pa1778data.pdf

U.S. STEEL DUQUESNE WORKS
HAER No. PA-115
(Page 69)
Although the basic steps involved in the production and
delivery of pig iron at the Duquesne Works remained basically the
same throughout its history, the equipment which carried out
those steps changed significantly over time. At its inception in
1896, the four furnace plant was utilized not only for purposes
of iron production but also played a role in the research and
development of new practices.
One such test involved dramatically increasing the number of
tuyeres per furnace. Each of the new furnaces, which were laid
out linearly on a north-south axis, was 100'-0" high with a
hearth diameter of 14 , -0" and a bosh diameter of 22*-0". Blast
furnace numbers one and two (the first two put into blast) each
had ten 7" diameter tuyeres, while numbers three and four were
equipped with twenty 5" diameter tuyeres. By increasing the
number of tuyeres at the latter furnaces, plant engineers hoped
that the concomitant increase in the area of combustion would
result in higher furnace productivity. Another point in favor of
dramatically increasing the number of furnace tuyeres, the
engineers argued, was that the dead space between adjoining
tuyeres would be reduced, thus limiting the accumulation of
chilled stock. Chilled stock contracted the effective tuyere
area over time, thereby causing slips and irregularities in the
furnace.
Although the new blast furnace plant immediately set a world
standard for productivity of comparable size plants, the
performance of blast furnace number one, which consistently led
the way, belied the argument favoring a dramatic increase in the
number of tuyeres per furnace. By the end of 1896, for example,
a world wide production record of 572.7 tons per day was set at
blast furnace number one. Ten years later, in March of 1906,
moreover, with the plant continuing to lead the way in terms of
productivity by maintaining an average of 63 0 tons per day per
furnace, blast furnace number one averaged 7 60 tons per day. The
dramatic overall increase in productivity at the Duquesne plant,
then, must be attributed to its unique automatic raw materials
delivery system rather than to any increase in the number of
tuyeres per furnace. 2
Notable among other features of the new plant's iron
production and delivery system at the blast furnaces was its
casting facilities. Built around each furnace was a one story,
70 '-0" wide x 219'-O 1 ' long cast house, laid out on a east-west
axis. A narrow track, suspended from the roof trusses along the
center of each cast house, supported a 5-ton hoist which was used
to facilitate the return of cast house scrap to the furnace.
Located on each side of the hoist was a 10-ton overhead electric
crane which ran the length of the cast house. The cranes were