pa1778data.pdf

U.S. STEEL DUQUESNE WORKS
HAER No. PA-115
(Page 205)
BOP shop's charging aisle. The scrap was loaded from the rail
cars directly into a scrap box (ranging from 1000 cu. ft. to 1500
cu. ft capacity) set upon a floor scale, by a magnet attached to
a E.O.T. crane. After weighing, the box was transported by the
crane to the furnace aisle's operating floor where it was placed
onto a scrap charging machine, traveling over a wide gauge track
in front of the furnaces. The machine hydraulically dumped the
contents of the box into the furnace which was rotated on its
trunnions to the charging position (at an angle of approximately
45 degrees toward the charging aisle).
Molten iron was delivered from the blast furnace plant to
the BOP shop's hot metal shed in "submarine" ladle cars. Each
ladle car was positioned next to one of two hot metal transfer
pits, where 175-ton charging ladles, resting on transfer cars,
were positioned by remote control to receive the charge of molten
iron. Before the molten iron was re-ladled, a proportioned
amount of calcium carbide was thrown into the bottom of the
charging ladle for the purpose of desulphurization. As the
molten material was transferred from the "submarine" car to the
charging ladle, the resultant fumes were directed up through a
fume hood to a bag house located on the eastern side of the BOP
shop. With the completion of re-ladling, the charging ladle was
picked up by an E.O.T. crane and transported across the charging
aisle to a skimming station where the slag, created by the
reaction of the molten metal with the calcium carbide, was
manually skimmed off the bath. The ladle was then lifted up by
the crane to the operating floor of the furnace aisle and charged
into the furnace which was rotated to its charging position. At
this point, the furnace was rotated to its upright or operating
position and the heat was begun by turning on the oxygen after
the oxygen lances had been dropped into place. Immediately after
the heat had started, fluxing materials were added to the
furnace.
Fluxing materials such as iron ore, fluorspar, and burnt
lime were periodically delivered from storage bins located at the
flux handling facility by means of a covered conveyor leading to
the top floor (flux storage floor) of the furnace aisle where
they were fed by gravity through a tripper into storage bins
located on the floor below (weighing floor). Materials were fed
from the storage hoppers by gravity to weigh hoppers on the
batching floor and automatically weighed. After weighing, the
materials fell onto conveyor belts which dropped them into the
batching hopper located on the service floor directly above the
furnace. The materials were eventually fed into the furnace
through an opening in its fume hood by means of a water cooled
chute attached to the bottom opening of the batching hopper.