R.H.S. Paneltech Ltd. introduces a revolutionary new design in Ladle Arc
Furnace Roofs. This design utilizes a patented design and technology to
improve operation and reduce operating costs.
Conventional Roof Design
Conventional roofs are constructed of round tube or pipe.
This type of construction presents an irregular surface to the melt. This
surface offers ample areas for slag to adhere. This adhering slag presents
several problems. It imposes an additional load on the roof lifting
mechanism, it poses a threat to personnel working on or under the roof and the
roof can be damaged when the slag is removed.
In conventional construction the usual route for the
fume exhaust is through the electrode ports. There are several
disadvantages to this arrangement. First is accelerated electrode wear due
to erosion by the fume. Next is the fact that nitrogen is picked-up by the
melt because of the outside air being drawn across the surface of the metal.
Finally the inefficiency of this method of fume exhaust allows a large
amount of the fume to escape into the shop.
Disadvantages of conventional roofs:
-
Slag adherence due to pipe type construction.
-
Excessive electrode graphite wear
-
Pick-up of nitrogen by the melt
-
Escape of fume into the shop area
Paneltech Peripheral Extraction
Roof Design
The secret to the success of the Paneltech design is the utilization of
hot-formed rolled hollow rectangular sections in the construction of all
water-cooled components. This is especially an advantage when applied to
LMF/LAF roof construction. As seen in the above illustration, this
construction method presents a smooth flat surface to the melt. Slag and
metal splashes will not stick to this surface.
The fact that there is no slag adherence with this type of construction
allows Paneltech to design a roof with a primary exhaust duct located around the
entire periphery of the roof. This cannot be accomplished efficiently with
pipe type construction because the adhering slag will block the peripheral
exhaust path.
The advantages of the Paneltech peripheral fume extraction roof design are
numerous.
Design Advantages:
-
No slag adherence. The unique construction utilizing
the Paneltech
patented square hollow section construction provides a flat internal face in
the ladle roof. This surface is virtually immune to slag adherence and
therefore no mechanical means of slag removal is required. This in turn,
reduces furnace downtime, roof maintenance and exhaust duct blockage.
-
Elimination of fume egress to shop floor. Fume exhaust is around the
entire periphery of the ladle roof and exits through and opening that cannot
be blocked by slag. This greatly reduces the impact on the environment
from harmful gases
-
Reduction in loss of electrode graphite. The vast
majority of the fume exhaust is along the
entire periphery of the ladle and therefore greatly reduces erosion of the
graphite at the annulus.
-
Reduction and/or elimination of nitrogen gas pick-up during
the processing of the ladle. Once again, this is due to the fact that
the fume exhaust path is around the periphery of the ladle as opposed to a
duct on the furnace roof and no shop air is drawn across the melt.
-
Reduction in exhaust fan power. Due to the efficiency
of the peripheral fume duct design our customers have reported reductions in
required exhaust fan power of up to 60%.
-
Reduction is dilution air requirements. The
peripheral fume design naturally mixes dilution air with the fume at the lip
of the ladle. These results is much cooler temperatures in the exhaust
system ductwork and greatly reduces or eliminates the need for dilution fans.
-
Increased refractory life to to more efficient cooling.
Installation at CORUS, Lackenby, United Kingdom
A Paneltech Ladle Arc Furnace Roof with peripheral fume extraction has been
in operation at CORUS in Lackenby for over two years. The customer has
commented that they have been able to reduce the bag house fan power by 60%, are
experiencing no measuring fumes escaping into the plant and have noticed a
significant reduction in graphite wear. We can supply the name and number
of a contact at the plant upon request.
