Using robots in industrial
environments is far from a new idea. But while theyve
been used in automotive assembly plants for years, they are
rarely used in steel mills.
Austrias Siemens VAI
Metals Technologies GmbH would like to see that change through
the use of its Simetal LiquiRob flexible robot-aided measuring
solution, which has already been installed in about 10
steelmaking facilities in Europe, Asia and South America, with
three to four North American Free Trade Agreement (Nafta)
producers reportedly considering the new technology.
Siemens, an international
supplier of steel mill technologies, provides the automation
for the Simetal LiquiRob using industrial robots from several
Phil Ponikvar, business segment
manager for mechanical equipment at Siemens Industry Inc.,
Canonsburg, Pa., acknowledged that the steel industry has been
somewhat reluctant to use robotics. However, he said, its
a technology whose time has come, especially given the number
of injuries and fatalities in the hot end of steelmaking
facilities each year, as well as steelmakers desire to
provide high-quality steel products that closely conform to
increasingly stringent end-user requirements.
When the Simetal LiquiRob
technology was developed about five years ago, Ponikvar said,
it was mainly to improve safety in the hot end of steelmaking
plants by having a robot do some of the normal day-to-day,
heat-to-heat operations within the steel plant, such as taking
temperatures or chemical samples in the furnace or in the
casting machine tundish.
In a steel mill environment,
particularly where liquid hot metal is produced or manipulated,
operators are continually exposed to dangerous working
conditions. This is true for workers both at electric-arc
furnace (EF) and basic oxygen furnace (BOF) operations, as well
as those at continuous casters, secondary metallurgical plants
Using a robot is
unbelievably safer. There is no chance that sparking or boiling
of steel will result in splashback on a worker, Ponikvar
said. What we wanted to do was to eliminate the need of
having humans doing some of these more dangerous jobs, but what
we found afterwards was that we werent only able to
assist in improving safety, but we were also able to allow
steelmakers to have an operation that was more stable and
controlled than it had been previously.
He said that with each
temperature reading or chemistry sample being taken at the same
depth at the same location in the furnace or the tundish, the
steelmaker gets guaranteed consistency and repeatability in
Still, steelmakers have been
slow to accept the use of robots such as the Simetal LiquiRob
in their facilities. One factor contributing to this is that
labor unions see them as eliminating personnel. The way
that we look at it, though, is that you cant put a price
on safety, and those people could be reassigned somewhere else
in the facility, Ponikvar said.
Another major area of concern is
the robustness of robotics in a steel plant, he said, but that
is because 20 to 25 years ago there were various robotic
manipulator arms used in steel mills that couldnt stand
up to the harsh environment. Weve come a long way
in making heavier, sturdier, stronger robots since then,
Ponikvar said, evidenced by the number of robots doing welding
in auto plants, which also have nasty
The pricing of robots also is a
concern, but Ponikvar said that robots like the Simetal
LiquiRobÑwhich is able to perform many different
functions in the mill in a very repeatable fashionÑcould
help steelmakers cut costs as well as improve safety, leading
to a higher return on investment. While the payback period
varies on the specifications and functionality of a robot, it
is a maximum of 24 months for the LiquiRob, he said.
Ponikvar said there will come a
day when robots like the Simetal LiquiRob will be as common in
steel mills as they are in automotive assembly plants, although
it could take another 15 to 20 years, with acceptance likely to
come elsewhere in the world before North America. Right now,
while some other robots have found some limited use in steel
mills, performing one or two functions at the most, as far as
he is aware the LiquiRob is the only such robot being used to
perform operations in the EF, BOF and continuous caster.
The Simetal LiquiRobs
worldwide installations include the EF at Riva Fire SpA in
Neuves Maisons, France; BOFs at ThyssenKrupp CSA in Brazil and
JSC Zaporozhstal, Ukraine; and continuous casters at
Brazils Cia. Siderurgica Paulista (Cosipa), Poscos
Gwangyang, South Korea, facility and Voestalpine Stahl
GmbHs Linz, Austria, steelmaking complex. While three or
four North American companies have expressed interest in the
Simetal LiquiRob for several of their operations, none has
pulled the trigger yet.
About half of the Simetal
LiquiRob installations were retrofits, with the rest installed
in new or expanded steelmaking facilities. Provided they
have the room, it is easy to install, wire up, program and
operate, Ponikvar said, adding that size depends on the
available options. It could take up as little space as 6 feet
by 6 feet or as much as 15 feet by 25 feet.
In the furnace area of the melt
shop, Ponikvar said, the Simetal LiquiRob is able to take both
temperature and chemical samples in a repeatable fashion to
ensure uninterrupted, fail-safe and controlled steel
production. This, Siemens said, could have a direct influence
on the quality of the steel being produced as well as
productivity, thanks to faster cycle times and fewer
The same is true of EF oxygen
lancing or BOF sublancing, hazardous tasks the LiquiRob is able
to perform with an operator supervising it from the safety of
the control room.
With its six-axis movement, the
Simetal LiquiRob can be used in extremely tight conditions.
This means that very short cycle times can be achieved, and it
can be used for handling various kinds of cartridges without
any major modifications. In fact, the LiquiRob recognizes
defective cartridges and sorts them out before taking any
measurements, therefore minimizing measurement errors.
In the continuous caster area of
the steelmaking plant, the Simetal LiquiRob can perform tasks
in three areas: the ladle area, the tundish area and the mold
area. In the ladle area, operations such as media and signal
connections could be implemented. Connection of the ladle slide
gate cylinder also can be performed.
In the tundish area, not only
can the Simetal LiquiRob perform similar temperature and
probe-handling operations as it does in EFs and BOFs, it also
can feed an insulation powder used to prevent any oxidation
from occurring in the tundish, as well as carrying out ladle
shroud manipulations. The ladle shroud is placed on the ladle
to prevent reoxidation from occurring when steel flows from the
tundish and needs to be inserted and retracted at appropriate
times. Ponikvar said that when the ladle shroud needs to be
exchanged or cleaned, the Simetal LiquiRob is able to do that.
It takes an oxygen lance and cleans the steel or slag
buildup so the shroud can be reused instead of being
discarded, he said.
In the mold area, the LiquiRob
could dose the casting powder, as well as exchange submerged
entry nozzles, remove slag and insert separator plates.
Siemens said the centerpiece of
the Simetal LiquiRob for many applications is its optional
position detection system, a twin video camera sensor mounted
on the robot arm. From a reference plate mounted on the ladle
or tundish, the system analysis position moves in three
deviations in all three axial directions in addition to
rotations. The deviation parameters are automatically
transferred to the robot control system, allowing for a high
degree of measuring accuracy and observational flexibility as
well as excellent position measuring results in many adverse
Ponikvar said the Simetal
LiquiRob and other robots have a bright future in steel mills.
I think that everyone is continuing to not only look at
their safety records, but at what they can do to improve their
costs and profitability. If they could have a piece of
equipment that provides this type of repeatability and that
also improves safety, productivity and the quality of their end
product, then they are all for it.