pa1778data.pdf
pa1778data.pdf
pa1778data.pdf
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U.S. STEEL DUQUESNE WORKS<br />
HAER NO. PA-115<br />
(Page 74)<br />
at predetermined intervals to make recordings. A 70 , -0" long<br />
eleventh probe, equipped with eight thermocouples, was inserted<br />
permanently into the burden vertically from the furnace top. The<br />
data which these probes provided was expected not only to lead to<br />
improved production but also to give engineers vital information<br />
concerning future blast furnace design.<br />
An exceptional feature of Dorothy's casting facilities was<br />
its two tap holes or iron notches. Located at a 90 degree angle<br />
from each other, the tap holes emptied into two sets of parallel<br />
iron runners, each of which fed four 175-ton "submarine" ladle<br />
cars. The ladle cars were run into the one story, 80'-0" wide x<br />
250'-0" long cast house on four parallel hot metal tracks located<br />
on each side of the iron runners. One runner, then, served two<br />
hot metal tracks. As such, the relationship between the casting<br />
facilities inside of the cast house and the furnace's two tap<br />
holes significantly shortened the delivery time of the molten<br />
iron to the work's steelmaking plant. 6<br />
The plant's iron and ferromanganese production and delivery<br />
system changed significantly between the late 1960s and 1980<br />
because of events within the plant, corporate reorganization<br />
policies, and an investment in advanced desulphurization<br />
technology. The production of ferromanganese at Duquesne, for<br />
example, received a mortal blow when a breakout of the molten<br />
material destroyed blast furnace number two in the late 19 60s.<br />
The most consistent producer of ferromanganese in the plant, the<br />
furnace was eventually torn down in the mid-1970s.<br />
Coming on the heels of the accident, corporate officials<br />
decided to merge the National Works in McKeesport with the<br />
Duquesne Works in 1969. Based on the more modern iron and steel<br />
making facilities on the Duquesne site, the move required that<br />
the National Works shut down its own iron and steelmaking<br />
operations while drawing upon Duquesne for all its semi-finished<br />
steel needs. As a result of its increased iron making<br />
responsibilities, all of the Duquesne furnaces were put on iron<br />
production. Additionally, the working volume of blast furnace<br />
number four (from 31,504 to 35,215 cu. ft.) was upgraded as was<br />
Dorothy Six's (to 58,045 cu. ft.). All ferromanganese<br />
operations, moreover, were shifted to the McKeesport site.<br />
The decision to build a modern desulphurization facility in<br />
1980 on blast furnace plant grounds was taken to increase the<br />
efficiency of Duquesne ! s basic oxygen steelmaking furnaces. With<br />
the advent of basic oxygen steelmaking, iron desulphurization was<br />
performed externally by blowing calcium carbide through a lance<br />
into the molten bath and skimming off the resulting slag before<br />
the iron was charged into the oxygen furnace. At Duquesne, the