Brusa E.,Polytechnic University of Turin |
Morsut S.,Danieli SpA |
Bosso N.,Polytechnic University of Turin
Meccanica | Year: 2014
Shredders are used for comminuting the metallic scrap fed to the electric arc furnace and consist of a set of hammers connected to a main rotor, whose rotation converts the kinetic energy into a strong impact. Design of the hammer is still based on some daily practice, but often it looks insufficient to predict the effects of wear and the cracks monitored in service. To reduce costs and improve the product quality manufacturers of shredders urgently need for a design tool suitable to predict the hammer dynamic behavior, the damage of material and to locate the stress concentration. Unfortunately no comprehensive design approach was yet proposed in the literature. This paper investigates the behavior of an industrial prototype of shredder to develop such as design tool. A first rotor-dynamic analysis was combined with a numerical investigation, performed through the Multi Body Dynamics and Finite Element Method, respectively. Results were then compared to some experimental evidences. Damage effects were tentatively related to some design parameters, the material properties and the loading conditions of the hammer. Results were used to increase the performance of a new shredder hammer being designed by refining the cutting edge profile and by selecting a different material. © 2013 Springer Science+Business Media Dordrecht.
Brusa E.G.M.,Polytechnic University of Turin |
Morsut S.,Danieli SpA
IEEE/ASME Transactions on Mechatronics | Year: 2015
Vibration of electrodes in operation strongly affects the efficiency of the electric arc furnace (EAF) fed by ac current during the steel smelting process. Therefore, an effective control of the structural dynamics through an active system is a current goal of the 'intelligent manufacturing' approach. A vertical position control applied to each electrode allows keeping the arc length almost constant and reduces the effects of some electromechanical actions due to the mutual magnetic induction among the three electric phases. Nevertheless, control action needs for a detailed model of the whole system dynamic behavior. A new method for modeling the equipment behavior and somehow the process was implemented. A key issue was including into the model all the electromechanical coupling effects occurring in this system and suitably linking to the structural dynamics. Modeling activity was performed by resorting to the multibody dynamics and the finite-element method, while some analytical formulations were used to describe both the electric arc behavior and the control. A preliminary validation on a real plant was performed as far as the huge size of the system allowed and an assessment of the mechanical design of the EAF was completed. © 1996-2012 IEEE.
Bobig P.,Danieli SpA |
Perotti F.,Danieli SpA |
Bulfone M.R.,Danieli SpA |
Bhaumik S.K.,Danieli SpA |
Dal Moro G.,Danieli SpA
MPT Metallurgical Plant and Technology International | Year: 2013
In only six months from rolling the first coil, the new hot strip mill achieved a production of 68,0001 per week, which represents more than 80% of the rated capacity. In less than two months the plant was able to roll strips as thin as 1.2 mm - the plant's designed minimum strip thickness. Thanks to all the advanced actuators and a state-of-the-art automation system, this new hot strip mill has become an important asset for the steelmaker. This article describes the details of the plant and highlights its achievements and outstanding results.