The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform

Alexander Medvedev - One of the best experts on this subject based on the ideXlab platform.

  • Model-based slopping warning in the LD steel Converter Process
    Journal of Process Control, 2009
    Co-Authors: Magnus Evestedt, Alexander Medvedev
    Abstract:

    The most prevalent steel-making Process is the basic oxygen steel-making (BOS) Process. Problems arise when the layer of foaming slag created on the surface of the molten metal exceeds the height of the vessel and overflows, causing metal loss, Process disruption and environmental pollution. This phenomenon is commonly referred to as slopping. A method for automatic slopping detection is described in this contribution. The sound signal from a microphone located in the off-gas funnel is Processed to obtain an estimate of the slag level in the Converter. A model describing the relationship between off-gas flow rate, pressure and the slag level estimate is updated recursively in time. The output error is fed to a change detector yielding a warning system with three alarm levels indicating the persistence of slopping symptoms. The algorithm was tested on data from 100 heats at SSAB Oxelosund. Slopping was correctly detected in 80% of the blows.

  • Cavity Shape Dynamical Modelling and Estimation in a Water Model of the Steel Converter Process
    Journal of the Japanese Society for Experimental Mechanics, 2007
    Co-Authors: Magnus Evestedt, Alexander Medvedev
    Abstract:

    Cavity Shape Dynamical Modelling and Estimation in a Water Model of the Steel Converter Process

  • SLOPPING WARNING SYSTEM FOR THE LD Converter Process - AN EXTENDED EVALUATION STUDY
    IFAC Proceedings Volumes, 2007
    Co-Authors: Magnus Evestedt, Alexander Medvedev, Mathias Thorén, Wolfgang Birk
    Abstract:

    Abstract The most common steel-making Process in the world is the basic oxygen steelmaking (BOS) Process. During operation, a layer of foaming slag is created on the surface of the molten metal to improve the Converter performance. Problems arise when the slag level exceeds the height of the vessel and overflows, causing metal loss, Process disruption and environmental pollution. A warning system, based on adaptive filtering and key Process parameter measurements is evaluated on data from 100 charges at SSAB Oxelosund. Slopping is correctly detected in 80% of the blows.

  • Steel Converter Process Control with Cooling Additives
    IFAC Proceedings Volumes, 2004
    Co-Authors: Doris Sokolov, Alexander Sbepeljavyi, Alexander Medvedev
    Abstract:

    Abstract The problem of controlling chemical composition and temperature of the molten metal in the steel Converter Process has been considered. An approximative mathematical model of the Process is derived by taking into account temperature adjusting additives typical to the current metallurgic practices. A new control algorithm bringing the Process state to a preassigned set point is suggested. Since none of the Process state variables are available for direct measurement, two different approaches to state estimation are considered and found feasible.

  • Adaptive control of the top blown oxygen Converter Process with respect to temperature and unknown external disturbances
    2003
    Co-Authors: Boris Sokolov, Alexander Shepelyavi, Alexander Medvedev
    Abstract:

    Adaptive control of the top blown oxygen Converter Process with respect to temperature and unknown external disturbances

Magnus Evestedt - One of the best experts on this subject based on the ideXlab platform.

  • Model-based slopping warning in the LD steel Converter Process
    Journal of Process Control, 2009
    Co-Authors: Magnus Evestedt, Alexander Medvedev
    Abstract:

    The most prevalent steel-making Process is the basic oxygen steel-making (BOS) Process. Problems arise when the layer of foaming slag created on the surface of the molten metal exceeds the height of the vessel and overflows, causing metal loss, Process disruption and environmental pollution. This phenomenon is commonly referred to as slopping. A method for automatic slopping detection is described in this contribution. The sound signal from a microphone located in the off-gas funnel is Processed to obtain an estimate of the slag level in the Converter. A model describing the relationship between off-gas flow rate, pressure and the slag level estimate is updated recursively in time. The output error is fed to a change detector yielding a warning system with three alarm levels indicating the persistence of slopping symptoms. The algorithm was tested on data from 100 heats at SSAB Oxelosund. Slopping was correctly detected in 80% of the blows.

