RUSSULA NEWSLETTER No. 11

RECENT PROJECTS
Successful EAF upgrade at Votorantim Siderúrgia in
Barra Mansa, Brazil
Russula simplified the
control configuration to
one platform during the
EAF No. 1 upgrade at
Votorantim Siderúrgia.
The EAF was successfully
commissioned in January
of this year.
Votorantim Siderurgia contracted
Russula to upgrade the existing
electric arc furnace No. 1. at its Barra
Mansa plant located in Rio de
Janeiro, Brazil. In early January of
this year, the control system modernization
was successfully completed.
The EAF has a capacity of 51
ton/tap-to-tap cycle.
In this project, the existing control
configuration, previously provided
by multiple equipment suppliers,
was replaced with one single platform.
This simplified maintenance
and spare parts inventory. In particular,
the old MCC panel, Siemens
Step 5, Rockwell SLC 500 PLCs
were replaced with a new MCC
panel and a new Siemens Step 7
PLC. The Step 7 PLC is widely used
in the steel sector, to ensure spare
parts availability and minimize
electrical failure downtime.
EAF No. 1 Control Scope
The control funcionality of the EAF
No. 1 included:
- Energizing electrodes
- Steel melting process initiation
- Electrode and furnace
movement to the liquid steel
casting operation
- Interface with the electrode
regulation system
- EBT ladle car and retractable
platform movement
- Furnace tilting platform and
roof removal mechanism
The existing MCC panel, containing
logic performed by contactors and
relays, was responsible for the control
of the medium voltage unit, the
hydraulic unit, the electrode regulation
system and the furnace movement
system. The medium voltage
unit consisted of a motorized drive
disconnect and a main circuit
breaker to energize the electrodes
and start the steel melting process.
The hydraulic unit controlled the
electrode movements and furnace
movement to the liquid steel casting
operation. For the electrode regulation
system, the MCC interfaced
with an auxiliary PLC AMI-GE, responsible
for the regulation. Lastly
the furnace movements system consisted
of the logic of locking movements,
gate valve, furnace tilting,
roof lifting, roof removal mechanism
and opening of the slag door.
The existing PLC Siemens Step 5
contained the logic responsible for
the control and drive of the ladle car
EBT and retractable platform. The
PLC interfaced with an auxiliary
controller Tiefenbach, which was
responsible for triggering the
proportional valve for the furnace
Russula Newsletter No. 11 April 2015 - Copyright © by RUSSULA S.A. 20