Reprinted for Service Center Metals, ©2014 Light Metal Age
SCM Commissions Unique Remelt Plant
First in the World to Horizontally Cast 14" Billet
Skimming arm removes dross from the melting furnace main chamber of the new compact remelt plant.
I
f there’s one word in the English language that exemplifies Service Center Metals (SCM), it’s “unique.”
The Prince George, VA-based company is the only
soft-alloy aluminum extruder in North America,
perhaps the world, which sells its products exclusively
through metal service centers, commonly known as distributors. The company has a one-of-a-kind, incentivedriven culture where breaking production records is routine and company employees, commonly referred to as
TMs (Team Members), have named their two extrusion
presses “Elvis” and “The Boss.” In April 2014, the company completed commissioning of a new, unique compact remelt plant with two horizontal casting lines named
“Mick” and “Keith.”
The equipment in SCM’s compact remelt plant was
designed and supplied by Hertwich Engineering of
Braunau, Austria. Since this “compact type remelt” concept was developed by Hertwich in the early 1980s, over
30 such plants have been built around the globe. SCM
is the second in North America and, at 30,000 tpy, it
has the second-highest annual production capacity in
the world. With Mick and Keith installed and operating
in parallel to one another, the company’s new plant is
the only one in the world designed to cast two different
billet diameters, 9 inch and 14 inch, simultaneously. In
fact, SCM’s compact remelt plant is the first in the world
designed to horizontally cast 14 inch billet on a production scale.
When asked why the company chose the compact remelt concept, Scott Kelley, SCM’s president and ceo, said,
“Building a remelt facility is part of our strategic plan
to become vertically-integrated, further strengthen our
company, and position us for future growth in our core
extrusion business. We liked the unique flexibility and
scalability of the design. Just like our extrusion presses,
Elvis and The Boss, Hertwich’s equipment is well-designed and state-of-the-art. Overall, we thought the compact remelt concept would mesh well with our business
model. And, it has.”
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SCM’s method of installing the equipment in their
new remelt plant was unique as well. Typically, a company hires outside contractors for the mechanical and
electrical installation work for projects of this scale.
When the work is done and the contractors leave, the
knowledge gained through installation is lost. In contrast, SCM’s maintenance and production TMs installed
the equipment under Hertwich’s supervision. As a result, the learning curve to maintain and operate the
equipment was quick and the plant exceeded full production design rates shortly after commissioning in
April. Chris Berry, a supervisor in the new remelt plant
who previously supervised production crews in SCM’s
extrusion plant, was part of the team installing the remelt equipment. Regarding the installation, Berry said,
“It was an awesome experience working alongside the
engineers and programmers from Hertwich and learning the ins and outs of their systems. The training was
hands-on and thorough.”
Thanks to the sophisticated, automated design, the
compact remelt plant safely operates with minimal staffing, only 20 people for 24/7 production. The plant layout is shown in Figure 1.
Melting/Casting Furnace: Utilizing the latest technology associated with Hertwich’s Ecomelt line of furnaces, in this case an Ecomelt PR110 rated at a continuous melt rate of 5.5 tph, the furnace accepts clean and
slightly oily scrap delivered via preloaded charge bins
(Figure 2). Completely automated, the system delivers
the scrap onto a dry hearth; then the scrap bin retracts
back to its original starting position and the charge
door closes. This ensures complete isolation from any
operators and makes the loading of scrap into the furnace extremely safe. After a predetermined time the
scrap pusher is activated, pushing the preheated scrap
into the molten bath. Simultaneously the electromagnetic pump floods the preheat chamber ensuring a
quick and efficient melting process using submergence technology.
LIGHT METAL AGE, OCTOBER 2014
Figure 1. 3-D equipment layout of the compact remelt plant.
The charging machine also incorporates a skimming
arm on a separate cross car similar to the charging car. The
skimming tool is hydraulically weight balanced, spring
loaded, and elastically fixed to the machine head. This
avoids high forces of the skimming tool to the refractory
lining of the furnace. The skimming operation is precise
and smooth in order to obtain thorough skimming while
avoiding the removal of excess melt with the dross.
Using the molten metal pump the metal is transferred
into the holding chamber and ultimately the casting
chamber, whereby the metal is treated with a constant
argon flow prior to entering the casting launder and subsequent degasser and filtering system.
The furnace was also supplied with an air cleaning system designed to meet and exceed the latest EPA clean
air requirements. The filtering system was supplied by
Nederman.
Dual Casting Machines: The dual casting machines, Mick
and Keith, also supplied by Hertwich were designed to effectively cast 14 inch diameter and 9 inch diameter billets
simultaneously, providing SCM with greater production
flexibility. However, to date, the majority of material cast
has been 14 inch diameter. It should be noted that, prior
to the award of the contract, SCM and Hertwich worked
closely together on trials of 14 inch diameter billet to ensure success at the extrusion press.
Using the Hertwich-designed molds, the plant is able
to cast 14 inch billet continuously for at least six days
before mold changes are necessary (Figure 3). The best
campaign to date has been 11 days with even longer campaigns anticipated. This is a drastic improvement over
previous compact remelt installations, whereby mold
changes were required every four to five days. A typical
mold change currently takes 1-2 hours.
After being cut “on the fly” to the desired/required
length by the flying saw the billets exit onto an interim
accumulation conveyor system prior to entering the ultrasonic inspection station (Figure 4).
Ultrasonic Inspection & Continuous Homogenization: The
as-cast billet is then passed through a two head ultrasonic
inspection station (Figure 5). Fully automated, the system
checks for center cracks and major inclusions. Should the
whole log be unsatisfactory it is rejected. However, should
only a small portion of the log be deemed defective the
Figure 2. Scrap charging machine inserting preloaded bin in melting
furnace.
Figure 3. Cody Lofland, casting operator (left), and Chip Dollins, vp of
operations (right), observe 14 inch casting on Mick.
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LIGHT METAL AGE, OCTOBER 2014
Figure 4. Entry for log accumulation conveyor system.
Figure 5. Ultrasonic inspection.
system automatically (electronically) marks the billet for
defective portion removal via a saw after homogenizing.
As depicted in the layout arrangement (Figure 1), the
inspected logs are then transported into the continuous
homogenizing and cooling system. This is one of over
130 units that Hertwich has supplied around the world. It
incorporates state-of-the-art homogenizing heat up and
soak practices followed by a recipe driven cooling station
that provides SCM with the best heat treated extrusion
billet available in the industry to date. Once fully heat
treated the logs are then transported back to the extrusion shop for processing.
sion in 2006, the compact remelt project was completed
on time and on budget. SCM’s motto is “Can-Do” and
this attitude permeates the company’s culture and, as
a result, plans for expanding the compact remelt plant
are already underway. “Phase 2 of the compact remelt
will make us 100% self-sufficient in terms of billet supply,” said Kelley. Berry added “I’m confident that our
team of ‘Master Casters’ will be successful in running
this compact remelt plant and any future compact remelt plants. I’m looking forward to working with Hertwich again and learning more from their experiences
with casting.” That’s the SCM Can-Do attitude uniquely
personified.
Conclusion
Several aspects of this project were and are not unique
for SCM. Like the greenfield construction of the company’s extrusion plant in 2002 and its subsequent expan-
Editors Note: For more information about SCM’s complete extrusion and distribution facility see the Light Metal Age article from August 2013, “Service Center Metals: In a Land of
Hope and Dreams.”
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