  • Cavity Shape Dynamical Modelling and Estimation in a Water Model of the Steel Converter Process
    Journal of the Japanese Society for Experimental Mechanics, 2007
    Co-Authors: Magnus Evestedt, Alexander Medvedev
    Abstract:

    Cavity Shape Dynamical Modelling and Estimation in a Water Model of the Steel Converter Process

  • SLOPPING WARNING SYSTEM FOR THE LD Converter Process - AN EXTENDED EVALUATION STUDY
    IFAC Proceedings Volumes, 2007
    Co-Authors: Magnus Evestedt, Alexander Medvedev, Mathias Thorén, Wolfgang Birk
    Abstract:

    Abstract The most common steel-making Process in the world is the basic oxygen steelmaking (BOS) Process. During operation, a layer of foaming slag is created on the surface of the molten metal to improve the Converter performance. Problems arise when the slag level exceeds the height of the vessel and overflows, causing metal loss, Process disruption and environmental pollution. A warning system, based on adaptive filtering and key Process parameter measurements is evaluated on data from 100 charges at SSAB Oxelosund. Slopping is correctly detected in 80% of the blows.

Wolfgang Birk - One of the best experts on this subject based on the ideXlab platform.

  • SLOPPING WARNING SYSTEM FOR THE LD Converter Process - AN EXTENDED EVALUATION STUDY
    IFAC Proceedings Volumes, 2007
    Co-Authors: Magnus Evestedt, Alexander Medvedev, Mathias Thorén, Wolfgang Birk
    Abstract:

    Abstract The most common steel-making Process in the world is the basic oxygen steelmaking (BOS) Process. During operation, a layer of foaming slag is created on the surface of the molten metal to improve the Converter performance. Problems arise when the slag level exceeds the height of the vessel and overflows, causing metal loss, Process disruption and environmental pollution. A warning system, based on adaptive filtering and key Process parameter measurements is evaluated on data from 100 charges at SSAB Oxelosund. Slopping is correctly detected in 80% of the blows.

  • Foam level control in a water model of the LD Converter Process
    Control Engineering Practice, 2001
    Co-Authors: Wolfgang Birk, Alexander Medvedev, I. Arvanitidis, Pär Jönsson
    Abstract:

    This paper deals with estimation and control of foam level in dynamic foaming. An improved foam level estimation methodology from a microphone signal and its automatic calibration is presented. The dynamical reaction of the foam level on air lance movements is modelled using system identification. Based on the resulting mathematical model, a controller for foam level stabilisation is designed and applied to a water model, representing the LD Converter Process. It is shown that the foam level can be controlled using a microphone as the measurement device and air lance movement as the actuator.

  • Physical modeling and control of dynamic foaming in an LD-Converter Process
    IEEE Transactions on Industry Applications, 2001
    Co-Authors: Wolfgang Birk, I. Arvanitidis, P.g. Jonsson, A. Medvedev
    Abstract:

    This paper deals with physical modeling and control of dynamic foaming in the LD-Converter Process. An experimental setup consisting of a water model, digital signal Processor, and PC hardware is built and shown to be useful for studying dynamic foaming. Furthermore, a foam height estimation algorithm is presented and validated through experiments. Finally, sound signals from the LD-Converter and water model are compared and similarities between them are found.Validerad; 2001; 20061025 (ysko)

  • Physical modelling and control of dynamic foaming in an LD-Converter Process
    Conference Record of the 2000 IEEE Industry Applications Conference. Thirty-Fifth IAS Annual Meeting and World Conference on Industrial Applications o, 1
    Co-Authors: Wolfgang Birk, I. Arvanitidis, P.g. Jonsson, Alexander Medvedev
    Abstract:

    This paper deals with physical modeling and control of dynamic foaming in the LD-Converter Process. An experimental setup consisting of a water model, digital signal Processor, and PC hardware is built and shown to be useful for studying dynamic foaming. Furthermore, a foam height estimation algorithm is presented and validated through experiments. Finally, sound signals from the LD-Converter and water model are compared and similarities between them are found.

Pär Jönsson - One of the best experts on this subject based on the ideXlab platform.

  • A Physical Modeling Study on Slag Behavior in the AOD Converter Process
    steel research international, 2018
    Co-Authors: Nicholas Lundkvist, Manabu Iguchi, Anders Tilliander, Pär Jönsson
    Abstract:

    A water/oil physical model is built up to investigate the slag behavior under the side gas-blowing condition of an AOD Process. The critical side-blowing air flow rates for the top oil entrainment ...

