pa1778data.pdf

U.S. STEEL DUQUESNE WORKS
HAER No. PA-115
(Page 153)
The north and south stockhouse sinter conveyor belts also
serviced one 6,000 cu. ft. capacity sinter fines bin and one
3,000 cu. ft. capacity scrap and scale bin each, the material
from these bins passed through a sinter weigh hopper before being
delivered by a chute to its respective skip car.
Upon being filled with raw material, the skip car was
hoisted up to the top of the furnace by means of a 275 hp direct
current motor/drive/winch drum assembly located in the elevated
hoist house. After reaching the furnace top, the car dumped its
contents into a receiving hopper where it was delivered by
gravity to the hopper of the revolving distributor. The
distributor sat directly on top of the small bell and was
designed to have a flexible rotating system. It could be set to
rotate a preselected number of degrees in increments of 60
degrees after the dumping of each skip car or it could be set to
spin continuously immediately before and during the dumping of
each car. Subsequently, the small bell was lowered by means of a
compressed air powered hydraulic cylinder located in the hoist
house until it had dropped its load onto the intermediate bell.
The lowering of the intermediate bell was accomplished in the
same manner in order to drop the raw materials onto the large
bell. Operation of the large bell was set to dump its contents
into the furnace proper after a preselected number of skip loads
had passed through the upper two bells onto it. The primary
advantages of the three bell system was its ability to handle the
larger raw material requirements of Dorothy 6 and to facilitate
the charging of raw materials into a furnace operating with high
top pressures without the loss of valuable gases. 10
The coke breeze removal system was altered in 1960 in
conjunction with the construction of Dorothy 6. The existing
conveyor and coke dust larry cars were succeeded by a 3 hp motor
powered 20" conveyor belt carrying coke breeze from the dust
hoppers under the vibrating coke screens to a 24" motor powered
main coke breeze conveyor running along the entire eastern wall
of the stockhouse to the newly built stockhouse for Dorothy 6.
From there the coke breeze was dropped into a chute leading down
through a skip pit into a waiting skip car with a capacity of 50
cu. ft. The skip car was periodically hoisted to an above ground
bin where it deposited its contents. 11
During the late 1960s the Neeland designed system at blast
furnace number 2 was dismantled along with the furnace itself.
This was the result of a "breakout" of molten ferro-manganese
through the lining and shell at the furnace's hearth. 12
When the blast furnace plant at the Duquesne Works was shut
down in 1984 it contained three generations of raw materials