The research of multi-modality control strategy of arc furnace electrode regulation
During the electric arc furnace work process, electrode arc lengths show strong random disturbs and lead to performance deterioration such as power consumption, product quality and electric network. Using a single control strategy can not satisfy the requirements of different work conditions. This paper bases on the experiences of experts, puts forward division measures of multi modality control strategy for different requirements to adjust to the smelting temperatures and power of different stages in steel making process. It identifies the feature motion state of the electric arc furnace on line, and then selects the optimal controller in different phases to deal with the problem. In this paper, multi-modality division, program implementation and algorithm model used in control strategy provide a theoretical basis and model reference for the optimal design of electric arc furnaces electrode regulator system.
Fused magnesia manufacturing process: a survey
This paper provides an overview of the manufacturing process of fused magnesia. A brief introduction to fused magnesia and its industrial production process are presented first. In order to meet the market requirements and reduce costs, fused magnesia industrial process begins to focus on these issues: high energy consumption, serious pollution, low utilization of raw materials. So the issues related to fused magnesia are reviewed. The literature work related to the fused magnesia manufacturing process is divided into four categories: modeling, optimization, control, and experimental constraints. As can be seen, with the continuous development of intelligent manufacturing technology, fused magnesia manufacturing process begins to emerge new opportunities. Research trends and opportunities are presented in the final section, with an emphasis on future potential intelligent technologies.
Neutron Residual Stress Measurements on Rail Sections for Different Production Conditions
Rail sectioning with subsequent neutron diffraction experiments has been used to assess residual stresses in the rails. In this study we present the results of neutron stress measurements performed at the NIST Center for Neutron Research (NCNR) on rail sections from rails that were produced under various conditions. Specifically, these are air-cooled, air-cooled and roller-straightened, head-hardened and head-hardened and roller-straightened. More significantly, a head-hardened and roller-straightened rail was also studied after service to elucidate evolution of the service-induced residual stresses. In the latter case both a transverse-cut slice and the central region of a 0.53 m long piece were studied. Measurements on this piece are the first in which triaxial stresses have been determined for an intact rail. Neutron strain measurements with 3×3×3 mm3 spatial resolution were successfully employed for transversally cut slices to verify the difference in the stress state depending on the production process. Although examination of slices allows determination of only two-dimensional stresses in the plane of the slice, additional measurements on obliquely-cut slices, which were also carried out, and utilization of FEM gives the possibility of reconstructing the full triaxial stress distribution. Together, these approaches provide a better understanding of rail fabrication and the possibility of improving the durability and safety of rails in the future.Copyright © 2004 by ASME