LONG PRODUCTS BULLETIN - SMS Meer GmbH

Furnace and rolling mill
Reheat furnace.
Reheat furnace. The stock re-heating to
rolling temperature is performed by a 200
t/h walking-beam reheating furnace. With
dimensions of 52’ wide by 76’ long, the
furnace is equipped with a total of 64 ultralow
NOx burners providing a maximum total
330 mmBTU/h (BTU = British Thermal
Unit), corresponding to 83 Gcal/h. In order
to simplify the control system and to increase
the efficiency at the same time, the
furnace is divided into seven independently
controlled heating zones plus one unfired
zone. The combustion air is supplied
to the furnace by two centrifugal fans via
an air recuperator where it is heated up to
a maximum temperature of 550 °C. A dilution
air blower provides safety cold air in
case of overheating. Furnace charging is
through a frontal door while discharge is
laterally.
SMS Meer supplied the furnace inclusive
of the level 1 and level 2 controls. The latter
includes several heating curves (related
to the different product mix of size and
lengths), the control of the digital operation
of the burners and the furnace operation.
At the exit of the furnace, a high-pressure descaler (210 bar)
prepares the stock for rolling. The roller table feeding the mill
is provided with insulating covers to minimize temperature
losses. Shaping takes place in a continuous mill made of 15
stands, in horizontal, convertible and universal positions. All
stands are of the same size and are based on the innovative
SMS Meer CS stand design.
Structure of rolling mill
Roughing mill with stand changing car.
n Roughing mill: made up of five stands, with stands 1, 3 and 5
being convertible and 2 and 4 in two-high (horizontal) design. A
flying crop shear follows the roughing mill.
n Finishing mill: composed by the final ten stands, in two-high
or universal stands. A crop shear is installed downstream of
stand No.11, a final dividing shear is installed at the end of the
mill. A laser profile gage immediately precedes the dividing
shear.
The mill is equipped with quick-changing cars that allow a complete
size change in 20 minutes. The mill is characterized by a high
degree of flexibility thanks to: convertible stand design on the
roughing mill (Pos. 1, 3 and 5), possibility of using universal rolls in
eight of the ten finishing mill positions, availability of several initial
material sizes.
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Newsletter No. 3/2009 35