expectations. This paper therefore proposes a process model for the development of machine learning applications, covering six phases from defining the scope to maintaining the deployed machine learning application. Business and data understanding are executed simultaneously in the first phase, as both have considerable impact on the feasibility of the project. The next phases are comprised of data preparation, modeling, evaluation, and deployment. Special focus is applied to the last phase, as a model running in changing real-time environments requires close monitoring and maintenance to reduce the risk of performance degradation over time. With each task of the process, this work proposes quality assurance methodology that is suitable to address challenges in machine learning development that are identified in the form of risks. The methodology is drawn from practical experience and scientific literature, and has proven to be general and stable. The process model expands on CRISP-DM, a data mining process model that enjoys strong industry support, but fails to address machine learning specific tasks. The presented work proposes an industry- and application-neutral process model tailored for machine learning applications with a focus on technical tasks for quality assurance.

scholarly journals Special Focus: The Use of Emerging Technologies on the Internet of Everything

2017 ◽  
Vol 11 (5) ◽  
pp. 4
Author(s):  
Alberto Cardoso ◽  
Maria Teresa Restivo ◽  
Hélia Guerra ◽  
Luís Brito Palma
Keyword(s):  
Emerging Technologies ◽  
International Workshop ◽  
Research Work ◽  
Mobile Technologies ◽  
The Internet ◽  
Special Focus ◽  
Application Development ◽  
Internet Of Everything ◽  
Technology Applications ◽  
Interdisciplinary Concept

The Internet of Everything is an interdisciplinary concept that involves technology, applications and people in a framework where emerging technologies can give a relevant contribute in education and in different application areas, namely in the scope of the interactive mobile technologies. This Special Issue collects a set of contributions to this topic resulting from the works presented in the Experiment@ International Workshop 2016 “The Emerging Technologies on the Internet of Everything” – ETIoE’16, held at University of the Azores (Ponta Delgada, Azores, Portugal). These articles comprise different perspectives in this field from research work and application development to case studies.

Ontology-Based Framework for Quality in Configurable Process Models

2020 ◽  
pp. 464-478
Author(s):  
Loubna El Faquih ◽  
Mounia Fredj
Keyword(s):  
Business Process ◽  
Process Modeling ◽  
Process Model ◽  
Business Processes ◽  
Research Work ◽  
Process Models ◽  
Novel Method ◽  
Ontology Languages ◽  
Variability Management

In recent years, business process modeling has increasingly drawn the attention of enterprises. As a result of the wide use of business processes, redundancy problems have arisen and researchers introduced the variability management, in order to enhance the business process reuse. The most approach used in this context is the Configurable Process Model solution, which consists in representing the variable and the fixed parts together in a unique model. Due to the increasing number of variants, the configurable models become complex and incomprehensible, and their quality is therefore impacted. Most of research work is limited to the syntactic quality of process variants. The approach presented in this paper aims at providing a novel method towards syntactic verification and semantic validation of configurable process models based on ontology languages. We define validation rules for assessing the quality of configurable process models. An example in the e-healthcare domain illustrates the main steps of our approach.

scholarly journals Diffusive steel scrap melting in carbon-saturated hot metal—phenomenological investigation at the solid–liquid interface

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1358 ◽  
Author(s):  
Penz ◽  
Schenk ◽  
Ammer ◽  
Klösch ◽  
Pastucha ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Carbon Concentration ◽  
Steel Production ◽  
Production Optimization ◽  
Steel Scrap ◽  
Process Conditions ◽  
Hot Metal ◽  
Scrap Melting ◽  
Solid Liquid Interface ◽  
Solid Liquid

The oxygen steelmaking process in a Linz-Donawitz (LD) converter is responsible for more than 70% of annual crude steel production. Optimization of the process control and numerical simulation of the LD converter are some of the current challenges in ferrous metallurgical research. Because of the process conditions and oxidation of impurities of the hot metal, a lot of chemical heat is generated. Therefore, steel scrap is charged as a coolant with the economical side aspect of its recycling. One of the more complex aspects is, among others, the dissolution and melting behaviour of the scrap in carbon-saturated hot metal. Heat and mass transfer act simultaneously, which has already been investigated by several researchers using different experimental approaches. The appearances at the interface between solid steel and liquid hot metal during diffusive scrap melting have been described theoretically but never investigated in detail. After an experimental investigation under natural and forced convective conditions, the samples were further investigated with optical microscopy and electron probe microanalysis (EPMA). A steep carbon concentration gradient in the liquid appeared, which started at an interface carbon concentration equal to the concentration on the solid side of the interface. Moreover, the boundary layer thickness moved towards zero, which symbolized that the boundary layer theory based on thermodynamic equilibrium was not valid. This fact was concluded through the prevailing dynamic conditions formed by natural and forced convection.

INNOVATIVE FORMING TECHNOLOGY AS A KEY FOR THE EFFECTIVE MANUFACTURING OF LIGHTWEIGHT STRUCTURES

2008 ◽  
Vol 07 (01) ◽  
pp. 37-40
Author(s):  
ERMAN TEKKAYA ◽  
MICHAEL TROMPETER ◽  
WERNER HOMBERG
Keyword(s):  
Sheet Metal ◽  
Traffic Engineering ◽  
Research Work ◽  
High Strength ◽  
Special Focus ◽  
Lightweight Construction ◽  
Lightweight Structures ◽  
Forming Technology ◽  
The Face ◽  
Volume Production

Current tends in car body or rail traffic engineering aim at the realization of modern lightweight structures. In this context, demanding technological and economical requirements like the use of high strength materials, the forming of very complex geometries, and the reduction of costs, particularly with regard to low volume production, must be achieved. Novel approaches in the field of sheet metal hydroforming are able to overcome existing limitations of conventional forming technologies and feature a higher potential for an effective manufacturing of lightweight structures. This paper shows the current research work at the Institute of Forming Technology and Lightweight Construction (IUL) in the face of sheet metal hydroforming with a special focus on the design of tool systems.

