In anticipation of next week’s annual Association for Iron and
Steel Technology (AIST) trade show, we are sharing a case study about a steel
mini-mill that solved a waste oil problem with the use of our Oil Skimmers.
NLMK Indiana (formerly Beta Steel) is a steel mini-mill that produces and sells
hot-rolled steel in the north central United States and Canada. The
plant produces about 700,000 tons a year and employs about 400
people.
NLMK Indiana’s raw
materials are scrap metal and chemical additives. The scrap
metal is melted and recast into slabs, which ultimately become
coils of flat steel that customers purchase to make a variety of
durable products. The heat-intensive process uses water to cool
in-process materials to specified temperatures.
During hot strip
mill production, tramp oil mixes with the water, and this mixture
collects in two basins and a scale pit. Before the water can be cooled and
reused, the oil must be removed to keep the cooling towers and other
plant equipment running smoothly, and to prevent contamination of the
product.
PROBLEM: The plant
had employed a company to periodically vacuum the oil out of the water as
it sat in the pit and two collection basins — one with a 490,000-gallon
capacity and the other one with a 285,000-gallon capacity. But this method did
not adequately separate the oil and water, and it didn't provide an
option to operate continuously, as the plant does.
SOLUTION:
NLMK Indiana
now uses six Oil Skimmers, Inc. oil-recovery systems to remove the
tramp oil from the water in the collection basins as well as from
a scale pit at the hot-strip mill. In a unique anti-clogging design,
the Oil Skimmers have a polyurethane tube that attracts and collects
the waste oil/grease as it floats on top of wastewater. The tube
passes through a scraper system to remove the oil, which flows into a
containment drum.
BENEFITS: The
system operates independently and can run 24 hours a day, seven days
a week. This was a significant improvement over periodic vacuuming, Ehren
Plew, Plant Mechanical Engineer, said. The skimmers run whenever needed
and for as long as needed.
“They are
relatively maintenance-free, and they are certainly trouble-free,” Plew
said. “They run 24/7 with no manpower. It would be uneconomical
to have a vacuum truck running 24 hours a day.” Additionally, the skimmers
are more effective at separation, according to Plew. “The vacuum truck
sucks out a lot of water, and these remove just the oil. So there is
a lot less waste.”
Jim Petrucci, Vice
President of Oil Skimmers, Inc., said the vacuum method of oil removal has
its place in the industry, but it’s not the best choice for an
ongoing need, such as steel mini-mills.
"Our system
runs continuously. Vacuuming is great when you have a spill, but
it doesn’t address continuous build up.”
NLMK Indiana
uses the Model 5H Oil Skimmer
and the Model 6V Oil Skimmer. Both are made with internal components
of high-strength steel and bronze for durability. External parts are made
from abrasive-resistant ceramic. The machine has a lifespan of more than
25 years.
If you have any questions or comments, please share! We love to hear from our readers!
Above: Model 5H Oil Skimmer side-mounted on a tank.
To see a video of the Model 5H in operation, visit our
Youtube page.