  • Optimization of Combined Blown Converter Process
    ISIJ International, 2014
    Co-Authors: Xiaobin Zhou, Mikael Ersson, Liangcai Zhong, Pär Jönsson
    Abstract:

    A 1/6th scaled down physical model was used to study and optimize the stirring condition of a 30 t Converter. A number of parameters were studied and their effects on the mixing time were recorded. A new bottom tuyere scheme with an asymmetrical configuration was found to be one of the best cases with respect to a decreased mixing time in the bath. Mathematical modeling was employed to study the flow field characteristics caused by the new tuyere scheme. In the mathematical model, a comparison between the existing and the new tuyere setups was made with regards to the mixing time and turbulence in the bath. In addition, a new volumetric method for calculating the mixing time was applied. The results showed that, on average, a 23.1% longer mixing time resulted from the volumetric method compared to the standard method where discrete point are used to track the mixing time. Furthermore, an industrial investigation was performed to check the effects of the new tuyere scheme in a Converter by analyzing the [O], [C] and [P] contents in the bath. The results showed that the application effects of the new tuyere scheme yield a better stirring condition in the bath compared to the original case.

  • Foam level control in a water model of the LD Converter Process
    Control Engineering Practice, 2001
    Co-Authors: Wolfgang Birk, Alexander Medvedev, I. Arvanitidis, Pär Jönsson
    Abstract:

    This paper deals with estimation and control of foam level in dynamic foaming. An improved foam level estimation methodology from a microphone signal and its automatic calibration is presented. The dynamical reaction of the foam level on air lance movements is modelled using system identification. Based on the resulting mathematical model, a controller for foam level stabilisation is designed and applied to a water model, representing the LD Converter Process. It is shown that the foam level can be controlled using a microphone as the measurement device and air lance movement as the actuator.

A.v. Medvedev - One of the best experts on this subject based on the ideXlab platform.

  • Nonparametric modeling of oxygen-Converter Processes
    Steel in Translation, 2016
    Co-Authors: A.v. Medvedev, M. E. Kornet, E. A. Chzhan
    Abstract:

    Preliminary data analysis in the identification of multidimensional discrete–continuous Processes is considered. A method is proposed for generating a working sample from an initial training sample consisting of normal operating data. The method somewhat resembles the bootstrap Process. In the present case, the Process begins with a training sample that reflects the properties of the object to be identified. By means of the proposed method, the unknown stochastic dependence at the limit of definition of the corresponding input–output variables for the object may be automatically derived. The identification of the oxygen-Converter Process in Converter shop 2 at OAO EVRAZ ZSMK is considered in the case with insufficient available information and gaps in the observation sample. The model is based on a new working sample containing both the measurements and data generated by the proposed method. By using the working sample as a training sample, the precision of identification is doubled.

  • Stability of the solutions of the observation error equations at control of the steel Converter Process
    Automation and Remote Control, 2007
    Co-Authors: A.v. Medvedev, B.m. Sokolov, A. I. Shepelyavyi
    Abstract:

    Consideration was given to the nonlinear observer with the feedback sensitivity function which showed itself well in estimating the carbon and silicon content in the Converter melt on the basis of the nonlinear model with time-constant parameters. In the case of controlling the melt temperature by the cooling additives, the plant parameters vary in time, which requires additional studies. For the estimation error under permanent perturbations where the matrix of the linear part is time-dependent, the zero solution of the equation system was proved to be stable.

  • Adaptive control of the top blown oxygen Converter Process considering temperature and unknown external disturbances
    2003 IEEE International Workshop on Workload Characterization (IEEE Cat. No.03EX775), 1
    Co-Authors: Bods M. Sokolov, Alexander I. Shepeljavyi, A.v. Medvedev
    Abstract:

    The paper considers the control of the top blown oxygen Converter Process by exploiting the equations of the Process in order to compensate for unknown disturbances. These disturbances are caused by additives dissolving in the Converter. Necessity to take into account temperature of reaction has resulted in increase of number of the equations in the in the mathematical model of Process. Thus the speed of reaction now depends on the metal temperature. The dissipation region of the controller is evaluated. A nonlinear observer is developed for estimating the metal analysis in real time. It is shown that the observer is asymptotically stable and a region of attraction, where the estimation error converges, is derived. Adaptive control of this Process is constructed.

  • Relay control of the steel Converter Process by means of cooling additives
    Proceedings. 2005 International Conference Physics and Control 2005., 1
    Co-Authors: B.m. Sokolov, Alexander I. Shepeljavyi, A.v. Medvedev
    Abstract:

    The problem of steel Converter control by means of continuously manipulated cooling additives has been considered before. Here a more realistic situation when the control signal takes only two values i. e. zero or highest possible is treated.