pa1778data.pdf
pa1778data.pdf
pa1778data.pdf
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
U.S. STEEL DUQUESNE WORKS<br />
HAER No. PA-115<br />
(Page 153)<br />
The north and south stockhouse sinter conveyor belts also<br />
serviced one 6,000 cu. ft. capacity sinter fines bin and one<br />
3,000 cu. ft. capacity scrap and scale bin each, the material<br />
from these bins passed through a sinter weigh hopper before being<br />
delivered by a chute to its respective skip car.<br />
Upon being filled with raw material, the skip car was<br />
hoisted up to the top of the furnace by means of a 275 hp direct<br />
current motor/drive/winch drum assembly located in the elevated<br />
hoist house. After reaching the furnace top, the car dumped its<br />
contents into a receiving hopper where it was delivered by<br />
gravity to the hopper of the revolving distributor. The<br />
distributor sat directly on top of the small bell and was<br />
designed to have a flexible rotating system. It could be set to<br />
rotate a preselected number of degrees in increments of 60<br />
degrees after the dumping of each skip car or it could be set to<br />
spin continuously immediately before and during the dumping of<br />
each car. Subsequently, the small bell was lowered by means of a<br />
compressed air powered hydraulic cylinder located in the hoist<br />
house until it had dropped its load onto the intermediate bell.<br />
The lowering of the intermediate bell was accomplished in the<br />
same manner in order to drop the raw materials onto the large<br />
bell. Operation of the large bell was set to dump its contents<br />
into the furnace proper after a preselected number of skip loads<br />
had passed through the upper two bells onto it. The primary<br />
advantages of the three bell system was its ability to handle the<br />
larger raw material requirements of Dorothy 6 and to facilitate<br />
the charging of raw materials into a furnace operating with high<br />
top pressures without the loss of valuable gases. 10<br />
The coke breeze removal system was altered in 1960 in<br />
conjunction with the construction of Dorothy 6. The existing<br />
conveyor and coke dust larry cars were succeeded by a 3 hp motor<br />
powered 20" conveyor belt carrying coke breeze from the dust<br />
hoppers under the vibrating coke screens to a 24" motor powered<br />
main coke breeze conveyor running along the entire eastern wall<br />
of the stockhouse to the newly built stockhouse for Dorothy 6.<br />
From there the coke breeze was dropped into a chute leading down<br />
through a skip pit into a waiting skip car with a capacity of 50<br />
cu. ft. The skip car was periodically hoisted to an above ground<br />
bin where it deposited its contents. 11<br />
During the late 1960s the Neeland designed system at blast<br />
furnace number 2 was dismantled along with the furnace itself.<br />
This was the result of a "breakout" of molten ferro-manganese<br />
through the lining and shell at the furnace's hearth. 12<br />
When the blast furnace plant at the Duquesne Works was shut<br />
down in 1984 it contained three generations of raw materials