Analysis of frames of operating metallurgical shops under reconstruction

Abstract

Introduction. A large number of industrial metallurgical shops, currently in operation in Russia, were erected in 1960–1980. Nowadays, these facilities need large-scale reconstruction to improve the production procedure and to install new, high performance and environmentally friendly equipment and automated control systems. Higher capacity production requires a change in the frame behaviour and the loads acting on it, in comparison with the design ones. It should be noted that the remaining service life of the frame is coming to an end in the harsh environment of a metal factory, and therefore, it needs a major overhaul and reinforcement to ensure smooth operation under the action of new loads.
 
 Materials and methods. To ensure the most accurate evaluation of forces and displacements in the frame elements and to design its reinforcement, it is advisable to perform a 3D analysis of the frame using the finite element method. This analysis must take into account current regulatory requirements, that are much tighter than those that were in effect when the frame was designed (for example, higher standard snow load, requirements ensuring protection from progressive collapse, higher values of some reliability factors, etc.).
 
 Results. The author describes the practical analysis of the frame of converter shop No. 2 at Novolipetsk Iron and Steel Works (NLMK), which was part of a reconstruction project, that included replacement of two converters with gas exhaust ducts and construction of a fugitive emission treatment system. The calculation model was described; loads acting on the frame of the converter shop were provided; principal combinations of loads and progressive collapse prevention actions were analyzed. The analysis confirmed that the bearing capacity of some structures was insufficient, and therefore, they were to be reinforced.
 
 Conclusions. Proper analysis of the stress-strain state of the frame was made using the finite element method. The bearing capacity of the converter shop frame was analyzed, and its effective reinforcement was designed according to current standards. Further research will be focused on improving the analysis by contributing the actual stiffness of joints, evaluating actual loads and ensuring the combined action of enclosing and other non-bearing structures.