Color Tuning in Electroluminescent Textiles

2016 ◽  
Vol 100 ◽  
pp. 53-58 ◽  
Author(s):  
Evelyn Lempa ◽  
Carsten Graßmann ◽  
Maike Rabe ◽  
Andreas Kitzig ◽  
Edwin Naroska
Keyword(s):  
Zinc Sulfide ◽  
Organic Solvents ◽  
Dielectric Layer ◽  
Research Work ◽  
Transparent Electrode ◽  
Special Focus ◽  
Electroluminescent Devices ◽  
Light Emitting ◽  
Textile Materials ◽  
Additional Layer

Currently electroluminescent devices, operated by alternating current (AC-EL) on film, paper or textile are based on a capacitor with one transparent electrode and one generally non-transparent, highly conductive electrode and a light-emitting dielectric layer in-between. The light-emitting pigments are mostly based on doped zinc sulfide. Currently available commercial products contain encapsulated pigments dispersed in organic solvents. Those dispersions allow AC-EL-devices illuminating solitary in the colors white, green, blue-green, blue and orange. Blending those pigments leads to numerous new colors however, always linked to loss of brightness in the final device. In this research work the combination of fluorescent organic and inorganic dyestuffs with inorganic EL-phosphors was investigated. The AC-EL-devices were all based on textile materials; all dispersions were free of organic solvents. Special focus was directed to the concentration of dyes in an additional layer within the EL-capacitor as well as the thickness and particularly the positioning of the layer. In the result colors were achieved, which cannot be found by blending the phosphors, such as yellow and red. In addition, depending on the type of added fluorescent dyestuff layer, the brightness could be increased substantially.

KNOWLEDGE ACQUISITION AND PROCESS GUIDANCE FOR BUILDING SYSTEM DYNAMICS SIMULATION MODELS: AN EXPERIENCE REPORT FROM SOFTWARE INDUSTRY

2000 ◽  
Vol 10 (04) ◽  
pp. 487-510 ◽  
Author(s):  
DIETMAR PFAHL ◽  
KARL LEBSANFT
Keyword(s):  
System Dynamics ◽  
Knowledge Acquisition ◽  
Process Model ◽  
Model Building ◽  
Dynamics Simulation ◽  
Integrated Modelling ◽  
Special Focus ◽  
Problem Analysis ◽  
Dynamic Complexity ◽  
Process Guidance

System Dynamics (SD) is a method that allows for integrated modelling of technical as well as managerial aspects responsible for the dynamic complexity of systems. Therefore, simulation of SD models can also be a tool for problem analysis within software organisations. In this paper, experience with SD modelling of software processes and projects within Siemens is reported. Special focus is put on problems encountered during knowledge acquisition for SD model building, like inadequate guidance while conducting SD modelling projects, and insufficient methodical support for re-using available or generating missing knowledge. Both problems were addressed in a research project, jointly conducted by Fraunhofer IESE and Siemens Corporate Technology. One of the results of this project is a prescriptive process model for building SD models. This process model, which is briefly outlined in the paper, provides guidance for a systematic development of SD models in software organisations.

scholarly journals Transformation of the CIM Model into A PIM Model According to The MDA Approach for Application Interoperability: Case of the "COVID-19 Patient Management" Business Process

2021 ◽  
Vol 17 (05) ◽  
pp. 49
Author(s):  
Meryem Fakhouri Amr ◽  
Nezha Benmoussa ◽  
Khalifa Mansouri ◽  
Mohammed Qbadou
Keyword(s):  
Business Process ◽  
Process Model ◽  
Patient Management ◽  
Research Work ◽  
Class Diagram ◽  
Modeling Framework ◽  
Target Model ◽  
Model Driven ◽  
Transformation Rules ◽  
Independent Model

<p>Model-Driven Engineering (MDE) plays a very important role in improving the development of complex systems. It focuses more on modeling than on classical programming. In this sense, model transformation is at the heart of the Model Driven Architecture (MDA) approach which advocates the use of models throughout the software development cycle on two levels. The first being the transformation of the Computing Independent Model (CIM) into the Platform Independent Model (PIM) and the second concerning the transformation of PIM into Platform Specific Model (PSM).</p><p>The latter has been dealt with in the majority of research works while the transformation from CIM to PIM which represents the highest level is rarely discussed in research topics. It is for this reason and in the spirit of improving the process of transforming the CIM model into PIM according to the MDA approach, that we have developed this research work in order to propose a new method and new transformation rules for optimization of the business process "COVID-19 patient management". Our contribution consists of the semi-automatic transformation of the CIM model presented by the BPMN (Business Process Model and Notation) source model into a PIM target model presented by a class diagram by using a set of transformation and correspondence rules that we performed manually using the language ATL (Atlas Transformation Language). This automatic transformation of the two source and target models is provided by the Eclipse Modeling Framework (EMF) which executes the transformation rules described manually in ATL and generates the PIM target model as an XMI (XML Metadata Interchange) file representing the target class diagram.</p>

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