Technology & Steel Application - News

Posted on 31 Jan 2013

New bucket charging system automates scrap feed in electric steel plants

A scrap charging system recently developed by Siemens has been used successfully in Riva SAM’s electric steel plant in Neuves Maisons, France, since June 2012.

Simetal EAF Chargeopt helps to optimize and fully automate crane movements during charging. Precisely repeatable movement patterns shorten charging cycles, reduce the need for maintenance and increase operational reliability as well as substantially improving work safety. The plant operator now commands a fully integrated automation system from the scrapyard to the electric arc furnace. Operations are controlled solely by the shift manager from the control room. The time for return on investment is less than one year.

The charging system installed in the Neuves Maisons steelworks includes a laserbased solution specially designed to pinpoint the position of the scrap buckets, and radio sensors which determine the position of the crane in the X and Y directions.

High-precision encoders report the Z position of the crane hook. These data are transferred via an industrial WLAN to a programmable logic controller where they are compared with the ideal pathway templates stored in the controller, which then initiates the necessary crane movements. Siemens supplied the mechanical and electrical equipment as well as the basic automation system. The new charging control and visualization system was integrated into the existing furnace control station interface.

Simetal EAF Chargeopt offers a number of advantages over manual operation. Irrespective of their size, shape or position on the car, scrap buckets are located and picked up precisely by the crane. The movement of the crane to the doghouse, the coupling of the auxiliary crane and the charging of the scrap into the electric arc furnace automatically follow an optimal, reproducible path. This saves time, prevents damage to the equipment and reduces hazards for personnel. Additionally, crane and doghouse movements are synchronized optimally, resulting in power-off-times of less than 1.5 minutes for charging. This increases oven productivity.

The measuring and data transmission systems are designed for use under rough ambient conditions, which boosts the availability of the entire system.

The Neuves-Maisons Works produces wire and reinforcing steels and is part of the SAM Division of the Riva Group, based in Milan, Italy. The plant produces steel in an electric arc furnace with a tapping weight of 150 tons and a ladle furnace. The steel is cast on a six-strand sequential billet casting plant, from which the billets pass to a rolling mill for further processing. A Siemens LiquiRob robot system is in use in Neuves Maisons since March 2010. It automatically takes samples from the electric arc furnace and performs measurements. The Riva Group was the first steel producer in the world to use a LiquiRob on an electric arc furnace.