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.
