Intelligent Control System of BOF Steelmaking
0n the basis of analyzing BOF steelmaking characteristics, a prediction model and control model based on neural network were established. Taking endpoint temperature and endpoint carbon content as control target, oxygen-blown volume and added coolant were calculated, then endpoint control of convert steelmaking was realized. Simulation results show that the simulation result of endpoint temperature and carbon content are satisfying and control strategy is very effective. The application results demonstrate the efficiency of the method.
An Improved Dynamic Model of the Vanadium Extraction Process in Steelmaking Converters
The production process from iron ore to steel can be divided into several stages, among which the processes of vanadium extraction and steelmaking are two key technological sections. The products of vanadium extraction are important strategic resources for modern industrial countries, and the remaining molten iron after vanadium extraction provides the material used in the subsequent steelmaking processes. In some mechanism models of vanadium extraction and the steelmaking process, the contact area of the reactions is considered to be constant in the empirical formula; furthermore, even the masses of the molten steel and slag are taken to be constants. This paper presents an important improvement to the existing models, in which the contact areas of the slag–metal interface and the emulsion system are considered to be non-constant. The improved model is simple and easy to analyze theoretically. Theoretical analysis of the model equations can be used to explain the competitive oxidation between each element, as well as the oxygen conservation of the system. The numerical simulations are consistent with existing production data, showing that the mass fraction of vanadium can be reduced to the specified threshold after about 3.5 min of blowing, which provides an important reference for production control. Furthermore, it is shown that the model captures the “trapezoid” structure of the decarburization rate. This paper also considers the relationship between FeO and O, the numerical simulation partly reflecting the dependence between the concentrations of FeO and O. The improved model can be used to describe and predict the change of the molten steel and slag composition in the process of vanadium extraction, which provides a mathematical foundation for the automatic control of the vanadium extraction process.
Measuring Sheet Resistances of Dielectrics Using Co‐Planar Hydrogel Electrochemical Cells with Practical Applications to Characterize the Protective Quality of Paints on Sculptures
Electrical properties of thin dielectric films at the solid-liquid phase boundary are an important performance characteristic of many devices, coatings and sensors. In this paper, co-polymeric hydrogels of polyacrylic acid co-sulfonic acid, swollen with a salt solution to act as the solid electrolyte, were used to assess interfaces using electrochemical impedance spectroscopy (EIS) in a co-planar geometry. Silane-modified glasses were characterized by the co-planar hydrogel EIS cell and found to be distinguishable based on their surface monolayer chemistry. EIS measurements were also made on primed and painted metal substrates, using both test panels and an outdoor sculpture, Tony Smith's Stinger. The panels were then exposed to accelerated and outdoor weathering and showed degradation on the surface paint layers, which was observable electrochemically using EIS and confirmed visually by SEM. Electrochemical spectral features were compared between data from a standard paint-test cell versus this co-planar hydrogel cell; both cell types were able to measure coating capacitance, providing useful information about the condition of the bulk coating. Yet, sheet resistance (Rs) was a spectral feature seen only by the co-planar hydrogel cell. Thus, it can be concluded that the use of such co-planar hydrogel cells can provide an earlier warning sign to coating degradation and such cells provide a new type of spectral information that is not assessable by the standard geometry.